Ceramic Ware Restoration

By James McCartney

http://www.james-mccartney.co.uk/

This is a web document which makes extensive use of internal and external hyperlinks to refer to related and more detailed information. If you wish to print part or all of it, it will print in .pdf format, or can be saved as a .pdf document - at least from Windows 10. There is no copyright – help yourself!

Version 1.1: December 2016

CONTENTS

INTRODUCTION …. to the subject, and to the author.

BEFORE YOU BEGIN Read this before you get involved!

OVERVIEW of CERAMICS What they are, how they are made

THE WORKSHOP A summary of the stuff you will need

STAGES in REPAIR and RESTORATION How to do everything:

Inspection Recording And Pricing

Dismantling

Cleaning And Stain Removal

Principles of Assembly

Adhesives And Applications

Smoothing Joins And Filling Chips

Modelling And Casting Missing Parts

Painting and Decoration

Final Inspection

EXAMPLES OF RESTORATION Some things I have done

EQUIPMENT MATERIALS and TOOLS and where to get them

INDEX



But IF YOU ARE ALREADY a HOBBYIST or PROFESSIONAL

To save you reading a lot of stuff you already know, here are some links to useful methods and recipes which I have developed, and which so far as I know are not recorded anywhere else.:




INTRODUCTION

This is about the repair and restoration of ceramic ware. It is aimed at the hobbyist or semi-professional who is interested in the ceramics, and treats the subject in some depth. I am writing about ornaments and tableware (and ignoring such items as bathroom ware, dentures, tiles, bricks, fire-clay and other industrial products.

It may also be of use to the handyman who has broken some valued ornament, and would like to be able to mend it. He can learn how to make a tidy join; but to replace missing bits or to make invisible joins requires a greater investment in tools, materials, and time. Like myself, perhaps he will find it an interesting challenge.

Maybe you have broken a white plate and joined it up with Araldite or Superglue? It looked dreadful, so you put some white paint on it to cover the join. It looked WORSE! (it works all right on wood!) Like to find out why?

In what follows, you will learn why it looks bad, and how to make it better, and also:



You must understand at the outset that the essence of this craft is to repair and restore items of a particular sort of material, using materials of an entirely different kind.

You CANNOT repair or restore ceramics by the same processes as they were originally made. ( I will not go into the technicalities here)

Ceramics are about the most durable things made by man; and if they are not damaged by impact, nor subject to harsh abrasion or caustic alkali, they will last for millennia, and often still look as good as new, after a wash.

For restoration we have to use materials which are different and less durable than the original ceramic, that is, adhesives and paint, to make the restored item look as close as possible to the original, and with any luck, to last for another few generations.

This means that TABLEWARE should be restored ONLY for ORNAMENTAL purposes or very occasional use, and preferably not to be in contact with any food or drink - you cannot know what toxicity or allergy will emerge. I have also determined that no paint or adhesive which I have ever used is resistant to repeated washing, although some lasted a good while. Any customer should be warned.



My career and experience: I graduated from Queen's University, Belfast, in 1959 with a degree in Applied Chemistry, specialising in textile, dye, and polymer chemistry, and then studied for a diploma in dye chemistry and colour physics from the Society of Dyers and Colourists. I followed a career at management level in textile bleaching, dyeing, printing and finishing for over twenty years, until the decline in the British textile industry required me to seek another career, so I moved into the burgeoning computer field, specialising in systems analysis and communications, and Unix systems management.

During this time I started repairing and restoring ceramic ornaments as a hobby, and as something totally different from ICT work! When I reached retirement age at the end of 2002, I took this up as a paying hobby, and in 13 years I restored over 1700 items. At the age of 78, I was now ready for a more complete retirement.

Initially I learned a lot from the limited amount of published literature on the subject, but many of the methods described here I have developed myself, and these may be of interest to other professionals. I have a degree and much experience in applied chemistry, and in colour physics, dye and pigment chemistry. This was very helpful in the experimental work involved, and in the consideration of health and safety measures..

Please note that, since I live in the United Kingdom, all products and sources which I use refer to those available there.




BEFORE YOU BEGIN

If you are even just thinking about this subject as a means of self-employment you must know a few important things:

  1. Is your colour vision good? About 1 in 12 men, and 1 in 1000 women, have defective colour vision. This is a genetic thing and cannot be cured. But because you can only see through your own eyes, you may not realise you are affected.

    The most frequent problem is a limited ability to distinguish between red and green. This can lead to you painting repairs which look just fine to you, but like grotesque mismatches to your customer. You can carry out a quick check at http://www.colour-blindness.com/colour-blindness-tests/ishihara-colour-test-plates/ If the results seem doubtful to you, get checked by a professional; look up “Ishihara Test” on the web or consult your nearest optician.

  2. There is not much money in it. The fact is that the value of antique porcelain or pottery, or high-class recent items, rarely exceeds a hundred pounds, and even less if it's restored. Watch some of the antiques programmes on the television if you don't believe me. Now if you rate your time at say £10/ hour (in 2015, and before expenses and tax) a comprehensive smash is likely to take the cost of restoration far above the market value of your customer's restored item. You will also need to spend money on setting up a workshop with tools and materials – See below !

    In practice, much of the work comes from people who have broken an otherwise fairly worthless item, but which has great sentimental value, or is part of a set. But it helps if you have another source of income, such as a pension (like myself).

    Some folk have tried to make a living by buying damaged items, restoring them, and selling them at a better price. If you know enough about the subject to recognize what has potential value, you would be better off 'bargain hunting' (as seen on television)

  3. You need to know the local antique dealers. Firstly, antique dealers sometimes acquire items with small damages or get items damaged in their shop, which are well worth restoring. Secondly, many people who break their own ornaments will often go to the nearest dealer to find out who can do the job. The third and important source of work comes from collectors, whom you will get to know via the dealers. If you don't know the dealers already, go round and introduce yourself, once you get set up. Get a business card at http://www.vistaprint.co.uk/ :




  1. The Web: A lot of your customers, other than dealers and collectors, will be ladies of a certain age who have not participated in the digital revolution, so a presence on the web is not as helpful as you might suppose – though their menfolk, if any, will sometimes find you on the web. As far as I am concerned, being also a former CIT systems person, I wrote my own website; don't spend a lot of time or money on this direction. Free entries on on-line business directories are well worth the trouble, some of them go round and pick up on your website anyway. Don't pay extra.




OVERVIEW of CERAMICS

This section gives a broad survey of ceramic wares. If you are already familiar with the subject, you can skip this!

To the average home handyman, they are a funny sort of material; unlike wood or metal or plastic, you can't cut or bend them or carve them to shape; they are very hard but they break easily, and trying to mend them when they are broken is often a source of deep frustration!

WHAT ARE CERAMICS?





For a well-illustrated account for modern porcelain production, see Rosenthal - Porcelain Production

To see some of the items which I have restored, by manufacture or type, see my old website (with links in the box at the bottom of the front page)



WHY DOES ALL THIS MATTER TO THE RESTORER ?

  1. Porous materials and solid materials need different type of adhesive: thin adhesives make a tidier join, but will soak into a porous material away from the join, leaving it very weak! So you have to use thicker adhesives....

  2. Glazing alters the appearance of the surface, and therefore alters the way in which it must be painted:



Take a small brush, and apply a stroke of some ordinary white gloss paint to a shiny (glazed) white plate; let it dry. You can see at once a clear outline of your paint, all round the brush stroke. This is because the glaze (a sheet of glass) separates the paint from the white reflecting surface, so the edge of the paint casts a shadow on the white surface below it. (Besides, it's probably not the same colour of white!)

More of these matters later!




THE WORKSHOP

You cannot go out and buy a kit for mending ceramics, in the way that you can for example get a basic water-colour kit. The tools and materials described in the following notes are (mostly) produced for other purposes, and have to be acquired from a variety of suppliers. There are very few suppliers who make any sort of speciality of it, but the problem of assembling a set of varied tools and materials has been greatly eased by the advent of internet trading.

IF YOU ARE THINKING OF MAKING THIS A PAYING PROPOSITION please note that you will need to spend a good deal of money on setting up some sort of workshop.



TOOLS and EQUIPMENT: The major items are: (follow hyperlinks for details and suppliers)



MATERIALS:

I started out in this sort of work before acrylic paints were well established, and have not converted to them, and have always used solvent-based paints and glazes in the finishing stages. I will give my views on this choice later, under Redecoration.

Water-based acrylics are now very versatile, and if you are starting out in this field, they are well worth considering. Lesley Acton has described their use in a couple of books (check on Amazon) and Addington Studios are well established suppliers. - but since I have not applied them in practice, I cannot comment on them.... but if I were starting again, I would try using them for secondary decoration at least (that is, the decoration applied, after you have applied the ground colour – flowers, borders etc.)

Stuff you need: (See also Appendix 1)



HEALTH and SAFETY; Workwear.

IF ALL THAT HASN'T PUT YOU OFF, READ ON!




STAGES in REPAIR and RESTORATION

REPAIR in this context means, to clean and mend a broken item, at least to prevent further damage.

RESTORATION generally means (a) repair (b) re-modelling missing bits (c) redecoration, so you can't see the joins of the repair. (A museum restoration may leave out redecoration, or make it different from the original, to show exactly what has been restored.)



BATCHING: Each of the following stages requires different tools and materials, and it is often necessary to leave workpieces for some time: to dry off after washing, to allow adhesives and fillers to set; to allow paint to dry, and so forth.

If you are in this as a business, it makes a lot of sense to take a batch of at least half-a-dozen workpieces through the process stage by stage at the same time; this means that you use the same tools, materials and methods on several items in immediate succession, saving you much time in cleaning up between processes, and waste of materials, and leaving natural overnight breaks as frequently required.



Inspection Recording And Pricing

Dismantling

Cleaning And Stain Removal

Principles of Assembly

Adhesives And Applications

Smoothing Joins And Filling Chips

Modelling And Casting Missing Parts

Painting and Decoration




Inspection Recording And Pricing

Some restoration work to avoid:



If you really don't know much about home computers, just use paper, pen and pencil, but do get a digital camera, and put your photos in a cheap album, but read on anyway.

Give the item a serial (job) number. This number may then be used to identify worksheets, photographs, temporary packaging etc.,

To avoid confusion with other numbers, which may part if the work piece's provenance, prefix the number with your initials. To ensure that any sorted lists come out of the computer in numerical order, use 4 digits for the number (or 5 if you are really ambitious!) - so my item number 13 was 'jm0013' which appears on a sorted list before 'jm0100'. ('jm100' would come before 'jm13')

(This regular format is also convenient on your PC for renaming photographs, which come out of the camera as e.g. “IMG_2345.jpg” - a set of these is easily converted to your own format using the utility “Better File Rename” - see: http://www.publicspace.net/windows/BetterFileRename/download.html)

If it is not going into work right away, apply the serial number to the the base of the workpiece, in pencil, on a small self-adhesive label. (do not use ball pen or any other ink, which can get to places where it's not wanted !) The workpiece may then be wrapped up, and the wrapper marked with the serial number, and stored in a safe place till you're ready. Any broken pieces may be stored with it, e.g. in a freezer bag which is also marked with the serial number.

The serial number sometimes also turns in handy in identifying items brought to you, which you have restored on previous occasions! (people rarely bother to remove the label)

Photograph it, both for identification and future reference. I can hardly imagine how restorers managed without a photographic catalogue in the old days!. Using your PC, you can print a worksheet with a thumbnail photo of the item, and generate a catalogue page of thumbnails with serial number and customer's name. Rename the photograph with your serial number; if you are taking more than one, give the serial number to the principal photograph, and subsidiary photos supplemented with _1, _2, _ 3.... e.g.: jm1234.jpg, jm1234_1.jpg, jm1234_2.jpg, etc.

I use my Work Cabinet, (which has good lighting!) with a background of mid grey cardboard ruled into 1 inch squares, to give an idea of scale – because you want to fill the photo with your workpiece, and it isn't easy to tell what size it is otherwise!







My camera is a relatively inexpensive compact camera, (Canon IXUS 170) capable of 20Mb resolution and of taking very close detail shots. It's handy to have a cheap tripod - you can get one for a few pounds on E-bay. Load the pictures into your PC and edit them using the excellent free photo editor Irfanview: http://download.cnet.com/IrfanView/ Use the photo editor to make suitable thumbnail reductions for your worksheets and catalogue sheets: a resize to width of 310 pixels is handy, and save the reduced photo as e.g. “jm1234x.jpg”

Record the customer's contact details in a six-line text file, to fit into a worksheet:




Antique Dealers and major customers (e.g. collectors) may be prefixed with an underscore e.g. “_Mr Allen Sundrie.txt” so that they are automatically sorted to the top of the list.

Keep all these in a folder called “Addresses”

The worksheet I have used for several years now is a spreadsheet under Open Office 4.1.2 on Windows 10, which contains calculations giving average sort of prices for the work to be done, and prints out on an A4 sheet.

Have a look at the spreadsheets on my Dropbox, and do something similar on paper if you like, using scissors and glue to cut and paste, like I did till I was sure what I wanted, and just how to get it! Click on this link: Dropbox Restoration documents

The .pdf and .jpg files are examples you can download, and print out, to see what the paperwork looks like and copy it if you want!

The worksheet (a.k.a estimate sheet)

e008.pdf is a blank printed worksheet. Print this out for your own use to get the general idea!

e1500.pdf is an example of the printed worksheet for job number 1500, with notes, photograph, customer details, and a worked-out cost estimate.

The live worksheets are e008.ods and e1500.ods, which run under Open Office Spreadsheets (the free office suite; saving you a lot of money on Microsoft Office; the two are compatible so it will probably run OK under MS Office if you have it already) All they do is the multiplication and additions I have described.

The catalogue sheet is also an A4 print containing spaces for 24 thumbnail photos, with their job numbers and customer names:

A handy trick – say you have printed out your latest additions to the catalogue, and it looks like the .pdf file above, with 7 spaces occupied. Another customer comes along with two jobs, 1721 and 1722. You don't need to print out a whole new sheet! Just fill the eighth and ninth spaces, and print those on top the existing paper sheet.



The Timetable: One of the problems you will have if you are successful is a backlog of work to be done, and customers wanting to know when they will get it!

Note that spreadsheet this produces only errors if there are no corresponding worksheets! (#REF)

Column A is a list of the serial numbers of jobs to be done You set this up manually. Default calculation is An = A(n-1)+1, where n is the row number. Clearly you need to arrange it to contain only jobs not yet done, and put urgent jobs at the top.

Column B uses the serial number to read the value (price) for the work to be done, from the corresponding worksheet.

Column C gives the cumulative total value of work to be done. Nice to know this.

Column D converts the value of each job into days of work using the factor of £ per day shown in H2 - £20 per day in this case (I was doing only a couple of hours a day at £10/hour at this time; adjust this parameter to suit yourself!)

Column E Row 6 adds the start date set in H5 (in day number format) to the number of days in D6

Subsequent rows read the date from the previous row in Column H

Column F gives the weekday number of E (Sunday = 1, Saturday = 7)

Column G is 2 if the day is Saturday or Sunday, 0 otherwise

Column H adds column G to column E to give the finishing date for each job

You need to adjust H manually to allow for holidays, for example H16 = E16+G16+5, to make a Christmas break.



ADVANCED LEVEL: if you have some experience of using spreadsheets and of software coding, you may find this section useful.

APPS for producing thumbnail pictures, worksheets and catalogue sheets: There's still quite a lot of boring repetitive time-consuming work to be done in preparing these things with a PC! Especially if somebody comes along with half-a-dozen or more items.

Winbatch” is a top-level language which emulates an operator working on a PC keyboard doing repetitive tasks, such as assembling bits of data, pictures etc., into another format or application. Winbatch scripts are text files, with the suffix .wbt .

[Note: if you know the language, you might prefer to re-program these apps with Python]

So I developed software to automate these jobs, using Winbatch under Windows 7 or 10 and Open Office 4.1.2 , and with Irfanview as a picture editor. The Winbatch files are the two .txt files which you can find in my Dropbox. To use these you first need Winbatch which costs $99.95, but you can get an evaluation copy for 21 days.

Estimates.wbt is especially useful when you get two or more items from one customer. Get the photographs in the photograph directory with their new names, then run the program: select the customer name from scrolling list, and the first and last job numbers. The blank worksheets are then produced. The thumbnail pictures are saved in a sub-folder called “/Reduced Files”

Thumbprint.wbt will only work if the .ods estimates (worksheet) files exist! Tell it how many items are already on the catalogue paper, and it will start at first blank space with the job number you give it, and go on till the all existing worksheets are processed, or the page is full, whichever happens first. It doesn't print till you give it the order, just in case. When closing the thumbprint.ods file, remember to discard changes, so that you have a blank sheet to start with next time! (It's a good idea to keep a blank copy of the file.)


Dismantling

A lot of the stuff you get in will have been stuck together by amateurs, e.g. the owner's husband, with unfortunate results. Other items, especially those from the antique trade, will have been restored previously; this is not always so obvious.

Dismantling with Boiling Water.

Soaking overnight – not pottery!

Dismantling with Paint Stripper

Odd adhesives and fillers

Some folk will use anything which comes to hand to stick things together! Mostly they wash out – but some need special treatment:

Removing staples


Washing:

Practically everything you get in needs washed before any repair work is done. Ornaments sitting out in the open for a long time can get amazingly filthy.

For deep vases and flasks, a bottle brush is helpful:




Dirty Cracks - a Textile Cleaning gun


A great instrument to clean linear cracks which are resistant to washing and bleaching, especially in porcelain, bone china, or stoneware.. Don't use it on low-fired terracotta, or pottery with a crazed glaze; it can tear bits out. Keep your fingers out of the jet for the same reason!

Use warm rather than cold water. The addition of a few percent of a cleaning detergent such as Flash, is helpful; afterwards this, spray with plain water to rinse out any detergent remaining.

[Available on E-bay, about £50.]

Firing crack: Antique items will sometimes have firing cracks which often have black marks adjacent to a flaw in the glaze caused in manufacture. These cannot be cleaned, and should be discussed with the customer - whether to leave it or cover it up.






Bleaching

If washing doesn't clean it, bleaching may be needed particularly for items with dirty cracks; or antique table- or kitchen-ware with a crazed glaze, through which the pottery underneath has got stained.

Peroxide bleaching:

    It is not practical to immerse workpieces in a peroxide solution, because of the expense!

    Peroxide decomposes (to water and oxygen) in a few days, once it is activated, so the bleaching liquid must be made up just before application.

This recipe has a double effect. The peroxide solution is thickened up with fumed silica to make a paste (similar in consistency to wallpaper ceiling paste) which is applied to the stained area, in the same way, but more intimately, as paper or textile 'poultices' recommended by others. The peroxide can then penetrate any porosity or cracks to bleach stains. Other stains which are not bleached but which may be water-soluble wick out when the paste dries, in the same way as Laponite RD is used (ref. Lesley Acton), but when it dries out it is much more easily removed!



Kit: Average size glass or plastic beaker

Spatula or lollipop stick; and a cocktail or other small stick.

Plastic brush – the brushes in ladies' hair-tinting kits are ideal, about an inch wide and narrow across.

Plastic pipette

Plastic box with cover large enough to hold workpiece

KITCHEN GLOVES, EYE PROTECTION, apron etc.



Materials: 30 volume (9%) hydrogen peroxide. [ Salon Services (a.k.a Sally's) Liquid Peroxide 1 litre- excellent product and value ]

Household ammonia [ HomeBase, or some chemists]

Dishwashing liquid [ Fairy or similar]

Fumed Silica, filling grade [ CabOsil, E-bay]



Recipe: Pour a small amount of peroxide into the beaker.

Use the pipette to add a few drops of ammonia. If you have added enough, the peroxide will go a little yellow, if it's Sally's brand anyway. If in doubt, put the top back on the ammonia bottle, and carefully sniff the beaker; there should be a slight whiff of ammonia if you've added enough. The peroxide is now activated!

Add a tiny drop of Fairy liquid on the end of a cocktail stick and stir.

Add about 3 times the volume of CabOsil, and stir in with the spatula. Adjust thickness if needed, to make a paste which is easy to spread, but will not run off a vertical surface.



Procedure: Use the spatula and brush to apply to the stained areas, or along the stained cracks, on all accessible parts of the workpiece.




Put the coated workpiece into the plastic box, - being careful not to wipe off the paste.

PUT THE LID ON THE BOX, and leave overnight at least.

REMOVE THE LID, but do not touch the workpiece! Leave it there to dry.

When it's dry enough, the silica will fall off, often taking some staining with it. Put on your gloves, goggles etc., (the peroxide is probably still active!) and brush off the remainder. Rinse well with cold water, dry with a drying cloth, and leave overnight to dry out completely,

If stain is not removed, dish-wash again, and repeat bleaching.

If stain is still there after 3rd peroxide and dish-wash, go to the next stage.



Health and Safety: See precautions on materials containers! Ammonia fume is irritating to breathe in! Activated peroxide will sting and bleach your skin – wash it off as quickly as possible!

A dust mask is a good idea when working with fumed silica.



Phosphoric acid bleaching:

This is specific for rust stains, which are not removed by peroxide bleaching, are easily recognised by their rusty colour, and are often found on the rims of plates which have been hung up in steel wire holders.

Phosphoric acid comes at 85% and 45% strength in 5lt. plastic jerry cans, (E-bay) which will last you a lifetime or two.

Recipe: Take about 100-200 ml, water it down to 30% and add CabOSil (see Peroxide above) to make a paste as for peroxide. You can keep this for ready use in a plastic container as it is perfectly stable and not volatile.

Alternatively you could try a rust remover gel (same thing, search Google) but check to make sure it is not coloured - this could stain your workpiece.

Apply it to the affected area and allow it to dry out, then rinse off.

Health and Safety: gloves and eye protection. If you get it on you skin, wash it off. It is quite a weak acid , comparable to vinegar, and not at all toxic.



Chlorine Bleaching:

If all else fails an acid hypochlorite bleaching process may be used. It is inexpensive but it is dangerous and very slow; but it sometimes works when all else has failed.

I have found this to be of use only for antique kitchen- and tableware which has been grossly stained in use, on a crazed glaze, such as jugs, drinking vessels, and carving dishes, and which have not responded to other means of cleaning. In such cases, the stain has penetrated deep under the glaze, and sometimes migrated to parts where the glaze is sound. This means that the bleaching agent needs to soak in through the crazing and penetrate to every part under the glaze.

I have used it, with the owner's consent, on a few irreplaceable antique and semi-archaeological items, now museum pieces. For health and safety reasons, I am not putting this one on the Web; if you think it could be of use, contact me by e-mail.



The Unbleachable Antique:

In the old days, they used candles a lot, and oil lamps, and these generated very fine soot which could penetrate worn or cracked glazes, and lodge in the bisque underneath. This caused a grey to black stain on ornaments, particularly those which hung on walls and above mantelpieces. The superficial soot is easily washed off (leaving a typical slight tide-mark) but there is no way I know to get rid of the deeper discolouration, which is embedded in the material. (Soot is also known as carbon black). All you can do is paint over it.




Principles of Assembly

Before you start assembling anything which is broken in more than two pieces, work out the order in which they are to be assembled, and check for any missing pieces. In fact this is the first thing you should do, so that your customer can hunt for any missing bits under the telly or sofa. (this has saved me trouble on several occasions, and saved my customers money) The other reason is to establish how the pieces fit together, and work out in what order to join them.

The 'pons asinorum' of this business is to be able to assemble several pieces is such a way that you don't get left with a bit that you can't fit in.

General principles are:

  1. Do a test assembly using masking tape. For cylindical objects (jugs, vases), put tape on the join both inside and outside the vessel, if possible. This will establish if any bits are missing, and their probable colour and shape. It will also show up any joins which might cause difficulty. Look for major break lines.

  1. Never make a join which will create an acute angle (less than a right angle) between the joined pieces, into which you will need to fit another piece. Always aim to leave an obtuse angle. It may sometimes be necessary to fit 3 pieces together at once, to avoid this pitfall.


  2. Think two or three joins ahead. Try fitting in the next pieces, before you join the current piece.

  3. For round and especially globular items (teapots, vases, jugs) it's often possible to find, from the test assembly, a major break line of obtuse breaks passing right round the body, and through the point of impact, (which may sometimes be identifiable as a hole) In this case, consider making this line the final join, and assemble the two sections independently first.

  4. If there is a hole or a missing piece in a vase or pot with a narrow neck, make sure that the hole is filled while you can get at it from the inside! - if the final join includes the hole, fill in for each part well enough to complete from the outside.




You will hardly ever get a perfect join where the two sides match precisely along the whole length; I reckon about 1% of the time, maybe more on really small things.

There are five possible reasons for this:

  1. In nearly all cases, one side of the break is splintered, with flakes off the glaze and other small pieces lost entirely. This happens along the side of the break which has been compressed during fracture – usually the outside of a vessel.

  1. In many cases, the join has 'sprung' . As I mentioned above, clay shrinks by about 30% during drying and firing, and this can result in cracks and flaws. But even if no cracks appear in manufacturing, there is often stress left in the finished item, like a compressed spring. When it gets broken or cracked, it breaks in such a way as to help to relieve this stress, and springs into a very slightly different shape. Put the pieces together again, and they don't quite fit. The misfit may be no more than 1/1000th of an inch, (25 microns) but it will show up as a clear line if lit from the side and can be felt in handling. Items with sharp corners, or square shapes are very subject to this, and it seems to me to be more prevalent in bone china than in porcelain or pottery. See under Tacking with superglue on how to deal with a sprung join.

  1. The work-piece has be badly joined by previous repairers, causing damage to the edges.

  2. You have made a bad join regardless!

  3. Two or more of the above.



In what follows, I will sometimes use the word 'glue' when I mean 'adhesive' because it is shorter and easier to read and especially to type. I am not suggesting that you should use “an impure gelatin obtained by boiling animal refuse” - to quote my dictionary. So long as you know what I mean.

How bad joins are made on well-fitting breaks:

It follows that the ideal adhesive:

-but it is yet to be invented.

Different materials need different adhesives:

For adhesives, we divide ceramics into two types:

They need to be treated differently.

If in doubt which type your workpiece is, use a pipette to apply a drop of acetone to the clean broken surface. If it soaks in in less than 15 seconds, it's porous. If it takes 20 seconds or more (it will evaporate eventually!) it's not porous.

Thin liquid adhesives like Araldite 2020 and thin superglues are desirable because they make a very close join – but on porous ceramics they soak into the material away from the join you have just made, which makes a very weak join, because it has very little to hold it together. 2020 is not as thin as acetone of course, but it is slow setting and has hours rather than seconds to soak away.

The other thing that can happen on a porous ceramic with 2020, is that the thin liquid can cause a dark stain on each side of the join, in the same way as a wet fabric looks darker than a dry fabric. Paraloid does not do this. (This is of no importance if the join is to be painted over afterwards, of course. )

Means of support:

Unless you are using a 'instant' glue which sets while you hold it, your join needs to stay steady while the glue sets, which may be overnight.

Things to avoid are:



The final consideration, before I go on to details, is

How do you know if a join is strong enough? The answer is simply:

If it survives your subsequent handling, it is strong enough.




Adhesives And Applications

Epoxy Resins are the most generally useful.

These are two-part adhesives which, when mixed, set (usually) at room temperature to give a tough, insoluble plastic. The join is generally as strong as the original ceramic at room temperature. There are three types to consider:

1. The traditional slow-setting two-tube Araldite Standard (there are several other brands) is a thick liquid which makes a tough and very durable join.

Because of its viscosity, it is hard to make a really close join, and because of its slow setting, there are often problems in holding the join together while it sets. You need to squeeze the join together to make it tidy, and this expresses a bead of adhesive which needs to be removed after setting. It is resistant to heat, and doesn't need heat to cure it fully, which happens overnight at room temperature

This comes either in a pair of toothpaste-type tubes, or in a double syringe. I prefer the toothpaste tubes; I find it easier to dispense the small quantities usually needed, but I don't use this very much, except to prepare surfaces for Milliput filling (see below)

Sources: most hardware stores; craft shops, model and hobby shops, E-Bay



How to use Araldite Standard:



2. The 'instant' type, notably Araldite Instant 90 sec. This is very useful for certain jobs especially on porous ceramics, but has limitations.

Advantages are:

Speed - but allow 5 minutes not 90 seconds. Unless it's a very hot day.

It flows easily under pressure. This means that you can squeeze two pieces of porous ceramic together, and it will make a tidier join than 'Standard' and penetrate into the material far enough to get a good grip.

The bead can be removed much more easily than 'Standard' by running a modelling knife along the join, immediately after setting.



Disadvantages are:

Holding while setting -If it is necessary to hold the joining pieces together, with one in each hand, I find it very difficult to hold absolutely steady for 5 minutes, while exerting a gentle pressure. Any movement, especially about the 3 minute mark, results in a weak join.

It has limited resistance to heat. I have carried out tests (following some unexpected failures), and find that after heating for 30 minutes at 80C, and allowing to cool, the joins come apart easily. I use a method of painting which requires a cure at 70C at least (see below), which rules this adhesive out for most of my jobs.

Sources: most hardware stores; craft shops, model and hobby shops, E-Bay

How to use Araldite Instant:

There are many other types of Araldite and other brands of 'instant epoxy' on the market which I have not tested, and I would urge you to try them and see what may best suit the job. It is worth experimenting with plain ceramic tiles cut into about 1” strips with a tile cutter. Break these strips in two, and join them with your test adhesive. Two simple tests are: to bend a join till it breaks, or strike it on the edge of a hard surface. The ceramic should break before the adhesive.



3. The glass adhesives: Araldite 2020 and Hyxtal NYL-1

These were not developed for ceramics at all, but have found application with restorers.

Both are clear, colourless and non-yellowing, which is of course a prime requirement for glass,



I will deal with Hyxtal first since I don't use it....



Araldite 2020 is my choice for most work.

It is quite a thin liquid, and comes in two bottles, at about £50 for 500g.

Sources: widely available on E-Bay etc.

If a thicker adhesive is needed, you add fumed silica (filling grade) to make it as thick as you like; the silica also makes it sticky, which may help to hold a join in position and sets to make an extremely tough translucent solid, which can (in a few cases) be used as a filler.

How to use Araldite 2020:

Drops of:

A B

3 1 = 100:33

5 2 = 100:40 or 6 2

8 3 = 100:37.5

12 4 = 100:33

I define:

Application:

Leave the join overnight to set well enough for handling. A peculiarity of 2020 is that it cures much more slowly on exposed surfaces (it is of little use as a glaze). So you can often then scrape off the excess with a modelling knife, and clean off remaining smudges with methylated spirit, which dissolves it at this stage. To harden it completely, it is best cured in an oven for 45 minutes at 70 - 80C, but you can leave this till convenient.

Alternative two-stage (consolidation) application for porous materials:

I find this method gives about the toughest joins of any; in tests I carried out on bending stress and impact, the material always broke instead of any part of the join. Disadvantages are: two stage process; join tends to be a little less precise; and the thin 2020 may leave a watermark under the glaze.



Adding pigment to a 2020 mix:

As mentioned above (Principles of Assembly) there is always that little gap, where the adhesive lies, between the two joined pieces. Since 2020 is transparent, incident light is lost down the gap, and the join appears as dark line. A very careful addition of a tiny amount of white pigment (titanium white) plus perhaps an even smaller amount of yellow ochre, can minimize this effect,on the usual sort of white ground, with three caveats: (1) too much pigment will leave a white line instead (2) you may get a white line anyway across other decorative colours (3) If the glaze is especially thick, you may produce the effect of having a tiny white wall in the glaze, which is all the more visible of having a shadow on one side. It is a trial and error process, but depending on the application, it may give better results, on a very clean break, than air-brushing substantial areas.



Tacking with superglue for joining with 2020:

Always aim to get rims and edges (e.g. on plates, vases or jugs) in the best alignment – any misalignment on a rim is much more easily seen, and felt, than in the body of the workpiece.

On porcelain and other non-porous material, use thin cyanoacrylate superglue to tack the edges in place, while holding them in together so as to eliminate any springing.

On porous material e.g. bisque or creamware with a thin glaze, consolidate the whole join as follows:

Complete the join by filling with Araldite 2020 Thin mix, drying, cleaning the surface, and curing. See also Example 2 for details of joining and following treatments.



If it is not possible to eliminate springing completely , you can abrade mismatched edges down with emery paper, or at least soften the sharp edges . The restorer's general rule doing only work which can be reversed (other than cleaning!) has to be applied or ignored in the context of your customer's requirements; just don't do this on museum pieces.



Cyanoacrylates (Superglue)

have limited direct application because of their poor resistance to impact, - a join with cyanoacrylate can be practically invisible on a good porcelain like Lladro but do not be tempted : it is extremely brittle - but they are indispensable for very fine close work in conjunction with Araldite 2020.

They are clear and colourless and cure in matter of seconds, especially to your skin. Always use disposable gloves (the blue nitrile sort is best; these are available from hairdressers' suppliers, pick them up with the peroxide) and keep some acetone handy. Acetone will dissolve the adhesive if you get to it fairly quickly, after making a crooked join.

Get the very thinnest grade, to make the best joins. One brand is very much like another, but for dispensing tiny quantities at a time, a small plastic bottle, with a screw top and/or a fine removable nozzle is preferable to a squeezy tube. It's a good idea to keep small light bottles like this in a heavy glass jar or beaker, so that they don't get knocked over accidentally, to make a sticky and expensive mess....






How to use cyanoacrylate superglue: It is useful only on non-porous materials; it will soak into porous items and disappear.

To 'tack' a join, to be filled with Araldite 2020 – see Example 2 Chinese porcelain plate

To join many pieces of a complicated break, which will be held together more firmly by other means – See Examples 3 & 4.



Solvent Adhesives (such as UHU All-Purpose Glue) are not used for this work,

..... except for Paraloid B-72 ( https://en.wikipedia.org/wiki/Paraloid_B-72 , available on E-Bay, Amazon, etc) which is approved for certain museum work. It is ethyl methacrylate, which dissolves in acetone, and is a poor adhesive (in my opinion), but it does not yellow, is easy to remove, and does not discolour earthenware under the glaze. If the finished item is just going to sit in a glass case, sure the adhesion doesn't need to be great.

It comes as small chips, which you dissolve in acetone to make whatever thickness you like; it dries as the acetone evaporates, and it has some applications for porous ceramics.

How to mix and use it:

On porous materials, you need to use a two-stage process and two glue recipes, as follows:

  1. Apply a thin (5g Paraloid chips : 100ml Acetone) solution to both sides of the join. This will soak in well, without causing a watermark under the glaze. Leave overnight to dry out.

  2. Weigh out 25g Paraloid and add a level teaspoonful (0.15g) of Fumed Silica (Filling Grade) into a small jam jar with a good screw top. Add 50g (about 65 ml) acetone, and stir a bit. The Paraloid goes all sticky and settles to the bottom. It will not dissolve quickly so screw the top on and leave it for a couple of hours. After this time it looks as if it has dissolved, and so it has; but it is much thicker at the bottom! So stir it up with a palette knife or similar, and it will probably be OK when you check it in another couple of hours. If it's too thin for your job, leave the lid off and stir occasionally, quite a lot of acetone will evaporate off in a working day.

  3. Decide exactly how you are going to bring the two parts of the join together, and to hold it steady while it sets.

  4. You may find it best to use disposable gloves.

  5. Use an Ultrabrush to apply the thick glue to one of the surfaces

  6. Press the two parts together, gently but firmly, to make as close a join as possible, and set up the assembly in such a way that it will not move while the glue hardens.

  7. Leave it to set; all the acetone needs time to evaporate completely. I suggest at least 48 hours in a warm place.

See also Example 4.

Paraloid solution needs to be kept in a very well sealed container, because acetone is very volatile, and if you aren't using it very much, it will evaporate, so your thick mix become solid. On the other hand, if you have a very well sealed container, any glue around the top will seal it even better, so you can't get it open at all. I haven't quite solved this problem.... maybe a polypropylene jar would be right.



No-Nos :

Do not attempt to use fillers like plaster, Polyfilla or Milliput as adhesives, nor any water-based glues, nor any latex adhesives like Copydex. They are not good for this job. They are good for their own purposes.

Refuse work where the adhesive in cumulative breaks will push the final join well out of alignment. If you attempt to do the impossible, you will do it very badly.(Sancho Panza's law)




Smoothing Joins And Filling Chips

Well, good work folks, it's all in one piece again! Let's paint it …. no, wait, it looks a bit rough here and there.... indeed it does.

Smoothing and filling is needed on about 90% of the work. I define a chip as small piece no more than about 2 square centimetres, broken off, usually from an edge, which would have pretty much the same shape as the surrounding material - therefore excluding things like teapot spouts, figurine feet and fingers, and so forth, which I will tell you about in Modelling and casting missing parts



The only filling material I have used on ceramics for many years is Milliput Superfine White. This is a two-part epoxy putty, which can be worked and shaped very like Plasticine, and which sets to a hard resin which may be carved or sandpapered to shape. It is widely available in hardware and craft shops, and on-line.

I use it in its native putty form to build up chipped areas, or for more elaborate rebuilding or modelling on a small scale.

I use it in a liquid form (Milliput Dressing ) to put a dressing on practically all joins. This has the consistency of cream and is very easy to apply. You don't buy it in liquid form, you have to make it up according to a method I have developed, which I describe in Milliput Dressing



I will deal first with the normal application of Milliput as a putty.

It comes, as illustrated, in two 2 oz. Sticks. One is off-white in a clear wrapper, and one a light yellow in a blue wrapper, each with the consistency of Plasticine. These have to be mixed in equal amounts before use.

Once mixed, it has working time of an hour or more. It sets hard overnight, and when set it is tough rather than brittle, with working properties of a good hardwood, without the bother of a grain. (The makers' description of it as 'rock hard' is not strictly accurate – let us rather say it is just right for its purpose!) .

It has good resistance to heat, water and most solvents; it softens only under paint stripper. The fillers have a very fine texture; there is no perceptible graininess. I have no information about what the fillers are, but I would be surprised if titanium dioxide (titanium white) and china clay had no part in it.

How to mix it:

The instructions are a bit vague; I quote:

“Blend equal amounts of each stick by rolling or kneading until the colour is uniform and free from streaks.” - this is on the box: there is more information inside on in the instruction leaflet, which suggests (in short) kneading and rolling for a minimum 6 minutes. The problem with this is, that the two colours are not very far apart anyway, so it's hard to tell from that if it's well mixed.

To be absolutely sure that I always got a good mix I developed and used the following procedure, which is also rather quicker:

  1. Use a disposable working surface of a light card or heavy paper, and wear close-fitting disposable gloves to be on the safe side..

  2. Take equal quantities of ½ to 2 grams of each colour – ½ g. is about the size of a small pea, 2 g about a broad bean – and roll each into a ball. As with most other epoxies, the exact quantity is not critical - there is no need to weigh them out – just be sure that they look equal in size.

  3. Press the two pieces together into a disc and tear the disc into two pieces.

  4. Press one piece on top of the other, and turn it through a right angle clockwise (or anti-clockwise, but keep rotating in the same direction) and tear it in two again.

  5. Repeat instruction 4 twelve times, and roll the putty into a ball on the working surface, then squeeze it into a disc and go to instruction 4 twice more - a total of three times.

You will have now executed what mathematicians call “the baker's transform” thirty-six times, and each time you double the number of layers, starting with 2, 4, 8, 16, 32...... to 236, which is about seventy thousand million, if each layer lay exactly on top of the one below. Bits squeeze in all directions of course, so we stop after 12 and roll the putty into a ball before continuing, so that bits on the edge don't get totally left out.

This has always given me consistent results and takes only two to three minutes.

Roll out the final ball to a thin roll to suit the job in hand.

You will note that I suggest mixing quite small amounts. Experience has convinced me that in estimating how much putty you will need to fill one or more chips you always make up twice as much as you need, even after you have allowed for that fact! So bear this in mind to reduce wastage..

Milliput Dressing

This is an invention of my own, arising from a problem.

Milliput can be used very effectively to fill in flaws along a join, caused by splintering and chipping at the time of fracture, or to cover slight misalignments, or the accidental absence of adhesive at some point. When the putty has set, it can easily be rubbed down to give nice flat surface suitable for painting.

The problem is, getting the Milliput into the join. It can be lubricated with water, or thinned with methylated spirit, and pushed where you want it with a spatula or dental tools, but the procedure is difficult and messy and it is too easy to miss bits out, because it is not smooth. It would be so much easier if we could thin it in some way.....mixed Milliput appears to dissolve in a 50:50 mixture of methylated spirit and acetone, but the polymerisation has started as soon as the two components are mixed, and you can't get it to dissolve fast enough, so the result is a mess.

I experimented with dissolving the two components separately, and found that:

Both solutions are stable indefinitely - I have been using the same two screw-top bottles for about 10 years, just putting in more of the mixture as needed, and waiting till the solid dissolves before use.

Make them up as follows:

NOTE:

  1. if you are using a PROSCALE, protect the platform with a piece of polythene or similar – the plastic the scale is made from dissolves in acetone! This results in a slight inaccuracy which is of no importance.

  2. When the contents of a bottle get low, there is no need to clean it out or take a new one. Just add more of the same. I used the same two bottles for years.

Application: (dressing)

The mixture has a consistency and flow like lightly whipped cream, and will stay where it is put, if you don't put on too much.

The mixture dries out quite quickly through evaporation during application, and may start to get too thick if you have a lot of joins to fill or build up – thin it if necessary with an equal mix of acetone:meths, and use this solvent mix for any cleaning.



Filling chips with Milliput putty and dressing.

Milliput has limited adhesive properties, and if you are filling a shallow mussel-shell shaped sort of chip with a clean surface, it is generally OK just to press a suitably-sized lump of Milliput into it, and remove any surplus. But in cases where the area available for adhesion is smaller than the area to be restored (for example a plate with broken rim) I have found it to be necessary to prepare the surface of the break with an epoxy adhesive first.

Use Araldite Standard or slightly thickened 2020 for this job, apply a thin smear only to the clean surface of the break, and leave overnight at least; this can often be done conveniently when you are making joins.

Mix the Milliput as described above, and press it well into the chipped area. Cut off excess with a modelling knife or an artists' small palette knife, shape it as required with Small hand tools .

The putty is of course sticky, and the makers recommend wetting it with water to assist modelling – it does not dissolve in water, but is lubricated by it. If you need to remove some misplaced putty, methylated spirit , or a mix of equal parts of meths and acetone, will dissolve it.

I have found that saliva is a smoother lubricant than water: spit some into a small dish, do NOT be tempted to lick anything!

Don't try to make an exact filling; always overfill slightly on to the adjacent good surface so that the edges of the chip can be smoothed down flush.

Leave overnight to set. Depending on temperature, the filling may still be a bit to soft for good modelling; if in doubt, cure it at 70C for ½ hour.

Trimming to shape.

A modelling knife ( see Small hand tools) can be used for initial rough trimming.

Glasspaper is used to smooth down fillings, without scratching the glaze. Use only the glasspaper specified below! The usual stuff you pick up in a hardware store will scratch the glaze, in a way which is very difficult to correct!

Don't use metal files; they clog up and can also cause scratches.

Where you might use a file, wrap some glasspaper round a flat stick, such as a lollipop stick or a coffee stirring stick (widely available f.o.c.) or if you need a round form, a piece of stiff wire; I use two pieces, one cut from a wire coat-hanger, and a thicker one from fencing wire. For very small detailed work, cut a postage-stamp sized piece of fine glasspaper and roll it up tightly by itself.

For a working surface when smoothing down, use a few layers of an old towel to distribute the pressure on the workpiece and to keep it steady.

Very small chips can sometimes be smoothed down in a single operation, but larger ones generally need two or more stages.

Stage 1: Fill the chip with Milliput, and when set, use #100 or #120 grade glass paper to smooth away the excess to the extent that you can see where the exact edge of the chip is, without undercutting it. The Milliput is sufficiently translucent as you get really close, and it smooths down to the ceramic surface without breaking away.

You can now run a finger over the filling and feel how far it is away from being perfectly smooth with the surrounding ceramic, and if any edges feel prominent.

Another way of getting an idea of how accurate the filling is, is to wet the surface (saliva will do the job well, but don't be tempted to lick it) and examine it under a striplight, which may for convenience be installed in your work cabinet. Look for the reflection off the shiny surface (called the specular reflection) and turn the workpiece this way and that; any unevenness will show up clearly.

If has got undercut, or the ceramic edges are prominent, go to stage 2. Otherwise, continue rubbing down, with the next finest grade or a Micromesh Polishing cloth, until the surface is precisely even.

Stage 2: Fill any flaws, gaps, bubbles in the material or undercut areas with a light application of Milliput dressing, as described above. Leave overnight and cure if required. Rub down with the finer glasspapers or polishing cloths. Inspect the result and repeat as needed.



Smoothing joins with Milliput dressing : recommended for all joins which are to be painted!

After a join has been set, and cured if necessary, it is important to smooth it out before painting. No more than about one percent of all joins are so good that nothing more needs to be done to them; as I noted above there is usually a tiny but conspicuous gap, and very often there is some splintering along the edges, arising from shattering on impact or from careless handling afterwards.

A further hazard – not obvious even on close examination – is that there are places in the joint which are not wholly filled with adhesive. A problem with this arises during painting with an airbrush, particularly on porous ceramics. The paint is driven into the gap, and onwards, leaving a very conspicuous little hole behind it, which never fills up, or reappears shortly after you reckon that it has filled. At this point, you have to abandon your painting and preparation, clean it all off, and go back to the Milliput dressing stage. (it's no good leaving the paint to dry and trying again, either)

You really need to experience this one for yourself to understand how infuriating and time wasting this is.

Bitter experience has taught me to ensure that each join is filled for the entire length which has to be painted, which is usually all of it on both sides. Milliput dressing makes this quick and easy.



Mismatched joins:

Where the two sides are a join are not perfectly level with each other, because of springing or ordinary inaccuracy, Milliput dressing will help to cover the defect by providing a ramp between the two levels instead of a much more visible step. There still tends to be a sharp line at the higher end, which can mar the appearance. Provided the workpiece is suitable (not, for example, a museum piece) this edge may be abraded down with emery paper, 240 to 320 grade. This does not seem to undercut the Milliput filling. Note that you are making an irreversible change to the workpiece! This is heresy!



Colouring Milliput dressing:

It is immediately obvious that white Milliput dressing makes a pretty good join a great deal more conspicuous than before; but if it needed painted anyway, it isn't really making any more work for you.

It is possible to colour the join with pigment powder, mixed into the dressing, but colour matching is difficult because you can't dry it out completely during matching, and in any case it has a matt finish which is usually wrong. I have come to the conclusion that it is generally not worth the extra time if you are going to paint it anyway, but sometimes collectors or museums may request 'no painting'. In which case, note that most “white” ground colours can be matched well enough with only yellow ochre and lamp black in the white dressing.



Some fillings other than Milliput:

Sylmasta A+B is also an epoxy putty. https://sylmasta.com/catalogue/

I found the filling coarse compared to Milliput; it could not be feathered down so well to an invisible filling on a chip or crack. But it is very tough and bonds well to metal; the last time I used it was to replace a missing foot on a Chinese porcelain umbrella stand, supported by a suitably bent piece of clothes-hanger wire grafted into the ceramic..

Polyfilla. Useful for repairing items made with plaster. Some pretty woman will plead with you some time, to fix their granny's plaster figurine, and you will give in. Milliput is too hard when you're trying to smooth it down on plaster. Use 'Multi Purpose Polyfilla' powder mix with water. If some modelling is needed, mix it with a lot of talc to make it less sticky.

Plaster. Restoration Plaster” - available in craft shops. Use this for mouldings, as I shall describe below. Do not attempt to fix plaster with it, since the original plaster sucks all the water out of the new mix, which then just crumbles.

DAS Air Drying Modelling Clay is an inexpensive and good substitute for Milliput where large areas or volumes are to be filled. It needs no mixing before use and may be softened with a little water. It needs a couple of days to set. It has a fibrous filling which gives it good strength but makes it unsuitable for fine detail, but it can be finished to a good surface with Milliput dressing.

Other uses of Milliput: it is suitable for repairing resin moulded ornaments and painted wooden items too.

Which brings us to our next topic:


Modelling and casting missing parts


Small missing pieces needing no extra support

- such as the ends of teapot spouts, jug spouts, and edges of plates, can usually be modelled directly in Milliput Superfine White

If there is any doubt about the cleanliness of the broken edge, such as old adhesives (after you have exhausted the cleaning processes! ) grind them down a little with your Mini-drill and a burr.

Prepare the broken edges with a thin smear of Araldite Standard or similar, and allow it to set before applying the Milliput.

Mix the Milliput, roll it out to a thin roll about the same diameter as the thickness of the ceramic, and cut a short length. Fit this round the break, press it on enough for it to stick, and trim off the ends. Apply another length on to the first, so as to make towards the desired shape, and continue with more until the shape has been roughed out in a series of little rolls, as sketched in below. Allow to set, Glass Paper towards the desired shape, and continue to the precise shape in stages using more Milliput or Milliput Dressing.

I have found this technique to be easier than attempting to apply the Milliput all in one piece. You can build up quite large items in this way, if you do it in stages, allowing the putty to set between stages.




Small missing pieces needing Extra support,

such as fingers on figurines, stems, leaves and petals on flowers, and suchlike.

The technique is to use Araldite 2020 Paste mix to attach a suitable piece of wire or foil to the break. The paste must be stiff enough to hold the wire in position while it sets. Be careful not to apply the paste beyond the break, because it sets to a very hard plastic which is harder than Milliput after setting, and therefore awkward to remove! Wipe off excess with methylated spirit if necessary.


You then have to cure the workpiece to ensure that the paste is set hard enough to withstand subsequent final shaping.


After this it is easy to apply Milliput from a small roll, and cure it again before shaping,

You can use the same technique with copper sheet, but instead of using Milliput putty, you may find it convenient to use Milliput Dressing to coat leaves (as on flowers and trees) and small flat surfaces.



Larger missing pieces needing Extra support, and perhaps some simple moulding and casting.

The principles are essentially the same as above, but it may be necessary to drill into the break to make a anchor for the supporting wire. If you do this, you can use Araldite Standard as the wire adhesive, because of the depth of the hole gives greatly improved anchorage. The rest of it follows on in the same way as above, if you can model the missing piece directly on the wire.

More often, you need to craft the missing piece as a separate job, either by modelling or moulding. In this case, if you need a supporting wire, do not attach it to the workpiece until the two parts are ready to be joined!

Proceed as follows:



Two simple methods for moulding and casting small parts (up to one or two cm,) which can be copied off other bits of the workpiece with one-part or open moulding. An open moulding is one which can be taken off the pattern piece and off the casting without cutting, with only a little amount of stretching, like you would take a glove off your hand, or with no stretching at all.

If some stretching will be needed to get the mould off, use Copydex and sesame seed (it needn't be sesame seed, any small regular particulate material will do!) to give the mould some rigidity.

Example: this was the technique I used to restore the Beleek Venus's middle finger, which you can see on the homepage of my old website, or in more detail on http://www.james-mccartney.co.uk/pics/Antique Irish/jm652_2x.jpg The middle finger was of course copied off the index finger.

If no stretching is required on the mould, or a simple impression is required, use Godiva Modelling Wax




Larger Simple Mouldings A frequent enough damage is a pot or vase with a large piece lost out of the rim: (jm1559)


When the rim is smooth, and too large to model directly, mould it with Dental Registration Wax as follows:




This rarely gives perfect results, but does produce a filling which has the right curvatures and fits the break pretty well, and can be filled and rubbed down as needed to achieve perfection. (It is much more difficult to make a silicone moulding for this sort of thing, if you think about it.) After this, harden the plaster surface with a light coating of Araldite 2020.


Full Moulding and Casting

When I was in this business I restored over 1700 items, but I have had to do this only half-a-dozen times. You must need to restore a pretty complicated piece, and have an equivalent piece to take a moulding off. This does not happen often. The most common requirement is probably a two-handled vase, urn, or loving-cup, with one handle lost.

Moulding and casting is a popular enough hobby, and there is plenty of literature and materials for it; I cannot claim to be an expert. There is a large quantity of advice on the subject on the web, including tutorials on YouTube, .pdf files of advice to download, and books on the subject on Amazon and your nearest library.

As regards moulding materials, I would recommend silicone rubber; I used Silicone Rubber for Casting and the release agent which goes with it. (see illustration)

I shall therefore limit my discussion to a particular example of this type, which could have been done no other way, with details of how I did it and what I used for the purpose – see Example 6 Two Beleek First Period Jardinières

This is a description of the principles and details of the moulding and casting in that example.

Before you start you need to consider four things:

  1. A suitable container for the moulding, which is cheap, disposable, easy to make, and no larger than necessary to hold the cast – with regard to the expensive silicone rubber! In this example, I used cardboard; for smaller items, you can often make a little pot out of Plasticine.

  2. How you are going to support the original within this container

  3. How you are going get the original out of the moulding, and (later) the casting(s)

  4. How you are going to fill the moulding with the casting material

Making the mould: For this job, I made a box out of cardboard held together with masking tape, and applied Vaseline as a release agent to the inside of the box, and the recommended silicone release agent to the bird.




The bird was supported on the base of the box with a piece of Plasticine stuck to its original wing (see picture on the right of the underside of the bird); this also serves to make a hole for pouring the plaster into the mould. The restored wing is uppermost.. You can also see a piece of Plasticine stuck round the (broken) front leg which would be difficult to fill anyway, but I also needed more material in this area to cater for the different mountings of the missing birds.

I worked out the amount of silicone needed from the dimensions of the box: the area of the base times the height of the bird in the box, ignoring the volume of the bird itself so as to have a bit over. I measured this into a disposable beaker and then added the catalyst at 1% (See Silicone Rubber for Casting ) to give a slow cure, and simply poured the liquid slowly into the box, ensuring that all parts were covered. Inspection of the dregs in the beaker showed that the silicone was set after 6 hours.

To get the original out of the mould you need to split the mould. You can either:

  1. pour the silicone in two stages, say up as far as the beak, then let that bit set, apply release agent and then pour the rest to complete the covering of the bird. This requires you to make up two lots of silicone, which is wasteful and a nuisance: but the mould comes out in the required two pieces OR

  2. This is what I did: mark the cardboard on the outside at a suitable cutting line ( vertically, opposite the beak), and then pour the mould in one operation. Then push a knife through the mark to make a cut on the mould, remove the box, and use a Stanley knife or other sharp knife to continue to split the mould, and remove the original. (Any such cutting should avoid previously restored parts, so as not to cut bits off them!)

  3. It may be sometimes helpful to cut the mould further into more than two pieces. In this particular case a third slice through the restored wing, which is lower during casting, would have been a help, because it was difficult to ensure that the plaster got into it properly, and once it was in, it was hard to get the cast wing out without breaking it.




This shows the open mould, and the two parts closed with a rubber band. In practice I used three rubber bands during casting. The mould is now inverted, so that the filling hole is at the top.

I made up about 40 mls of Restoration Plaster as instructed. For this particular job, before closing the mould, I filled the lower wing with plaster using a plastic pipette to avoid trapping air in it, and added a little more plaster to the lower mould; then closed the mould carefully, applied rubber bands, and carefully poured in more plaster through the filling hole, also using the pipette to ensure that the upper wing was filled.

I left the casting overnight and de-moulded it carefully. I cut away the plaster from the filling hole and shaped the wing correctly, and smoothed down the moulding lines (where the two parts of the mould joined). There were also two minor defects caused by air bubbles; these were easily filled with a little more plaster. I repeated the process: I needed three good birds; one was spoilt by air trapped in the tail, so I made four castings.

When I had 3 birds shaped to my satisfaction, I gave them all a brushed coat of Araldite 2020 (Thin mix), allowed this to dry overnight, and cured at 80C for 1 hour. The 2020 soaks into the plaster and makes a hard shell. I finally cleaned this down with methylated spirit to remove a slight tackiness.

Return to Example 6 - Painting and fitting the castings


PAINTING and DECORATION

Properties of paint

Colour mixing – an introduction

Paint Ranges for Ceramics

The Ground Shade

Ground shade painting

Airbrush Maintenance

Decoration

Paint Brush Decoration

Brush Application problems

Circular Lines

Tin Glaze Ware

Airbrush decoration and shading

Finger Painting

Final Inspection

I started this sort of work as a hobby in the early nineties, to have a complete mental change from the world of computers and communications at which I earned my living. I felt it restful to work at a technology in which all concepts did not have to be continually revised and updated! But progress is still made in adhesives and paints, if not every month or two, at least every decade or two. I did however stay with the types of paint I started with, and did not move on to acrylics.



Properties of paint:

Paint consists of two main parts:

The medium, which is a liquid of suitable consistency and little or no colour (not even white), which dries to a thin durable and generally transparent glossy layer. The medium defines the method of application and durability properties of the paint, and different media cannot usually be mixed together. The medium may be a liquid in itself, like linseed oil (the traditional oil paint medium) or may be a solid material dissolved in a solvent. The solvent, which is also used as a thinner, is sometimes called a base:

You can consider three types of medium:

Water-based, for example: water colours, gouache, distemper (glue in water – not used nowadays!)

Oil-based, for example: household gloss paints thinned with white spirit ; linseed oil, traditionally thinned with turpentine.

Emulsions, which are oil-based dispersed in water, for example: emulsion paints(!), acrylic paints, many cosmetics. Emulsions may be thinned and cleaned with water.

As a rule, paints with different media do not mix well together, as you will find if you try it; the result is generally an useless gunge. Emulsion paints have circumvented this rule by means of clever chemistry, (which would take much too long to explain) the idea being to reduce the amount of oil-compatible solvents which may be used, because these are are expensive, sometimes harmful to the environment and potentially to the painter.

(And while I'm on it, don't attempt to mix solvents, such as white spirit or xylene, with water, in an attempt to save money on cleaning brushes, palettes, etc. )

The pigment is a dry colouring matter, usually an insoluble finely-ground powder, which is mixed with a medium to produce paint. It sometimes a naturally-occurring mineral colour, such as iron oxide (ochre), but is just as likely to be synthetic. Apart from being highly coloured and chemically pretty inert, pigments, even those of similar colours, have often little or nothing in common with each other, chemically speaking. The inorganics – metal compounds – are the most durable, by and large. (For more information than you can possibly absorb, search for “inorganic pigments” and “organic pigments” in Wikipedia. “Organic” in this context does not mean it was produced from manure.

The paint may also contain a matting agent, which is not strictly speaking a pigment, but changes the appearance from gloss to matt.

The colour of the paint is determined by the pigment used; two or more pigments are often used to produce useful standard colours, where no single pigment will do the job - for example, emerald green will most often be produced with a mixture of a blue and a yellow pigment.

A range of paints is a set of paints of different pigments all using the same medium and solvent. The colours are selected to cover consumer requirements and different colours within the same range can be mixed together to produce different shades.

For our purposes, we need a clear glaze paint as well as colours; this is usually the medium without any pigment.

When we paint our houses we are used to being presented with a few hundred colours to choose from, in a variety of ranges. But all these colours are made up by mixing quite a small range of basic pigments, and you will have to learn to match the colours on your workpiece by mixing from as few as a dozen selected colours.

Colour mixing – an introduction:

It is helpful to think of colours as forming a circle. In the rainbow we have bright colours: Red – Orange – Yellow - Green – Blue – Violet, but there is a gap between violet and red, which may be filled with purple and magenta to complete a circle. There are no greys or browns or khakis in the rainbow. The following chart, which is cribbed from The Colour Index, (the several large volumes of which constitute the professional colourist's standard reference), will give you an idea how one colour blends into the next. This gives you a first approximation of the ideas of how to mix colours, and how to select a range of colours.

The bright colours are round the outside; the dull colours are further in.


As a rule, if you draw a straight line between two colours on the circular chart, it will give you an idea of what you will get if you mix two paints of those shades. You can mix two adjacent colours round the outside to get a bright shade in between, but mixing colours further apart will give duller colours; for example, yellow and grey will give you khaki; orange and grey will give you a brown! Further apart still, green and red will give you grey, but so will orange and blue, in the right proportions. You can also see that while you can mix bright colours to give you duller colours, you cannot mix dull colours to give you brighter colours.

It follows that, in order to have a reasonably small number of paints in a range, most of them must be as bright as possible, supplemented by black, opaque white and maybe a couple of browns..

The above chart is two-dimensional and refers to what colourists call a 'hue' There is another dimension, 'depth', which runs from pale colours to dark colours of the same hue: for example, pink is a pale red, beige is a pale brown, grey is a pale black. The next illustration shows the effect of adding white to the range of Humbrol colours which I have used for many years. The top row is the paint as it comes, the middle row is one part of coloured paint to 3 parts of white, and the bottom row 1 part of coloured to 15 parts of white.(or 1 part of the middle row to 3 parts of white).




You see at once that the I have chosen seven bright colours which you can see round the perimeter of the circle, plus three dull colours which are useful for mixing with bright colours to get duller shades. Black itself is a commonly used colour. This range of only 10 paints, plus white and clear glaze, is both necessary and sufficient for most decorative purposes. (You will notice that I have two very similar blues. The one on the right is used only for a few special purposes.)

At this point, if you are confused by the colours in the two charts above, please go back to BEFORE YOU BEGIN and take note of the first point - it is possible that you may have a problem with your colour vision.

I produced the above illustration by painting Humbrol colours on a white tile with a small brush. The dilution with white is not precise; I simply added one drop of colour to three of white, off a cocktail stick.

The fact is that these paints are not particularly well standardised, as they would have to be for industry; if you have two pots of the same paint, you may find one is noticeably stronger than the other. But the need for accurate shade continuity between different workpieces does not really arise, as it would, for example between a car door and the car body, or between jacket and trousers of a suit.

You will find it helpful to make up tiles like this, to have something to guide your eye when you are mixing colours for decoration, and it is a useful introduction to actually applying the nice new pots of paint when you get them.



Paint Ranges for Ceramics:

(Follow the hyperlinks for suggested ranges, suppliers, recipes and other information.)

Humbrol: At the time I started, the most commonly used paint for model-makers in the UK was the Humbrol Paints range (called Plastic Enamel paint, not at all the same as real enamel!) and it was also used by ceramic restorers. Humbrol is still widely available, with little or no change. So that is what I started with, and used until I retired. Like many paints, it is applied from a White Spirit base, but can also be applied from Xylene .



GlasArt: The Humbrol Enamel paints are mostly opaque (like a good paint ought to be) but quite a lot of ceramics are decorated with transparent or semi-transparent colours – notably the cobalt blue widely used on Chinese porcelain, and the glassy decoration on Moorcroft ware. For this purpose I use GlasArt Paints, which are of course used for decorating glass. They are miscible with Humbrol, and can help to impart deeper shades to Humbrol where needed, without making them dull. They also may be thinned with and applied from white spirit or xylene.



Chinaglaze: When I started to look for a good non-yellowing medium for a glaze and a ground shade paint, Sylmasta was selling just such a product called Chinaglaze, and they still do. Some experimentation with this convinced me that it had all the properties needed to make a very satisfactory ground shade paint.

Sylmasta also sell “Chinaglaze Thinners” but I found that a good grade of Xylene works just as well at a much lower cost. If you prefer to use the 'Thinners' you will still need a lot of Xylene for cleaning purposes. Chinaglaze is not miscible with white spirit, nor with Humbrol or GlasArt paints.

Chinaglaze itself is clear colourless non-yellowing medium and by itself makes an excellent glaze. For a air-brushing recipe see Clear Glaze using Chinaglaze

For ground shades we need to start with a pure white; Sylmasta also sell a white Chinaglaze paint with titanium white pigment. I made my own white: “B” white mixture, but you may find it more convenient to buy it ready-mixed.

Chinaglaze needs to be cured at 80C to make it insoluble; it will not set hard at room temperature. This is very helpful for a ground colour, as you will see.



Toners for Chinaglaze (or “B”) white: The main use of Chinaglaze white is for Ground shade painting, and as I mentioned above, it is as close as you get to a pure white. You don't get as pure a white as this very often in your workpieces.

The natural colours of ceramics are mixtures of white (kaolin) with iron oxides and carbon black as contaminants. The iron oxide comes in the potter's clay, and the carbon black comes from the firing furnace. The pigments called ochres are iron oxides. The result is that the natural ground shade of ceramics can be matched, a surprising amount of the time, with only tiny amounts Yellow Ochre and Carbon (or Lamp) Black, in a pure white base. Referring to the colour circle above, yellow ochre is a rather dull reddish yellow. A tiny amount in the white will give a pale creamy shade, and a very tiny amount of black will make that cream duller and a little greener. The actual ground hue of your workpiece may be a little redder than this, depending on the clay, so you often need a reddish ochre to get just the right tone; I use Indian Red (another iron oxide) to adjust this. On the other hand, some manufacturers add a blue pigment to the white clay or to the glaze, to make it look less yellow (“pearlware”) so you may have to do the same. For this purpose, Cerulean Blue is suitable (or Cerulean Blue Hue). Other more popular blues (Cobalt, Prussian, Ultramarine) are transparent colours rather than opaque, and mixing them with opaque colours causes a problem with colour matching; the shade can change quite a lot as the paint dries.

So we need small amounts of up to four colours (besides white) to match practically all “white” grounds. You can use powder pigments for this purpose, but since the amounts needed are very tiny, it is much easier to use Winsor and Newton Artist's Oil colours, or the cheaper (and widely available) Winsor and Newton Winton Oil colours. These have a linseed oil base and in these very small amounts, no more than one part in 100, they mix easily with Chinaglaze without impairing its performance. They are available in most shops that stock artists' stuff, are quite inexpensive, and a 37ml tube of even the most heavily used colour, yellow ochre, will last for months or years.

If you need to match a strongly coloured ground, either mix Chinaglaze (white or glaze) with powder pigments, or use Humbrol/GlasArt colours, depending on the needs for further decoration on the ground.

Matt Colours: Whatever sort of paint you use, don't waste money buying matt paints. Use your gloss paints, and add Fumed Silica (Matting Grade) “Gasil” to the paint mix.

Acrylic paints – I know nothing! Having got this far with solvent-based paints at an early stage, I noted that acrylic paints, and notably the “Golden” range, were becoming popular, thought not at that time widely available in the UK. Since then, they have become ubiquitous, but since I had committed a good deal of time to mastering the techniques of the solvent-based paints, I never have got round to exploring the water-miscible paints in enough depth.

I am therefore in no position to compare or advise upon the relative merits, other than to say that solvent-based paints have the merit of rapid drying and an innate high gloss, and that water-based paints have the merit of not using (much) solvents. If you are starting out in this field, do take note of the acrylics, especially of Porcelain Restoration Glaze for example, from Addington Supplies. ( Addington's will sell you small amounts for evaluation.) Or check with your local artists' supplies.

I cannot leave the subject without remarking that the instructions for the airbrush application Porcelain Restoration Glaze do suggest to me that Chinaglaze is a lot simpler and quicker to apply.

Powder pigments: These are the basic colouring materials in paints, and it's useful to have some to add colour where it's needed. I suggest you don't buy any, until you find a definite need for them! Their positive value is that they nearly all mix well with nearly anything. They are largely inert and harmless, though chromium colours (e.g. chrome yellow) are slightly toxic, inasmuch as if you ate a couple of heaped teaspoonfuls, it could be fatal. The cadmium colours are also slightly toxic, but less so. Use disposable gloves and small spatulas when handling them, if only to keep your hands clean. A little goes a long way, especially if it's the wrong way. Particular applications are:

These pigments are quite expensive, and I found I used them very little, (other than titanium white for “B” mix, and Mars Violet for masking!) I have mostly used the Maimeri range; these are available from Stuart R Stevenson .



Gold and Silver Decoration. Quite a lot of the better porcelain and fine china is gilded. This is a layer of pure gold, When you have mastered everything else on this website, and are looking for a more difficult challenge, and have a good deal of spare money, you should consider learning how to do this with real gold, preferably by going to a course on the subject.

In the meantime, use the Metallic Paints available, which are rather good now, and reject any work with large broken areas of bright gilding. Do not be led astray by “easy gilding kits” available for a few pounds in craft shops.

I have not mastered the art of gilding, my remaining life being much too short for such a questionable investment of time and money.




The Ground Shade

About 10% of my workpieces had a ground colour only, with no decoration. This was mostly a white or cream coloured glazed finish, often simply the natural colour of the ceramic, but other colours might be used, sometimes with different colours inside and outside for vessels. In a few cases they were left in the bisque,with a matt appearance.




About 80% had a definite ground shade, plus coloured decoration, which might be in or under the glaze, or on top of the glaze.




About 10% were decorated all over, or very nearly.




Ground shade paint requirements:

It's clear that painting the ground shade, to cover restoration work and to provide a good basis for further decoration, is the most common requirement; and as it is applied first, I shall deal with it first.

It needs to be:

Chinaglaze White is very suitable: See Paint Ranges for Ceramics, Toners for Chinaglaze , “B” white mixture, and Clear Glaze using Chinaglaze.

Applying the ground shade:

It is nearly always best to apply the ground colour by air-brushing (Exception: see Tin Glaze Ware ). If you apply a some paint with a brush to part of a glazed surface, however well matched the colour is, you will always see a line where the paint ends. This is because the glaze lies like a pane of glass over the white ceramic ground, and the edge of the paint casts a shadow through the glaze.


But if you use an airbrush, instead of a sharp line, you will get a misty region of over-spray which is just as objectionable on a glazed surface (but not on a matt surface if you are using a matt paint). The reason for this is that over-spray leaves you with microscopic droplets of paint on top of the existing glaze, each of which casts its own shadow. This problem is dealt with either by masking or applying a clear glaze.

Masking. On decorated items, you need to protect existing decoration from over-spray either by cleaning it afterwards, or by masking it. Cleaning off is OK if the decoration is some distance from the bit of ground shade you are painting, but more often the two are right beside each other; then you need to mask the decoration to keep it clear of the ground paint. So before you start even mixing your ground paint, do the Masking (q.v.) first.

Preparing the Ground Shade paint. (These are my techniques as for a glazed ground, please yourself.) Set out all the necessary kit in your work cabinet: A selection of 1ml pipettes in a jar, a box of cotton buds, some cocktail sticks, a jar of Clear Glaze using Chinaglaze, a jar for waste liquid or paint, a small (~50ml) beaker containing a little xylene for cleaning purposes, a jar of xylene, a jar of “B” white mixture, a mixing stick with a flat end for the “B” white (a chopstick?), the airbrush set up in its cleaning pot and stand and connected to the compressor (see under Airbrush and Compressor), a black 6” (15cm) tile, a Mixing dish for ground colours, with its mixing brush (ibid.), and your Toners for Chinaglaze , a roll of cheap kitchen paper towels and a hair dryer somewhere handy. Put on your eye protection and your disposable gloves. Check that the compressor regulator is set to the right pressure.

If you are using Winton colours, apply a very small amount (~10mg) of yellow ochre and lamp black to the top of one of the dividers on the mixing dish. If you prefer powder, use a spatula or a cocktail stick to leave a little in the furthest quadrant.

Stir up your white mixture. In the recipe for “B” white, I recommended leaving steel ball bearings in the bottom of the jar. The white pigment settles to the bottom. With the balls in it, the paint can more readily be stirred up with a flat-ended stick to re-disperse the white. (You can try screwing the lid on as tight as you can and shaking it up if you like, but be prepared to clean up the mess.) Use a clean pipette, or one you keep for the white only, to transfert ¼ to ½ ml of white into the nearest quadrant of the paint dish.

Now take you workpiece, select a reasonably open area of the ground colour, and use the mixing brush to apply a small patch of white to it. Dry this off with the hair dryer, and inspect it, preferably in daylight, to see if it matches the ground shade exactly - hold it at arm's length without a highlight reflection on it. If you can't see the paint patch, you have a match (this actually happens first time about once in a thousand times) but usually it looks too clean and white. Then use your brush to touch the blob of yellow ochre, take off a tiny quantity, and put it on the edge of your little pool of white, then mix it in gradually to the white till it and the brush are perfectly even in colour. Then paint another small area on the workpiece, beside the first, dry it off and repeat your assessment of the matching. With any luck, you should be a little closer to the shade of the ground. If your paint is now much yellower than the ground shade, you have used too much toner! - throw out some of you paint into the waste jar if you need to make room, and add more white instead. When it is not yet as creamy as the ground, repeat the addition of tiny amounts of yellow. When it is about as creamy, it may still look too bright, against a duller shade; if so, add an even tinier amount of black. By maintaining a chain of colour patches starting from pure white, you can see how you are approaching the matching shade. Quite often, the yellow/black mixture hits the match, but sometimes the best you can get with it looks a bit dull and green/khaki toned – in this case you need to add a third colour, a tiny amount of Indian red. Conversely, if your best yellow/black mixture is already on the beige side of the ground, add a little Cerulean Blue.

This process is very frustrating at first, but you will learn with experience. Be patient and persevere!

When you reckon that you have got a good colour match, you need to check it using the airbrush. If you have not used your airbrush today, make sure it is quite clean and working OK by putting a little xylene in the paint cup. Put your finger over the nozzle and press the air control gently to bubble a little air back through the solvent. Then spray it out on to a white tile to make sure it is perfectly clean and working right.

Thin your paint mix with several drops of xylene to about the consistency of full-cream milk. If you splash the brush in and out of the paint a little, and you get a few drops of paint running around the surface before they are re-absorbed, you are not far wrong. Use another pipette to transfer about ¼ ml into the airbrush, and turn on the compressor. Carefully spray a little on to the black tile, till you have about a 1cm solid spot. This should be nice and smooth, inside a ring of over-spray. If it has a surface which looks like orange peel, your paint is too thick. Empty the airbrush into the mixing dish and thin the paint with a few drops more xylene. Otherwise, test spray a small area of your workpiece, moving the airbrush about an inch or two from the workpiece in a small circular motion:




and when you have smooth application, put the airbrush back on its stand and dry the test patch. Check again for colour matching. I have often found that this test shows up a slightly deeper shade than brush test matching. If this happens, empty the airbrush back to the mixing dish and add a little more white, perhaps 5% to 10%, and re-mix. Rinse the airbrush out with a little xylene, and try again. When you finally get an exact match, and the paint goes on nice and evenly, you are ready to paint: but first clean off all the test patches on your workpiece and wipe it dry with kitchen paper.

If you have managed to get your paint matched and ready in less than 15 minutes, consider yourself an expert.

Matt Colours: Some workpieces remain unglazed (bisque), such as many French figurines and Parian ware. Add Fumed Silica (Matting Grade) to the white paint, about one part by volume of 'Gasil 23' to two of white paint for starters. Proceed with your colour matching as before, but check that the matt effect is also satisfactory – some items are semi-matt and can be tricky. For completely bisque items, you should need no glazing. For semi-matt finishes, you may need to make up and apply a semi-matt glaze, (mix some fumed silica into a little glaze) if over-spray looks to be problem.

Painting the Ground Shade is now the easy bit. Switch on your work cabinet air extraction if you haven't done so already. If your workpiece is hollow and both inside and outside are to be painted, do the inside first. If you are to paint the inside of a vase or jar, make quite sure that there is no dust or loose dirt left on the inside, or the airbrush will blow it back out and leave it all sticking on the inside top! If you are painting right round either inside or outside a circular workpiece, it's sometimes helpful to put it on the Turntable and rotate it gently while holding the airbrush in about the same position. When painting the inside of deep vases (should it be necessary) there is often no way you can get the airbrush near the bottom, you just have to spray a good deal as far as possible into the middle of it and hope for the best. A lot of paint spray will of course come right back out but much of it will stick on the inside walls.

Use specular reflection. You will be mostly applying paint on to a surface of identical colour, and it's not easy to see what you are doing! But most of the time, both the paint and the workpiece are glossy, so you hold the workpiece so that you can see the reflection of a bright light (usually in your work cabinet) on the surface where you are painting. This is where a strip light (of any old colour) is really useful. This sort of reflection is called 'specular' (from the Latin for 'mirror') and it allows you easily to see the paint, the ground and the over-spray between them.

Spray in stages. On restored parts of the outside, apply the paint gradually: using the circular motion shown above, first cover the area to be painted with a light coat, little more than an over-spray, to ensure that following coats have a good base to stick to, without causing runs. Continue applying increasingly heavy coats until the restored area is smooth and glossy and no repair work (white Milliput) shows through.

Flaws and faults: If you find a tiny hole, which you had not seen before, in the workpiece when painting over a join (see A further hazard ) stop, remove all the paint and go back to fill the hole properly, no exceptions. If you get an tiny edge or flaw other than a hole, you can sometimes fill it to look smooth enough by adding more coats of paint in that area. If you get a little bit of loose dirt trapped in the wet paint (squiggly little bits of fibre – as from cotton buds - are not uncommon) you can often remove them with a sharpened cocktail stick, and smooth the area by spraying on a little paint thinned with more solvent.

Remove the masking: As soon as you have put your airbrush back in its holder, remove the masking. If it is tape or cling film, just pull it off carefully from a free (unpainted) end. If it is done with Masking liquid, touch a free end with the masking brush (which I told you not to clean, and therefore has a blob of hardened masking liquid still on it), which will stick to it, then pull it off carefully – it will stretch a lot; if you pull too hard it may snap back on to your wet paint. Remove any left-over bits with a cocktail stick. Check carefully to be sure it's all off. If there are any obvious flaws you can correct quickly (ragged edges, finger marks, paint splashes), do so before glazing.

Glazing, and getting rid of over-spray. So as quickly as you can, when you have applied your paint, dump the contents of your airbrush paint cup back into the paint mixing dish. Flush out your airbrush with a couple of changes of clean xylene and clean the inside of the cup with a cotton bud. Fill the cup with the clear glaze solution, spray a little on to your black tile to be sure that it's clean and thinned correctly, then airbrush over the original paint, and the accompanying paint over-spray. This dissolves the little over-spray droplets,and produces a smooth gradient of paint. The glaze itself will however leave a faint but objectionable over-spray, of microscopic droplets of glaze, each of which forms a tiny lens! Flush your airbrush out once more, and fill it with pure solvent, and spray over the over-spray from the glaze to level it out. Inspect the result under a good light, make any final corrections, and leave it in a warm and non-dusty place to dry. Do not get rid of the paint in your mixing dish until you are sure the job is done.

Avoiding paint runs: This works best with a volatile solvent like xylene, which dries while you apply it, and rarely runs (once you have got used to your airbrush!). If you are using white spirit, or are using a water-based paint, drying is much slower, and the chances of getting paint runs are much increased. You may need to apply the paint in two or more coats, allowing partial drying between each.

Mass production: It often happens that you have several workpieces which need plain grounds painted at about the same time. Some may have the same ground shade, as in members of the same set; others may differ in shade, but not by much. In such a case, apply any masking to each, and arrange them in order from the whitest to the dullest ground shade. Start of with the whitest; when it's done and glazed, do not clean out your paint dish, but adjust the shade and quantity of the paint in the dish to match the next item in the sequence, and paint that, till you have done them all. This saves a lot of time and cleaning material.


Airbrush Maintenance [The next two paragraphs refer specifically to the airbrush type mentioned in Airbrush and Compressor]

Clean your airbrush thoroughly after each session. Think how much it cost you, and how inconvenient it would be if you had to send it back to the maker to get cleaned out!. You will note that, if you are glazing your workpiece, you will have given the airbrush quite a good clean out with the final solvent spray. This is a good start. Now remove the needle, the needle cap (foremost) and the nozzle cap (next foremost) and clean each of these with the paint solvent you have been using, especially inside the caps. Use a pipette pushed into the paint cup towards the front to flush out the mixing chamber and the nozzle itself as far as possible. Clean the paint cup with a cotton bud, being particular around the bottom of the cup. Any residues may contaminate subsequent paintings. Finally put a little xylene in the paint cup. Put your finger over the nozzle and press the air control gently to bubble a little air back through the solvent. Then spray it out on to a tile, white for coloured paint or black for white paint, to check that the solvent is now clean. Replace the front caps, but leave the needle out if you are finished with it for the day, to allow the interior to dry out overnight. Dry out the moisture filter, or empty it, after each session.

Sticking needle: You should not normally remove the nozzle (there is a little spanner in the kit provided for this purpose) unless you have noticed that the needle is getting stuck and not seating down properly. This problem occurred on my (very old) model using xylene as a solventbut not with white spirit. More recent designs may have solved the problem better. Where the paint mixes with the air, just behind the nozzle, and in the back of the nozzle itself , there is a space where paint can dry out a little as the needle goes back and forth, and can gradually builds to impede its forward movement. If this happens, you lose some control of the airbrush, and have to regulate it by the airflow rather than the needle. If this happens, clean it out in the usual way, leave it overnight to dry, then put on you magnifying glasses and:

Clean up the rest of your kit too, (use kitchen paper for wiping) and put everything in its proper place.

Drying and Curing the Ground Shade. In most cases, you want to cure the ground shade before you start the decoration painting, so that you have a hardened ground shade which you can decorate, and be able to adjust and correct any mistakes, without damaging the ground.

An exception to this would be further decoration based on xylene solvent, as in Example 7 Porcelain Gilded Vase – because using xylene on a cured Chinaglaze surface will soften and swell the paint, causing it to wrinkle. An uncured surface will absorb the solvent much more easily.

Allow the paint to dry overnight, and then cure it in an oven – see Oven types and curing times – raising the temperature gradually as described. When it is cool, it is ready to decorate.



Decoration I define as the process of applying everything after the ground shade

I have always used Humbrol Paints ,GlasArt Paints, and Metallic Paints this purpose, with Disposable palettes mostly. I have used three methods of application, by Paint Brushes , by Airbrush and Compressor which is often done with Masking, and by Finger Painting. Please refer to these links for most of the information on their use, and see Applying the ground shade for the operation of the airbrush.

Paint Brush Decoration is used for most of your detail and pattern work, as in Example 2 Chinese porcelain plate.

Mixing: Use Disposable palettes and your oldest (otherwise useless) brushes for mixing your paints, which are selected from the Humbrol and Glasart ranges. It's a good idea to keep you miniature paint pots on a small tray, which can be taken out of your work cabinet, ideally with a low rim to contain possible spillages.

For each colour you want to mix, open the tins of Humbrol and mix each with a cocktail stick with the point cut off, then transfer a few drops to a well on the palette. GlasArt colours don't settle out in the same way, but they can deteriorate; use cocktail sticks to transfer these too, but if the paint has set to a jelly it is no longer fit for use.

Mix your colours in the flat space in the middle of the palette, and check your shade matching on the workpiece. These take longer to dry than the Chinaglaze ground colours; you need about 30 seconds with a hair dryer.

Matching a colour: This is an acquired skill, you learn by doing it. Use the colour chart under Properties of paint as a guide, and make up a set of colour tiles as I illustrated in that section, to act as a guide to your eye.

If you cannot reach a deep enough shade with Humbrol paints, add a corresponding GlasArt colour to the mix.

If your colours are too bright, you can usually dull them best with Humbrol Brown 10 rather than black.

If your colours need to be matt, rather than glossy, add Fumed Silica (Matting Grade) (Gasil 32) till it looks right.

A couple of frequently used colour mixes (Chinese Blue and Chinese Terra Cotta) are described under Example 2 Chinese porcelain plate

When you have finished the job, clean only the flat mixing area of the palette; leave the paint in the wells where it can dry, and use each with the same paint as long as it's usable.

Brush Application problems: We have all used paintbrushes at one time or another and much of this is common sense. A few unexpected problems are:

Circular Lines: see Example 2 Chinese porcelain plate again!

Tin Glaze Ware: Dealers and collectors of antique tin-glazed pottery prefer to be able to discern exactly how much restoration has been done – inasmuch as very little has survived in perfect condition.(jm1418).


Be sure to ask your customer how he wants it restored! Plates in particular often have chipped edges because the earthenware ceramic is poor and the glaze is thin on the curve of the edge. You will probably not be required to restore the rim where only the glaze has been lost. You will probably be required to fill crescent-shaped chips (use Milliput shaded to match the earthenware colour), and paint it up with a brush, because air-brushing does not make clear the extent of the repair. When you are applying the ground paint, therefore, use a brush and keep the extent of the painting as little as you can beyond the extent of the repair. Use a small flat brush (say 1/8 inch) to feather the edge of the painted area.

Airbrush decoration is best used for:

The airbrush is also used for Shaded Effects, not only on skin shades, but especially on Beswick and other animal items, and drapery on figurines. In this application there is an “under colour” which may be the ground shade or an area of smooth colour applied as above, and a shading colour which is often transparent.

A simple example of this is Example 5 Beswick horse and rider, where the white horse (the ground shade) has dark grey markings airbrushed on with Humbrol.

A more subtle example is shown below: (jm1204).

After repair, I used a Humbrol medium brown under colour, airbrushed on, to cover the breaks. I cured this and followed it with a transparent greyish brown GlasArt coat, to give the shaded effect. This is one of the most difficult jobs, both in the shade matchings and in the control of the airbrush – fortunately, it is generally not necessary to reproduce the exact shading, only the general effect.

For drapery, as in Example 1 Royal Doulton Figurine , if the skirt were damaged or chipped (which it isn't in this example) I would use the airbrush with a Humbrol pink to get the under colour of the skirt, then GlasArt applied with a round brush to do the shading – which was clearly done with a brush on the original! To adjust the depth of the transparent colour, use GlasArt Clear 400 in all cases.

For these shaded effects, dry the under colour thoroughly overnight before applying the shading, and preferably harden it with a light curing, at 60-70C for half-an-hour, to enable it to tolerate some correction when applying the shading. If you need to make a correction, try dry wiping with kitchen paper; if you wipe with white spirit you risk taking off the under colour.

After you have applied the shading, follow this directly with Humbrol Glaze 35 applied by airbrush to smooth the over-spray effect and ensure an even glazed surface.



The airbrush may be needed for plate rim lines, with suitable masking – see Circle Cutter “Xcut”, where the lines are too long and fine to be done with a brush on the turntable.



Finger Painting.

Moorcroft ware decoration poses a unique appearance problem. A chipped rim may sometimes be redecorated by simply by airbrushing and glazing, but neither airbrushing nor brush application gets the finished appearance of the coloured areas shown on the example below After much experimenting, I found that finger painting did the job, using Humbrol colours with GlasArt for the deeper glassy shades. (Disposable gloves are recommended!) Outlines may be completed with a round brush. Moorcroft often use the deep Chinese Blue colour, noted elsewhere.





Final Inspection

When all the work is done and the workpiece is dried and cured and cooled, inspect it carefully with magnifying spectacles in your work cabinet by specular reflection under the strongest light for any flaws in you work. It is very easy to miss faults in something with which you have become too familiar. Look for smudges, fingerprints, missed bits in the decoration, stray bits of over-spray, cracks and bad edges in more complicated assemblies. If in doubt, check the photos you took before restoration, to check for original manufacturers' mistakes, for which you are not responsible unless so requested.



Ask yourself: Is it right or is it wrong? If it's not right, and it can be put right, do that.




Examples Of Restoration

Example 1 Royal Doulton Figurine

Example 2 Chinese porcelain plate

Example 3 Heubeck bisque figurine

Example 4 Satsuma biscuit jar

Example 5 Beswick horse and rider

Example 6 Two Beleek First Period Jardinières

Example 7 Porcelain Gilded Vase

Also, click hyperlinks for sources of tools and materials!



Example 1. Royal Doulton Figurine in bone china. (jm276)


The neck had been broken and repaired. I opened the join by pouring boiling water on it, and after dishwashing, found it was a clean break with only a little splintering. The join needed no special support, so when it was dry, I applied Araldite 2020 Thin mix (3 drops to 1) as it stood, and wiped off the surface with a cotton bud.

The following morning the join had set well, so I cleaned it with methylated spirit, and dressed it with Milliput Dressing mix and left it overnight again.

I then cured both the adhesive and the dressing in the oven at 70C, and smoothed the dressing with 150 grade Glass Paper and 2400 grade MicroMesh AO polishing cloths. It was then ready for painting.

I masked the adjacent areas (collar and hair) with Masking liquid, and used the airbrush (as for a gound shade) to apply the skin colour, then removed the masking, glazed the area, and used a fine brush with xylene to soften the lines where collar and the hair adjoined the skin shade.

The job was completed by leaving overnight and curing.



Example 2. Chinese porcelain plate (jm977)


This was a nice clean break, with no springing, although the front glazing was splintered. I put on a pair of disposable nitrile gloves, and with the plate face down (so that the join was clearly visible, and not confused by the pattern), I held the join together as closely as possible, and applied three small drops of cyanoacrylate superglue using a microbrush , one towards each end and one in the middle. I held the plate for a count of twenty, sufficient to let the plate set.

I then turned the plate over on its face and made up 6 drops of Araldite 2020 A plus 2 drops of 2020 B, and used an Ultrabrush to apply a narrow line of 2020 along the join, and left it to sit overnight.

The next morning, I scraped off remaining 2020 from both sides with a curved modelling knife, and cleaned remaining streaks with methylated spirit. I dressed it with Milliput Dressing and left it overnight again.

I then cured both the adhesive and the dressing in the oven at 70C, and smoothed the dressing with 150 grade glass paper and 2400 grade polisher. It was then ready for painting.

I made up the ground colour, applied it to the back and glazed it. When this was sufficiently dry I turned the plate over and masked patterned areas adjacent to the repair along existing pattern boundaries, with Masking liquid. I then airbrushed the join on the front, removed the masking and a little over-spray past the masking, and glazed this too. I let this dry overnight and cured it ready for painting.

Approximate recipes for brush painting:

BLUE: 1 drop GlasArt Turquoise, 3 or 4 drops of GlasArt Violet, Humbrol White 22 to match various depths of blue. This turquoise/violet mix gets round the Metameric problem.

TERRACOTTA: 4 drops Humbrol Brown 9, 1 drop Humbrol Dark Brown 10, 1 drop Humbrol Red 19, Humbrol White 22 to match various depths Humbrol White 22 to match various depths.

GROUND SHADE for correction in patterned areas (see Brush Application problems ): Humbrol White 22 shaded with tiny quantites of Dark Brown 10 and Blue 14.



Example 3. Heubeck bisque figurine – head (about 5cm diameter) smashed (jm10)


Using a microbrush, I joined this up bit by bit with the thinnest available cyanoacrylate superglue , into two main parts. I planned it so that the final join was to be made between the front and the back of the head, rather than down the face which had to be near perfect. I filled some small gaps with Milliput, but did not smooth them down at this stage.

I then coated the whole inside of each part with a thick mix of Araldite 2020 and Cab-O-Sil, and joined the two parts with the same mix. I removed the external surplus with a cotton bud, and left the assembly overnight to set with the join more or less horizontal. The tough internal 2020 layer strengthens and holds the brittle superglue assembly together. After curing, it was ready to be joined to the body, which was more or less intact.


After assembly, and filling and smoothing the joins, I redecorated the head by brush with matt Humbrol colours.



Example 4. Satsuma biscuit jar, 14cm diam. (jm1712)

Bisque creamware inside with heavy glazed decoration on outside. Broken in 9 pieces, all present and clean. Also lid (intact) and wicker handle. (For display only. )


I made a temporary assembly of the whole jar using masking tape, applied on the INSIDE. (a curved join can't swing open if taped on the inside). While applying any necessary additional pressure to keep each join well closed, I applied thin superglue to each join, since the glazing was thick enough (about 1.5mm) to hold the assembly together. I then removed the masking tape from the inside, and applied a thin solution of Paraloid (in acetone) to the joins on the creamware interior. This soaks in but consolidates the material; a second coat of the thin stays on top of that and makes the join more solid. Paraloid leave no watermark on the creamware. My client wasn't interested in improving the interior any further since it was for display only.

It would be wrong to assume that this was a really sturdy assembly, but it was strong enough to survive some filling of small chips, and enough redecoration to make it acceptable for display cabinet..

Necessary decoration on the outside was done using mostly GlasArt colours.

Example 5. Beswick horse and rider (jm1452)




(actually the Duke of Edinburgh, on 'Alamein' at Trooping the Colour 1957 ) I kept this box specially for Beswick horses, which often get their legs broken. Underneath the tissues is a length of plastic foam insulating material ¾ inch thick for a 3 inch pipe, slit along the side and fitted into a convenient size of cardboard box. (Try https://www.pipelagging.com/ for “Pipe Insulation 80mm Bore 19mm Wall x 2m Class O Armaflex Tube.” You can buy a 2 metre length on the web. )

This, suitably augmented with other packing material, makes an ideal way of holding Beswick horses, in a sort of gentle vice, in a position where their legs ( three broken in this case ) can be reliably reattached with 2020 Thick mix.

Once the workpiece had been secured in this way, it was possible to join broken legs as described. The following morning the join had set well, so I cleaned it with methylated spirit, and dressed it and some minor chips on the hooves with Milliput dressing mix and left it overnight again, and checked that it stood level!

I then cured both the adhesive and the dressing in the oven at 70C, and smoothed the dressing with 150 grade glass paper and 2400 grade polisher. It was then ready for painting.

The white ground shade and glaze was applied to the legs; with temporary masking of adjacent legs. After drying and curing, I applied the black (actually very dark grey) Humbrol shading to the legs using the airbrush, ( Airbrush decoration ) again with temporary masking. The hooves were finished with a small brush.



Example 6 Two Beleek First Period Jardinières, 28cm high, each originally decorated with three birds (jm1602/3)




jm1602 (on the left) had lost two of its birds. The remaining bird had lost part of its left (outboard) wing, and the whole bird had been broken off and glued back on. There was also a chip off one of the three pot feet.

jm1603 (right) had lost one bird, and one of the remaining birds had a broken wing, and the other,a broken tail.

Each remaining bird was different, and each was perched more or less precariously on two porcelain legs, plus some other attachments.

My customer, who was an antique dealer, required the birds and the chipped foot to be restored, and to ignore other (relatively minor!) damage.

The only sensible option was to remove the glued-on bird, and use it to mould three replacements; and then to restore the other damages in situ.

The following is a (tidied-up) transcript of my notes, on a day-to-day basis. This is not to say that any of these was a day's work; I was working on other items concurrently, as I note under STAGES in REPAIR and RESTORATION.



  1. Because Beleek used a mark which was sometimes not fast to washing during their Second Period, I protected the mark on both items with a coat of Humbrol Gloss (no. 35)

  2. I detached the glued-on bird from 1602 with boiling water (see Dismantling ) and dish-washed the jardinières and the detached bird. I allowed them to dry overnight.

    I used this detached bird as follows:

  3. I drilled holes for wire for the missing parts: 2 wings and 1 tail, and put in pieces of florists' wire with Araldite Standard (see Extra support )

  4. I used Godiva Modelling Wax to take impressions of a suitable tail and wing (upper surfaces) from the birds which had them, for replacements. I could use an impression rather than a full moulding because while feathers were modelled on the top, the undersides were plain and could easily be shaped to fit.

  5. I filled these impressions with Restoration Plaster and allow to set, then trimmed off surplus from undersides, and to fit breaks as closely as possible. I connected the replacements to the breaks as described in Larger missing pieces using Araldite 2020 Thick mix as adhesive and allowed it to set overnight,

  6. then cured the loose bird and the two jardinières in an oven at 80C for half-an-hour, to ensure that the joins had set hard. ( see Oven types and curing times ).

  7. I filled imperfections in the joins with Milliput Superfine White and Milliput Dressing and. allowed them to set overnight,

  8. then used Glass Paper and Small hand tools to shape feathers over the joins, and applied Milliput dressing again to cover imperfections, allowed to set overnight, cured and reshaped once more. (repeat till satisfied!) I now had: 1602 with no birds at all attached, and one detached bird restored, suitable for casting, and 1603 with two birds restored ready for painting, and one bird missing.

  9. Details of moulding and casting are described under Full Moulding and Casting as being of general interest!

  10. Painting and fitting the castings:

    Once I had three good birds cast (out of four attempts) it was a matter of fitting them, and the original bird, on to the jardinières. But once fitted, they would be difficult to paint, so I prepared each bird and its mounting so that they could be fitted on with a minimum of work, masked off the joining areas, and then air-brushed each bird with my “B” Chinaglaze white mixture, (shaded with Yellow Ochre and Lamp Black), and glazed but did not cure the paint, because it would need more air-brushing when the joins were made.

  11. I joined the birds on to the jardinières using Araldite Standard, and tidied the joins when the adhesive had set.

  12. I then airbrushed the joins to blend in, allowed the paint to dry, and gave them a final cure.



Example 7 Porcelain Gilded Vase on a cobalt blue ground (jm892) Probably 19th C. Coalport

Screwed joint between vase body and foot - just above the second background line up in the picture below. Body was broken at top rim (6 pieces) and at base of vase body (20 pieces), all badly glued and re-painted. All breaks are on blue or gilt – only small scratch on picture ground. The foot was rust stained but otherwise unharmed.


I dismantled this by removing a rusted-up screw by drilling, to remove foot; and then using boiling water to open the glued joins (see Dismantling ). I then used phosphoric acid to remove rust stains ( see Bleaching ) I cleaned off glue residues and gold paint by using Nitromors (see Dismantling with Paint Stripper ). I re-assembled vase body by tacking with superglue and strengthening with Araldite 2020, as used in Example 2 Chinese porcelain plate Filled the joins and dressed using Milliput (see Smoothing Joins And Filling Chips ) then painted as follows:

  1. Chinese Blue airbrushed on top rim and base of vase body. Allowed to dry, did not cure.

  2. “B” white mixture (suitably tinted) airbrushed for inside top (not shown). Allowed to dry, did not yet cure.

  3. Made circular masks of thick cling film (see Masking ) for top, and cut stencil (ibid.) for pattern at bottom.

  4. Airbrushed Sylmasta gold paint (see Metallic Paints) on masked areas

  5. Finished gilt detail using brush with Revell gold mixture (ibid.)

Cured as detailed in Oven types and curing times

Re-assembled with foot, using studding (screwed rod) and washer made from cork sheet (to cushion ceramic surfaces) from http://hobby.uk.com/



Before and after – top of vase.




EQUIPMENT MATERIALS and TOOLS



Araldite 2020 500 g White Dual Cartridge Epoxy Adhesive http://uk.rs-online.com/web/ and others


NOTE: There is an expiry date on the bottles. I have ignored this for years at a time, without adverse results. They don't seem to sell it in smaller quantities now.

See How to use Araldite 2020


Araldite Standard 32 g Tube Epoxy Adhesive http://uk.rs-online.com/web and others


See How to use Araldite Standard




Araldite Instant 24 ml Transparent Syringe Epoxy Adhesive http://uk.rs-online.com/web/ and others


See: How to use Araldite Instant




Very thin (penetrationg) cyanoacrylates:

REACT cyanoacrylate (THIN): https://www.wonderlandmodels.com/brands/react/

ZAP CA from Argos or E-bay: or search for “low viscosity cyanoacrylates” on the web


.

NOTE: Don't buy a large bottle! Buy two of the smallest size you can get. You need only tiny drops most of the time, and you will most likely find that the bottle in use either (a) starts to thicken too much when has been exposed to air many times or (b) glues its own top on so thoroughly that it is impossible to open ever again. When either of these happen, move calmly to your unopened reserve bottle, and replenish your stock.

If you unscrew the top entirely, keep the bottle in

Application: See Cyanoacrylate Application






Ultrabrush Regular http://hobby.uk.com/catalogsearch/result/?q=ultrabrush&x=0&y=0

Microbrush Superfine (white) http://hobby.uk.com/catalogsearch/result/?q=microbrush&x=0&y=0





Milliput Superfine White Widely available in craft shops, hardware stores, and the Web.




Keep the sticks wrapped up in their original wrappers when not in use! Substantial shelf life but the yellow stick tends to harden after a long long time. (It's worth checking this if you are buying it in a shop where the turnover may be very slow, because it can make mixing difficult. Especially the coloured versions: a rather coarser grade is available in black and terracotta; perhaps worth picking up some for particular jobs, if this sort of colour is involved.)

See Milliput Application


Glass Paper: An abrasive is needed to smooth down excess adhesive on joins, and fillers such as Milliput. For this purpose you need an abrasive that will not scratch the ceramic, either the glaze or the bisque. Until the nineties most 'sandpapers' for hand use were of this type; glass doesn't scratch glass. More recently, most of the 'sandpaper' or 'glasspaper' you can buy in a hardware store use aluminium oxide or other harder abrasives, which last a good deal longer and are suitable for most jobs, but will scratch ceramics.

The following is the ONLY British genuine glass paper now available, and most hardware stores do not stock it: you have to hunt around on Web It is described as GLASS PAPER CABINET 117.





It is available at http://www.coopersdirect.com/index.php?q=glasspaper&option=com_customfilters&view=products&Itemid=144

and

http://www.consumableitems.co.uk/CONS114200/norton-oakey-cabinet-glasspaper-280-x-230mm-3-30

in grades from 40 up to 240: I find 100,120, and 150 grades to be the most useful; 240 is good for finishing but I prefer usingMicroMesh AO polishing cloths

The coarser grades may be used for shaping joins, fillings and casts where Milliput, Restoration plaster or Polyfilla has been used, by wrapping round a hard wire or a dental tool (see Small hand tools ) or making a small roll or a folded edge of the glasspaper alone.


MicroMesh AO polishing cloths: (that's “A Oh” not “A Zero”)

http://www.stuartstevenson.co.uk

who keep an immense range useful stuff for artists and related occupations; you can't order directly on the Web (at the time of writing, May 2016 ) but you can download or view their catalogues as .pdf - find this under Gilding and General Materials catalogue, page 36. On page 38 you can also find the real glass paper as above. Buy only one or two 6 * 12 inch sheets of each; they are re-usable and last a long time.

Also directly at Sylmasta : Micro Mesh Aluminium Oxiide Finishing Cloths



There are a lot of other types of Micromesh cloths but many are of silicon carbide which will scratch ceramics.




Emery, or Silicon Carbide Paper (a.k.a. “wet and dry”) can be used when it is necessary to abrade bad joins down. You can get this at any decent hardware or tool shop. Use 240 for the main work and 320 to smooth out the tiny scratches.







Disposable palettes: For mixing paints for brush application, adhesives and dressings I have generally used old meat trays (from the local supermarket) well cleaned and cut in two:

The type illustrated has little wells round the side, about 1ml in capacity, and a flat place in the middle where you can blend the small quantities of paint usually needed. For paint, put a few drops of each colour in a well as needed. When finished painting one colour, just wipe the middle bit clean and proceed with the next colour:


When finished, wipe the middle clean and leave the paint to dry in the wells. Next day, just put more of the same paint in each well as required. Throw it away when the wells get clogged up.



For mixing Araldite 2020, the capacity of these wells is just right – big enough for most jobs and small enough for economy. It is also convenient for adding fumed silica and any pigments required, and mixing to the right thickness with a small palette knife or brush. Leave the mixture in the palette overnight, and you can check that it is set properly when you come back to it. Also, it doesn't stick to this sort of plastic, so you can then usually pop the set piece of 2020 out and re-use the well.

For mixing Milliput dressing (q.v.) pour roughly equal quantities into well and mix with a palette knife or similar, rather than a brush, which encourages bubble to form.

The point of all this is to save time and solvents on the job of cleaning tools and palettes; time and solvents cost money. You can't generally buy meat trays by themselves (unless you want to place an order for 10,000 minimum) so you have to buy the meat as well. ( vegetarians will have to ask their carnivorous friends ) When you are buying your meat in trays, have a look at the bottom to make sure that the wells are a useful shape – I find the type illustrated is often used with Sainsbury's minced beef! So enjoy your bolognese.

The nearest thing have been able to find among art supplies is the Pepeo Disposable Pallette, at about 45p each, available from https://www.jacksonsart.com/ and probably others; this has 16 wells; for paint you need a mixing surface or vessel as well.



Mixing dish for ground colours: I prefer to use a simple porcelain paint saucer divided into quarters for this purpose. They are easy to clean (unlike plastic dishes), and each compartment holds up to 2ml of paint, which is enough for most jobs. (If you need more for a large item, or if you need to keep some for other items as in a set, it may be better to use a 15ml jar for mixing. The item shown below is available from Ken Bromley Art Supplies




Use a long flat brush about ¼ inch (6cm) wide with synthetic bristles (not hog) for mixing. Use one quadrant, or a divider, for your toner colours, and mix your ground shade paint in the opposite quadrant.


Fumed Silica (Filling Grade): Cab-O-Sil from http://www.ecfibreglasssupplies.co.uk/p-838-cab-o-sil-fumed-silica.aspx or others. It is a very light powder, weighing only 50g in a litre volume; so 250g will last you a reasonable time. Used for thickening liquids, in this context, peroxide and phosphoric bleaches, and Araldite 2020 adhesive. Irritating but not harmful if you breathe it in; wear a dust mask when you're opening the bag, if you have one handy


Small hand tools




Modelling knives: to be found in hobby and craft shops: I find 0022 (wider, curved) and 0011 (narrower, straight) to be most useful.

Modelling tools: 3 dentists' tools, selected for my preference: but see the comprehensive set from Toolzone below.

Two lengths of stiff iron wire, one cut from fencing wire, and one from a clothes hanger: I use these to wrap Glass Paper round to access awkward places when rubbing down.

Tweezers: most useful ones are long ones with curved points, and medium length with accurately ground points and a slide to maintain grip.


Toolzone 12-piece wax carver set, available from Wonderland Models (Toolzone don't sell to the 'general public' but their website is a mine of useful items – see https://toolzonetools.co.uk/)




Magnifiers

Some sort of magnifying glass, and a pair of off-the-shelf 3.5 dioptre reading glasses with 3 or 4 dioptre flip-up clip-ons (E-bay etc.) - for really close work, especially if you need reading glasses anyway. These specs get hard usage with paint spray etc. and should be regarded as semi-disposable









Scales

On Balance Proscale Digital Pocket Scale 100g x 0.01g PRO-100A (E-Bay, Amazon etc; copy this full description into your search engine)


This is an excellent little scale, but must be protected from ACETONE which dissolves it. A piece of polythene will suffice. See application in Milliput Dressing




Beakers: cheap disposables in supermarkets; durable glass and plastic goods in E-Bay under “Laboratory Beakers” . (Araldite 2020 comes with a couple of handy size: you don't need them for the adhesive,)


How to pour liquids accurately from a beaker:

For example: plaster from a cheap disposable plastic beaker, solvents and other chemicals from any sort of a beaker, which you don't want to have dribbling. This is an old chemists' trick. (I'm an old chemist)





Pipettes: 1ml semi-disposable. I find this size most convenient all round for transferring small quantities of liquids. For measuring Araldite 2020, transferring paint into airbrush cup, etc. Also in demand for 'vaping'. E-bay “plastic laboratory pipettes”, Argos.





Mini-drill and diamond rotary burr dill set

Not much used, but surprisingly cheap and sometimes indispensable.

Lots of these available on E-bay. Don't waste money on grinding, sanding, cutting, or polishing attachments. Used for: drilling holes to take wire for modelling or re-attaching thin things like figurines' arms, jug handles etc.; and also for grinding out deeply fouled chipped areas before filling. Twist drills may be useful for non-ceramic materials.





The Airbrush and Compressor.

Together, these are the single most expensive piece of kit that you must have. Expect to spend some £00's

I have no hesitation in recommending:

The Airbrush Company Limited which is the only supplier I have used. They have a huge range, a comprehensive website, and excellent technical service. You may find other suppliers a little cheaper, but not any more helpful.

The airbrush I have used for twelve years , which I have found very satisfactory, is an earlier version of this one. The only change I would recommend is to specify a 0.3mm jet, instead of 0.2mm.



Iwata HP-B Plus Airbrush (specify 0.3mm jet)








A compressor to go with it is:

Iwata Studio Series Silver Jet Compressor


This comes with two important features: an air pressure gauge and control, and a moisture filter which is attached underneath the the airbrush. (The moisture filter is an essential; having purchased a different brand of compressor, I found myself having to devise an in-line moisture filter out of odd bits of plumbing, in order to avoid my air-brushing being punctuated with splashes of water which had come up the line. Should you find yourself in this position, the moisture filter can be purchased separately.) My model is different, but I set mine to give a static pressure of around 3kg/sq.cm or 40 psi; this reduces to a working pressure of about half of that.



I recommend these cleaning accessories:








Turntable

You will have noted that many ceramic objects are round. In redecorating round objects, a turntable is practically essential. A potter's wheel springs to mind, but these are heavy and fairly expensive, and usually too high for convenience in decoration, especially of plates. The other round things which are much decorated, are cakes: so search E-Bay under “rotating cake icing” for something like the 10 inch example illustrated, at the right height and price.

NOTE: you may find it convenient to cut a 12 inch circle of cardboard (using the circle cutter described below) and stick it on the turntable (using a temporary adhesive like “Pritt”) then use a liner brush to draw concentric circles on the cardboard, while spinning the turntable. This simplifies the positioning of workpieces and protects the turntable itself. Replace when soiled.



Circle Cutter “Xcut” 32cm / 12 ½ inch diameter cutter for light card etc. Useful for cutting masks for restoring circles on plates etc. - a common requirement. Available in most craft shops, Amazon and E-Bay.



Application

Use it with Static Cling Window Filmwhich is a thick cling film, with a paper backing. Use the frosted clear type. You also need a simple tool to measure the angle of dishing on a plate:




Make the tool up as follows: use 1/2” aluminium strip, cut in two, shorter piece about 6”, longer piece at least 12”. Drill a hole in one end of each to take a spring-loaded bolt, as shown.

To make a mask for redecorating a circular line on a plate:

Use the tool shown above to measure the angle of the plate dishing where the masking is required – this unfortunately usually has to be done on the back of the dish! Now use the school protractor to measure the angle – in this illustration, 23 degrees.


Measure the diameter (2r) of the circle which is to be masked on the plate straight across the dishing, in this example 8.8”. Use “scientific” calculator to divide this by the cosine of the angle: (if you did trigonometry at school, it's 2r/cosθ you want)

Keystrokes would be : [23] [cos] [M+] [C] [8.8] [÷] [MR] [ =] and the answer should be 9.559......etc. Or 9.6 in practical terms. Because of the dishing, the cutting diameter is always larger than the diameter of the circle measured directly across the dish.

Now spread some cling window film (face up, with its backing still on) on a stout piece of cardboard or a cutting board, and immobilise it with a heavy weight or two, or some masking tape. Set the circle cutter to 9.6” on its scale (this will actually be a 4.8” radius), remove the knife guard, and cut an arc longer than the length needed for masking. You can now make the mask by cutting out a piece of film from each side of the circular cut (using a modelling knife for example), and applying it carefully to each side of the circular line on the plate to be decorated. Use disposable gloves to avoid putting finger marks on any of the surfaces, and press down well so that paint doesn't creep underneath the edges.

The film should be flexible enough to take in the width of the line, but your first attempts may produce curve which doesn't fit – because of the uncertainties in measuring the angle. The quickest thing to do is to make a guess with the setting of the circle cutter and try again.


The Work Cabinet




I made my own work cabinet, and so can you if you are handy enough to be seriously contemplating ceramic restoration in the first place. Mine is made out of ordinary white chipboard, joined together with fixing blocks, and is 24 inches high and wide, by 15 inches deep. This is enough to accommodate at least 90% of the workpieces, together with immediate tools; only a few large pieces may not fit in and need to be worked on in the open. It sits on a cheap study desk, and there is room around and on top of it, and in the drawers, to accommodate all tools and equipment needed for a job within easy reach. On top of it are a couple of carrying handles. On the back of it is a small extractor fan inside a box to which a flexible hose is connected (vacuum cleaner hose) which can be hung out of a convenient window when air-brushing. Inside the back is a removable mirror, which is sometimes convenient to see round a workpiece, and which helps to distribute the lighting. On the inside bottom, I put a piece of wall lining paper, which has to be changed regularly, like babies' nappies. On the top front there us a 4-inch piece of plywood simply to shade my eyes from the lighting system. It is removable to allow replacement of the striplight tube.

I was fortunate enough in setting this up to have a window facing north just behind the cabinet, which is very valuable for a source of good daylight for colour matching, plus convenient air extraction and ventilation. Daylight is not always available in sufficient quantities even so; therefore I needed an elaborate lighting system inside the cabinet.



If I were making a new cabinet today, I might look to these suppliers for good colour matching lamps:

GTI Graphic Technology Inc. (look for Color Matching Lamps) and probably install 3 off F15T8/CM65 or F15T8/CM50 18” tubes, total 45 watts. They come in six-packs, which provides a stock of replacements. They have a UK distributor:

Graphic Technology [UK] Ltd who can no doubt advise on voltages, fittings and suchlike, because the USA are inclined to work on 110-120V and different plugs, fittings etc.

There are two standards for daylight colour matching lights:

CM50 refers to a colour temperature of 5000C, and is used for photography, paper printing and the graphic arts.

CM65 refers to a colour temperature of 6500C, and is used for paint, plastics, textiles, cars and industrial products generally. Since ceramics are clearly industrial products, this is the one I seek to use.



What I actually have in my cabinet is:

2 off Prolite Energy Saving Ultra Mini Spiral 20W Daylight (6500C) Bulb BC (100W Alternative) from BLT Direct These are my regular working lamps, and they provide a fair approximation to daylight, and a good strong light (about 200W old-style equivalent) without generating an intolerable amount of heat.

1 off 60w old-style pearl incandescent bulb.

1 off 60w old-style blue “daylight” incandescent bulb e.g. “Crompton - Craft Lamp 60w ES Daylight Simulation” (available e-bay, craft shops. These give quite good colour matching, but the light output is too low for this work.

These last two may be obtained from TLC Electrical supplies direct . I use them to check for Metameric colour matches by switching quickly from one to the other.

1 off 13watt 18” T5 (15mm diam.) striplight fluorescent tube. Colour does not matter; this is solely used to provide a line of light to reflect from a shiny surface (mirror reflectance, a.k.a. specular reflectance) in order to check for uneveness, and to help in air-brushing ground shades, where you are painting an identical colour.


You can see these in the illustration taken from the bottom of the cabinet, and also where the extraction fan is mounted.


Extra support for missing parts:


Sheet Metal - Copper sheet 0.1mm thick; jewellers' tinsnips from http://modelshop.co.uk/ for leaves, petals and the like. 0.05 to 3mm avaliable.


Wire: Fuse wire (15 Amp is good) for fingers, flower stems etc. - from your local electrical goods shop

Solid copper wire from electric cable, from DIY stores. This is not the flex that connects your computer to the mains, it is the flat grey cable used for wiring your house. Inside the grey PVC outer layer, you will find three solid copper wires, one is bare for the earth wire, and the other two are live (brown) and neutral (blue). The cable comes in various sizes depending on application, get a metre of the smallest size to start with! A wire-stripper is useful to get the insulation off.

Florists' wire is quite handy, from craft shops.

For really substantial jobs, consider using coathanger wire.

WireForm expanded aluminium is of use where square inches of a thick material need to be filled in! Also from http://modelshop.co.uk/





White Silicone Rubber for Casting - from http://hobby.uk.com/white-silicone-rubber-1000g.html



This is described as:

White Silicone Rubber RTV/NV Mould making compound. A two component compound similar to our "Silicone Rubber" items but, with a much lower heat resistance. It is a softer, more flexible compound for use where there are deeper undercuts and very fine detail. Can be used to make one or two part moulds. Suitable for use with resins, plaster and especially suitable for use with Alumilite. Complete with catalyst and instructions. Not suitable for use with white metal”

Full instructions are enclosed. It's a good idea to buy the Silicone Release Agent (illustrated) which goes with it.

This product gives excellent results, and moulds the finest detail. I did find it more convenient to use 1% catalyst instead of 2% (depending on ambient temperature) to avoid premature thickening; and then leave it overnight to cure. (For two-part moulds, use Vaseline as a release agent between the parts.)

There are any number of moulding compounds, silicone and otherwise, on the market, but I can think of no reason to look for any other.


Restoration Plaster (Gedeo brand)

Make up according to the instructions on the pack, in a disposable beaker. It make quite a thin pourable liquid. To get this safely into the mould, either use a pipette (for small amounts) or see How to pour for substantial castings. Sets well enough to demould in 1-2 hours: leave some in the beaker to see how it is doing.

In large moulds, the plaster may sink and leave a layer of water at the top: check for this before you de-mould, then if necessary pour it off, and top up with fresh plaster.

It makes a surprisingly hard casting, not unlike a low-fired bisque creamware. I have found it helpful, once it is fitted and shaped, to give it a coating of Araldite 2020, as an unabsorbent shell.

Available from craft and model shops, also check on Amazon/E-Bay.


There are many other plasters avaiable from Pebeo/Gedeo e.g. “Resin Plaster” “Hard Plaster” etc. which problably also do very well, but which I have not personally tried.



Dental Sticky Wax

This material can be melted in a small flame such as a gas lighter and used to seal round the edges of open mouldings. From Kemdent Ltd.



Dental Registration Wax

This material can be softened in warm water and used to take an open moulding of fairly simple items such as a pot rim. From Kemdent Ltd.



Godiva Modelling Wax

This material is very hard when cold, and very soft when heated in water about 50C. It is useful for taking detailed and small open mouldings. From Kemdent Ltd. , and Sylmasta



Copydex rubber Latex

Used in this context to make flexible open moulds, and Masking liquid . Buy in craft and DIY shops.



Oven types and curing times:


Araldite 2020: 80C for 30 to 45 minutes


Paints based on Chinaglaze:

50C for 15 minutes then

65C for 15 minutes then

80C for 15 minutes

The purpose if this slow rise in temperature is to allow any residual solvent to evaporate away, and to allow air inside porous materials to expand gently; putting a painted item straight into 80C often results in small bubbles forming under the paint, which results in having to do it all again.


A normal domestic electric oven (NOT a microwave!) with an internal fan and temperature control in Celsius is suitable for all purposes. The internal dimensions are usually limited to about 35 to 40cm in all directions, but this can be improved by putting larger pieces in at an angle, and/or removing the internal racks and backing plates, which support oven shelves. A fan helps to give even heating.


It's handy to put your workpiece on a baking tray ( reserved for that purpose – don't used it to make tray bakes at other times! ) perhaps with a bit of light cardboard under the workpiece, rather than bare metal. If you put paper under it, make sure the fan won't blow it against the workpiece and stick to paint or adhesive!


Some pieces will of course never fit in, and you just have to use adhesives and paints which do not need curing for these, which limits your options somewhat.


I have not used a gas oven, but I can think of no reason why it should not work as well.


ON NO ACCOUNT ATTEMPT TO USE A MICROWAVE OVEN. These cause uneven heating and are more likely to break your workpiece than mend it.


Chinaglaze


From Sylmasta at https://sylmasta.com/catalogue/product-category/glazing-materials/chinaglaze-system

Product Description:

“This low temperature glaze is perfectly clear, non-yellowing and has low odour during firing.

Low Temperature Chinaglaze is normally fired at 80°C (176°F) for just 30 minutes, to give an excellent hard gloss finish with high strength surface adhesion. Now available in White.”

You need white for a ground shade, though you can mix your own if you happen to have the right sort of mixe - see “B” white mixture.


Sylmasta also sell Chinaglaze Thinners, as it must be thinned substantially in order to be used in an airbrush. The thinner they supply is very expensive, and sending it to Northern Ireland raised it to a prohibitive cost. It appeared to be based on xylene, so I tried some on that from a local laboratory supplies firm, which turned out much less expensive and worked just as well. See Xylene.



[If you look up “Chinaglaze” on the web, you will see the name – also”China Glaze” associated with any number of nail polishes. I don't know of this is the same product]


Xylene

This is a solvent for Chinaglaze and will also work with Humbrol Paints and GlasArt Paints


I have always used “J T Baker's histo grade Xylene ref 3410” which is a purified (a.k.a. “analytical” grade) of “mixed isomers” . (There are three very slightly different types of xylene, called o-, m-, and p-, which are very difficult to separate, but don't need to be for this job!.) This particular grade seems to be no longer available. Bonnymans provide an industrial grade at a good price – http://www.bonnymans.co.uk/products/product.php?categoryID=1415&productID=6286 - also available via Amazon.


I prefer to use simple chemical substances which are well defined and of which I can check the hazard levels easily, rather than “Acme super-duper paint thinner” which tells me nothing, except that I am probably paying over the odds for it.

All solvents are hazardous to some degree (not excluding water!) and I preferred xylene as being one of the least hazardous which would do this job.... others, such as benzene and toluene (a.k.a. “cellulose thinners”) are carcinogenic to some degree, or are too volatile (such as acetone)

You can find a comprehensive guide to xylene and other chemicals at:

https://www.gov.uk/government/collections/chemical-hazards-compendium


My experience of it, over several years, is that if you work in reasonable ventilation (See The Work Cabinet ) , and wear spectacles or goggles, it does not cause a problem when airbrushing. You are much more likely to get some mild indisposition from skin contact, when you are cleaning your painting kit, unless you are wearing protective gloves, such as disposable nitrile (the blue ones). With me, working without gloves caused a slight malaise the following morning.

See also HEALTH and SAFETY Workwear


White Spirit

This is painter's white spirit, available in any paint shop or DIY store, and its main use is as a paint thinner and cleaner. It is not as strong as strong a solvent as xylene. It is inflammable like its close relative, paraffin oil. It is less volatile (dries slower) than xylene, so if you are using it for air brushing, be careful not to apply too much at a time, or you will get paint runs. For Humbrol colours, Humbrol Enamel Thinners is better for air brushing, but too expensive to use for cleaning!

It is the best solvent to use for brush painting with Humbrol and GlasArt colours, because (1) it does not dry too quickly (2) It is not a strong enough solvent to have much effect on an underlying cured Chinaglaze ground, so if you make an error in decoration, you can wipe it off again without taking off the ground colour as well. (There is a limit – in single figures - to the number of times you can do this)


Acetone

This is a strong thin volatile and highly inflammable solvent. Its principal use, other than as industrial solvent, is as a nail varnish remover, for which purpose it is usually mixed with unguents to avoid drying and irritating the ladies' skin. Be sure to get the pure stuff. Available in 50ml bottles from Boots (as a 'household solvent) or other pharmacies, or in litre quantities or more for E-bay. You don't need a lot of it, and because is is so volatile, once you have opened its container it has a tendency to disappear, slowly but surely, unless you have a very tight top on the bottle. 1 litre at a time is enough to be going on with.

You may use it for:

  1. Making up Milliput Dressing

  2. Making up (or removing) Paraloid

  3. As a paint stripper when you realise that your redecoration on your workpiece is fubar.



Disposal of Solvents and Waste Paint

It's not a good idea to put this stuff down drains – you will clog them! Don't attempt to burn it either – it will produce large amounts of black smoke! The least environmentally harmful way is to keep an old biscuit tin (with the lid off) in a garage or outhouse, pour the waste into it and let it evaporate. It would all be evaporating into the air anyway, sooner or later.

When the biscuit tin is well filled and dried out, bin it, and buy some more biscuits.


B” white mixture.

(So-called because I tried various recipes called A, B, C etc.; “B” was best)

Weigh into a glass jar with a well-fitting screw-top lid (A 250ml jam jar with a plastic seal ring in the lid will do very well):

50 g Chinaglaze

15 g Titanium Dioxide

100ml Xylene

and

about 100 4mm loose ball bearings (available in most bicycle shops, or on E-bay)

or pro rata according to the size of the jar.


An improvised ball mill makes a good smooth paint:-

I sealed the jar and attached it to a Kenwood Chef mixer dough hook with a lot of masking tape, then set the mixer and assembly on its back (so that the jar would rotate a bit off its axis), and the speed to its lowest, about 60 rpm. and let it run for 3-4 hours. A Kenwood Chef is quite expensive; but it's cheaper than any sort of a ball mill that I can find; you may be able to find a second-hand one, and you can also use it to make cakes and suchlike.

When finished, leave the balls in there; they help when you have to stir the mixture up to use it, and you can just add more of the same three components and mix again when you need more.

One of the nice things about this mix – though it settles out - is that it never sets really hard at room temperature, so you can always


Clear Glaze using Chinaglaze

In a glass jar with a well-fitting screw top lid:

50g Chinaglaze

200 ml Xylene

Stir.

This is about as thick as it is possible to use it with an air brush


Humbrol Enamel Paints

I recommend the following from the gloss paint range:

Yellow 69, Orange 18, Red 19, Violet 68, Blue 14, Dark Blue 15, Green 2, Brown 9, Dark Brown 10, Black 21, White 22, Glaze 35

Available from most model and craft shops, E-bay, Amazon. Shop around for the best prices. The exact colour names vary, if in doubt go by the numbers, which have no logic to them. The paint comes in 14ml 'tinlets' and also in a 50ml size, but I have found 50ml to be uneconomical because you are only using a few drops at a time; the 50ml size has been opened and shut too often, and gets skinned and the lid clogged before all the paint gets used.

These are all gloss paints; add Fumed Silica (Matting Grade) for matt effects.

It's worth getting 125ml of Humbrol Enamel Thinners for use in air brushing; for ordinary brush application and all cleaning, use White Spirit


Notes on colour matching with Humbrol:

White 22 is very slightly yellow and gets more yellow over time, not good as a ground shade, but use it to produce lighter shades of all the other colours.

Violet 68 is not a good mixer with Red 19 or Blue14; it produces very dull shades. GlasArt Violet 451 works better with these colours.

If a colour is too bright and needs dulled, Dark Brown 10 is often better to use than Black 21. To match blacks exactly, a mixture of these two is often best.

Dark Blue 15 is probably made from Prussian Blue pigment, which is a transparent colour unlike the rest and is best used on its own or with yellow or brown for very dark greens.

Both Blues are seriously Metameric with Chinese cobalt blue, as are nearly all blues you can find.. See under GlasArt Paints for a non-metameric mixture.

Glaze 35 is a yellowish-brown colour; if you need something more pale grey, add a tiny drop (on the end of a cocktail stick) of GlasArt Violet 451.


You will sometimes find that the Humbrol paint does not give a deep enough colour to match a colour on your workpiece, and adding black or dark brown just makes it dull. In such a case, add GlasArt paint of a similar hue to the Humbrol.


GlasArt Paints

From your nearest artists' supplier, or from Artifolk, Curtis Ward, E-bay, Amazon in 15ml or 50ml bottles. As with Humbrol, 15ml is more useful. The shelf life is limited if they are opened and exposed to air frequently; they eventually degrade to a useless gel.


Make sure to get the transparent colours:

Lemon 421, Yellow 420, Vermilion 436, Bordeaux 434, Violet 451, Dark Ultramarine 455, Turquoise 498, Brown 440, (Black 473, Clear 400 complete the range but you can use Humbrol for these shades) These are all glossy transparent paints and may be applied from White Spirit and mixed freely with Humbrol Paints.

Their principal uses in this context are:


Fumed Silica (Matting Grade)

Use GASIL 23 available from Conservation Resources

This is much finer than filling grade (Cab-O-Sil) and can be safely mixed with paint for air-brushing.


Metallic Paints

There are a lot of metallic paints on the market, and some look quite good. Our paint needs to be:

A lot of the stuff you buy in craft shops is made with soft media like paraffin wax, and looks very nice, but not for long. The metallic enamel paints, like Humbrol and Revell, are fast, but often dull and coarse-grained.

The best off-the-shelf paints I have found for this job are the Sylmasta Ultimate Gold range; four golds plus silver available from Sylmasta: https://sylmasta.com/catalogue/product-category/paints/

For most purposes I used a mixture of European Gold (~ 4 parts) and Pale Gold (~1 part), thinned with xylene for application by airbrush, or paintbrush. These two blend well to give a range of shades. For the other two, Antique Gold is useful as a bronze shade; English Fine Gold is the best for colour but is too coarse for my liking. They all dry hard, without needing any protective coat, and give as smooth and bright a gold paint as you are likely to find.

Gilded items which have been around for a while have generally dulled a little, because pure gold is a very soft metal and it is applied on to the very top of the glaze. It has no protection, so that any handling or wiping takes the pristine shine off it before long. (Because it is extremely thin, typically 0.2 micrometres, much handling soon takes it all off.) A new layer of real gold often does not blend well with the slightly worn look of many items. I found the above mixture generally hits the necessary mark in this respect.

The Sylmasta golds have an application problem for me inasmuch as they are applied from a xylene solvent and often need to be applied on top of previous decoration – BUT:

You can't successfully apply a xylene solvent paint:

If this happens, the whole thing needs stripped off and repainted. The safest way to do this is to apply it on top of an uncured ground (which can absorb a little solvent more easily) by using an airbrush: apply this slowly and carefully so that the applied solvent has time to evaporate. The airbrush always helps to ensure a bright and even application. See Example 7 Porcelain Gilded Vase for details.

I improvised a mixture which worked surprisingly well for brush application on all painted surfaces:

Roughly equal parts of :

Revell Gold Metallic paint 94

The “ink” from a PILOT GOLD MARKER pen

Revell” is a range similar to Humbrol; I don't normally use it because it dries rather too fast. Gold 94 is a better shade than the Humbrol offering, but it is too coarse-textured to use on its own. The gold marker ink is bright and smooth and probably based on paraffin wax or similar and wipes off quite easily. The mixture manages to combine the desirable proprieties of both; it has the fastness of the paint and much of the bright smoothness of the ink, and is just the right shade. You extract the necessary few drops of the ink by working the pen tip up and down on a hard surface, or by breaking it open when this doesn't work. I never got round to finding the source of this 'ink', or a more conventional 'craft' paint to serve the same purpose, since I used only very little; no doubt some ingenious reader can carry out the necessary research.


Metameric colours; metamerism

It happens sometimes that paint mixtures which are a good match to a colour on your workpiece by daylight, don't match well under artificial light – especially under old-style incandescent filament bulbs! This has the effect of showing up in artificial light like a badly-painted restoration. It is called metamerism, and the reason for it is very technical, so I shall not attempt to explain it here; it happens in all sorts of colour matching, not just on ceramics. (If you want technicalities, see: http://www2.cmp.uea.ac.uk/Research/compvis/CGmainMetamerism.htm )

The one which causes most trouble to ceramic restorers is cobalt blue, which is widely used on Chinese ware. If you match this with any regular blue paint ( including genuine cobalt blue powder pigment) and have got a good match in daylight, then under incandescent light it will look a lot more red in shade than the blue on the porcelain.

A mixture which gets round this is GlasArt Turquoise with GlasArt Violet; using typically 2 to 4 parts of violet to one of turquoise. This give a rather dull blue, which (it so happens) is just what you need to match the blue you find on Chinese porcelain. If it needs to be still duller, add a little black. The otherwise excellent GlasArt Ultramarine (dulled with a little black) cannot generally be used for this application, because of its metamerism.

Modern fluorescent and LED lights cause less of a problem than incandescent bulbs. I have an old 60 watt incandescent bulb in my work cabinet for the specific purpose of checking for metamerism.

In my experience, colours which I have used other than blues, are not metameric enough to be a problem. But it's a good idea to check, especially for ground colours. There is no technique for solving this problem other than trying out different mixtures – as with the recipe below:


Chinese Blue recipe for deep cobalt blue on oriental and Moorcroft ware:

1 drop Humbrol Blue 14 (for opacity).

2 drops GlasArt Turquoise

4 drops GlasArt Violet

(or pro rata, and adjust as needed to match!)

- in Xylene

Apply preferably by airbrush and glaze with Chinaglaze in xylene; allow to dry and apply a second coat of glaze if there is any dullness in the finish. Dry and cure.


Masking

Unless your workpiece has no decoration or very little, you will probably need to protect areas of decoration when you are applying the ground colour using the airbrush: this is called masking.

If you have done any home decoration, you will be familiar with masking tape. This is a self-adhesive tape which can be removed easily without damaging the underlying surface, and which is also sufficiently resistant to most paints and solvents. Ordinary masking tape has a slightly uneven surface which makes it too coarse for use in ceramic decoration; the edge leaves a very slightly ragged line. I have used three methods, depending on the job:

1. PVC electrical insulating tape is very suitable for masking the original surface of an ungilded workpiece, (which may have been restored with Milliput etc.) for its first ground painting. It comes in several colours, but black is probably the most common, and is highly visible on your workpiece. It is flexible to the extent that it can be made to follow moderately curved lines, like the lines round the rim of a bowl or the edge of a large plate. But the adhesive on this tape, and on any similar sticky material, is strong enough for there to be a chance that it will lift off (a) original gilding (b) any paint, cured or otherwise, which you have already applied. It would probably lift off only tiny patches, but this is enough to ruin the job. So you need something a bit less tacky.

2. Static Cling Window Film is very useful material for circular lines on the edges of plates, and re-usable stencils. This is similar to domestic cling film, but thicker, so that it is easy to cut to a shape. You can get clear film, frosted film or coloured opaque film. It comes with a backing paper which makes it easy to handle and cut. It is very safe on painted surfaces and on gilding. Don't confuse it with sticky-back film, which is essentially the same as the insulation tape I described above. (The most familiar application of the clear static cling film was until a few years ago, tax disk holders for cars.)

If you use completely clear colourless film, it is hard to see the edge when you are positioning it; if you use opaque film, it's hard to see what is underneath it, which may be important. The Über-Film opaque yellow is fairly translucent and can be used, but the best compromise in my opinion is colourless frosted film.

This is available from B&Q as D-C-Fix Frosted Static Cling Window Film” -they also do clear film. E-Bay sites sell clear colourless and opaque coloured film (brand Über-Film)

To use it as mask for a repeating pattern apply a piece of film over a fair example of the pattern, and either trace the outline using a ball-pen for cutting later (and remove any ball-pen ink), or cut directly with a modelling knife if it is unlikely to harm the surface (but then it blunts the modelling knife!)

To use it as a mask for circular lines on the edge of plates etc. , see detailed instructions under Circle Cutter “Xcut”

When handling the film, it's best to use disposable gloves to prevent finger-prints contaminating the surface: always make sure that the film and the workpiece are as clean as possible, and press them together firmly. If in doubt, after removing gloves, press edges down with the back of a fingernail. Stencils for re-use need to be thoroughly cleaned after each use.

3. Masking liquid recipe:

Mars Violet pigment 0.5g Weigh into a clean 15ml screw-top glass jar, and paste with

Water 2.5 ml then add

Copydex 7.5 g and mix. Keep jar sealed well.

This mixture may deteriorate over some months, so don't make up a lot. A similar product off-the-shelf is Humbrol Maskol ( http://hobby.uk.com/catalogsearch/result/?q=maskol&x=3&y=13) which is OK but a bit light in colour, so it's easy to miss small bits when you have to remove it.

This type of masking material, when it has dried, clings to nearly any smooth surface, but does not stick to it. But two pieces of dried masking will stick to each other instantly and firmly.

Application: paint it on with a small circular brush (an old worn one will do very well). Avoid repainting edges; you may pull off a sliver of masking which has dried at the edge! Do NOT clean the brush afterwards but leave it to dry (!). Allow the mask to dry completely before applying paint; it dries to a deep brown which is easy to see. Remove the masking as soon as possible after applying the ground paint, while the paint is still wet, by touching an unpainted bit of the mask with the brush, which should be still covered with a dried blob of masking material. The dried material on the brush will stick firmly to the dried mask on the workpiece, and with luck (and a lot of gentle stretching) the mask will pull clean off. You may now clean the brush (if you wish) by pulling the gathered masking material off with your fingers.

Problems: If there are small masked areas completely covered in paint, poke them with a cocktail stick to expose the masking, then they can often be lifted off with the cocktail stick itself.

Under heavily painted areas, the edge of the masking may dissolve to some extent in xylene solvent, especially if there is delay in removing the masking This leaves a dirty edge which can generally be cleaned up with a fine liner brush dipped in xylene.

If the paint is allowed to dry before the masking is removed, some of the paint may get pulled off with the adjacent masking.


4. Temp Maskingit's often possible to use a piece of cardboard held in the other hand (or by an assistant) to shield adjacent parts from over-spray – e.g. as in the legs of the horse in Example 5 Beswick horse and rider. The temp mask need not necessarily be in contact with the wokpiece.


With any sort of masking, bad edges can usually be fixed with a fine liner brush, either to remove paint which shouldn't be there using the solvent, or to apply paint which should.


Paint Brushes

It's best to use brushes with synthetic bristles for decoration using paints based on white spirit and xylene.

You will need mainly the smallest sizes, from 0 down to 10

I keep my brushes in 4 jars, bristles upwards: Virgin (out of the shop) Good (used a few times, undamaged) Poor (splayed bristles, useful for some rough jobs) Mixers (hopeless; useful only for paint mixing on a pallette. (Do not mix you paint with your painting brush! - if you want then to last a while)


My favouite brushes:

The ProArte Polar Round White Nylon Series 31 brushes, sizes 0000 up to 2 (they go up to size 16, but you don't need that much) are good general purpose brushes.

The ProArte Prolene (polyester) series 107 spotting brushes (0000 up 00) for spots of course

The ProArte Prolene (polyester) series 9 liners (extra fine size) - occasionally useful for long lines on the turntable

The ProArte Miniature Painting series 10/0, 5/0, 3/0 are best for the finest detail; I find the triangular grip a help.


Royal (or Royal and Langnickle..) Crafter's Choice are often found in shops in similar sizes; they have good non-slip grips and are inexpensive.


Flat brushes have limited use; a long ¼ inch flat (synthetic fibre) brush is handy for mixing ground colours. Sometimes a ¼ inch Polar Nylon Flat is useful for applying glaze over Humbrol or GlasArt decoration.


Always clean your brushes immediately after use, in xylene or white spirit accordingly. Rinse in a small jar, and wipe from handle towards the tip onto clean white kitchen paper, and repeat till clean. Store them in a jar, point up..



INDEX

Acetone

Adhesives And Applications

Airbrush and Compressor

Airbrush Maintenance

Applying the ground shade

Araldite 2020

Araldite 2020 Application

Araldite Instant

Araldite Instant Application

Araldite Standard

Araldite Standard Applicationn

“B” white mixture

BEFORE YOU BEGIN

Beakers

Bleaching

Brush Application problems

Chinaglaze

Chinese Blue

Circle Cutter “Xcut”

Circular Lines

Cleaning And Stain Removal

Clear Glaze using Chinaglaze

Colour mixing – an introduction

Copydex

Cyanoacrylate application

Decoration

Dental Registration Wax

Dental Sticky Wax

Dirty Cracks

Dismantling

Dismantling with Paint Stripper

Disposable palettes

Disposal of Solvents

EQUIPMENT MATERIALS and TOOLS

Emery or Silicon Carbide Paper

Example 1 Royal Doulton Figurine

Example 2 Chinese porcelain plate

Example 3 Heubeck bisque figurine

Example 4 Satsuma biscuit jar

Example 5 Beswick horse and rider

Example 6 Two Beleek First Period Jardinières

Example 7 Porcelain Gilded Vase

Examples Of Restoration

Extra support

Final Inspection

Finger Painting

Full Moulding and Casting

Fumed Silica (Filling Grade)

Fumed Silica (Matting Grade)

GlasArt Paints

Glass Paper

Glazing and getting rid of over-spray

Godiva Modelling Wax

Ground shade painting

HEALTH and SAFETY Workwear

How to pour

How to use Araldite 2020

How to use Araldite Instant

How to use Araldite Standard

Humbrol Paints

INDEX

INTRODUCTION

Inspection Recording And Pricing

Larger missing pieces

Magnifiers

Masking

Masking liquid

Means of support

Medium mix

Metallic Paints

Metameric

MicroMesh AO polishing cloths

Microbrush Superfine

Milliput Application

Milliput Dressing

Milliput Superfine White

Mini-drill

Mixing dish for ground colours

Modelling and casting missing parts

Moorcroft

OVERVIEW of CERAMICS

Oven types and curing times

PAINTING and DECORATION

Paint Brush Decoration

Paint Brushes

Paint Ranges for Ceramics

Paraloid

Paste mix

Pipettes

Powder pigments

Principles of Assembly

Properties of paint

REACT cyanoacrylate (THIN)

Restoration Plaster

STAGES in REPAIR and RESTORATION

Scales

Shaded Effects

Silicone Rubber for Casting

Small hand tools

Smoothing Joins And Filling Chips

Static Cling Window Film

Tacking with superglue

THE WORKSHOP

Textile Cleaning gun

The Ground Shade

The Work Cabinet

White Spirit

Thick mix

Thin mix

Tin Glaze Ware

Titanium White

Toners for Chinaglaze

Trimming to shape

Turntable

Ultrabrush Regular

Washing

White Spirit

Xylene

END