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07 31st, 2009| 
Let the repaired piece cool down completely and then soak it in water to remove the gummed strips. There will be some spots of adhesive along the join squeezed out when the jour was made and deliberately not wiped away. Rub the spots very carefully with glass paper and break them down before removing them with a scalpel or a razor blade. This cleaning is quite a delicate operation and if done without abrasion may result in lifting little chips of china or
glaze.
If the crack was also c’., Red and Aralditc with colouring was used, tidy the filled chips with fine glass paper, and over-paint or glaze if necessary.
Moulding aped Modelling whole pieces of a pot or a
figure are missing, the gap can be filled by rebuilding the piece with epoxy resin composition filler. But it isn’t quite so simple as that! Perfectly satisfactory pieces for plates, vases, bowls, statuettes etc. can be moulded or modelled and simply stuck into place provided the piece is not going into domestic use, but such mends are not strong
g enough
to withstand hard wear for very long unless they are sup- ported by metal cores or pins. It is easy to mould or model a jug handle without a core, but unlikely that it will last very long if the jug is used. If the new handle has a core it will be very strong indeed. The making of cores and pins is described in a later section, and here I shall talk about moulding and modelling without supports. The techniques involved are almost identical when supports are incorporated. The job requires only a few cheap tools until the moment when you get involved in metal work and drilling for supports. And many people, once they reach this stage, just take the work to an expert restorer rather than buy drills and bits etc.
Before mending a piece such as a bowl or plate or vase, without using a core, scratch or file the broken edges so that the new piece of moulding will lock into the edge as it sets. The danger is that your new pieces may not adhere too well to the smooth and thin edge of a break without some kind of roughness in which to get a grip, as the problems of adhesion are not quite the same as those of sticking two edges, of porcelain or pottery together.
Next, a backing is necessary. This means a surface up against which you can press the filler to remake the piece. If the object is a flat plate, with : flat surface, the same gummed strip as is used for binding can just be stuck on the outside surface of the piece completely covering the broken area. As it dries it stretches tight and makes a good smooth surface up against which to press the filler. This gummed paper cannot be used on a curved surface because it pulls taut and flat across the curve as it dries. Therefore the mould will
wihave to be made with a flexible material which will take a curve. Plasticine does the job well, but it never sets hard and can be pushed out of shape rather easily. Wedge plasticine before use—this is a potter’s term meaning quite simply banging it until it has no air bubbles in it. A mallet or a wooden rolling pin make good bashers for plasticine.
If you use plasticine for the mould and Araldite for the filler you will have to get some cellulose acetate to use as a parting agent as the two react upon each other and must be separated by coating the surface of the plasticine which will come into contact with die filler.
There are other moulding materials. The dental impression compound Paribar is more expensive, but is quite excellent for the work, and is worth the extra money for it can be used again and again, needs no parting agent, and has other uses. Paribar is softened in hot water before use and resets fairly hard but is flexible enough to be extricated from quite deeply cut castings.
Making Moulds. Imagine that you have to replace a curved piece with a fluted surface, from the edge of a bowl. The whole of the edge of the bowl is fluted in the same way so you take an impression of a matching piece of the pattern oil a sound section of the edge. ‘Wet the surface of the bowl and press a slab of plasticine (about half an inch thick) on to a section just a little larger than the missing piece. Carry the plasticine up over the rim of the bowl so that it will be marked but don’t bend it too far round the rim if there is any ridge or it may be difficult to remove the plasticine without bending it. Press the plasticine well and truly until you are satisfied that you have made a perfect impression. Lift it carefully off and place it over the hole on the outside of the bowl in exactly the right place so that the pattern is continuous. Press it lightly so that the broken edges of the china mark the plasticine, then remove the plasticise, and paint the area inside the edge marks with cellulose acetate parting agent, then replace it over the hole. It will stick to the dry china round the edges of the break. Bend over the top sections of plasticine away from the hole, round the rim of the bowl to keep die mould in place. A few strips of Sellotape across it and on to the china will help. Don’t use gummed strip, for this will dry out and flatten the mould. The Scllotapc may give slightly but will help to avoid the disaster of the mould coming off the pot in the middle of die filling operation which follows.
Paribar can be used in exactly the same way to make a mould especially where there is a deeply indented pattern in the china. The Paribar goes hard, but it can be softened with swabs of boiling water and removed from die filler section without breaking it when the job is done. No parting agent is needed so that the Paribar can be put directly on to the break and left there.
Filler Composition and Filling. Now to mix up sonic filler (see Fillers and Cements). Araldite two-tube epoxy resin is first mixed together and then titanium dioxide (or other whitener) is added until the mixture has a nice doughy consistency. This mixture is a bit sticky and clings to tools and fingers. Keep a little dish of the powder handy, and another dish of Methylated spirits. Dip your fingers in the powder, and the tools in the Meths from time to time, and you won’t get so stuck up. When dried out this filler looks exactly like biscuit, or unglazed baked china and takes overpainting very well. It also sticks directly to the edges of the break and you should have no trouble in making a perfect join. It isn’t the easiest of jobs to make and handle this filler, but the result is so good that it is worth practicing to get the mixture of the right colour and consistency.
Kaolin mixed with Araldite in the same way makes a very stiff, not quite so sticky, more translucent and buff coloured filler, but it has the disadvantage of not sticking quite so well to the edges of broken china as does the first mixture.
Isopon polyester resin filler is a paste which is mixed with a hardener. It is excellent for filling big holes as it dries quickly, but this means also that you must be able to work quickly. When using Isopon make all inside mould of the break as well, and having filled the mould, put the second inside mould oil to the filler from the inside to get a smooth interior surface, pressing it down well. Isopon requires no parting agents. Although it will stick to itself so that it call be built up in layers, it will not stick to china, so when the moulds arc removed, the new Isopon piece will come away and will have to be stuck in just like an ordinary broken piece. It can be rubbed and filed to finish it off It cannot be used as an adhesive.
Bondapaste is another excellent filler which hardens quickly and does not have to be baked, nor does it require powder additions to make it opaque. It does not dry white, but this is immaterial if you are going to overpaint it any-way. It can be used as an adhesive or cement and when used as a filler it stays in place without further adhesives. It can be filed, carved and abraded within a quarter of an hour of use, so is a very time-saving material, once one is experienced enough to shape it quickly.
The exact consistency of any filler is difficult to describe and can only be discovered by trial and error. If it is too hard it will push the plasticise out of place as you press it into the mould. If it is too runny it will tend to run into the lower part of the mould in whichever place you are holding it, and will not make a piece of even thickness. If the mould is made of Paribar then a stiffer nix of filler can be used.
The mixture is worked into the aperture with a round ended tool. Boxwood potter’s modelling tools are excellent but many things make good modelling tools. Some workers like to prop the pot up as they work, others hold the pot in one hand so that the break with its mould is cupped and held in position while the filler is worked in. Great care must be taken to make sure that the filler goes into all the corners and crevices right up to the edges, with no air bubbles trapped underneath. Smooth the inside surface with the tool and with thumbs and fingers until it is as like the surrounding inside surface as your eye can judge. Setthe pot aside for an hour, if the filler is Araldite, by which time it will have set to a rubbery consistency and can be worked further if necessary. If a quicker setting filler has been used, once it has set hard it can be carved, filed and abraded until it is absolutely perfect, and it is then ready for overpainting.
To speed up the setting of a mend done with Araldite, bake the pot for half an hour at zoo deg. F. If there are any small cracks or pits in the surface fill them with a thin mixture of filler, using a water-colour brush.
Chips. The mending of chips, big and small, which do not go right through a piece, involves work which is halfway between the filling of apertures as described above, and modelling
which is described in the next section.
Quite simply, you make up a mixture of any of the above mentioned fillers into a fairly stiff mixture and press it into the previously cleaned and dried area of the chip and smooth it until it looks right. Don’t get air bubbles under the filling. Wheel chips—large chips on the edge of a piece—should first have a thin layer of adhesive, to help bind the filler in place. The art of filling chips is to get a good blend along the edges and to get the filling neither too proud nor too shallow, and in getting the composition in so that no air bubbles remain behind to raise it in due course. If you suspect that a little air is trapped, prick the filler with a pin and press it down again and fill tip the pin hole.
Allow the filler to dry out over a hot radiator and then, when it is hard, rub it down with glass paper until you are satisfied that the chip, after overpainting, will be indistinguishable. Pick up the piece and squint at it at eye level in all possible planes, and rely on the sensitive tips of your fingers run across the mend to detect any irregularities. If even at this late stage the chip is not properly filled, more composition can be added for it will stick to itself, and the process repeated until you are satisfied.
Modelling. When neither straightforward sticking, nor press moulding can be used to mend an object, try modelling. It is impossible to make a mould for a missing piece which is not a repetition of another part of the object, as described previously. The missing piece just has to be built up from scratch and the result depends on the artistic ability of the restorer. Large modelled sections will have to have metal supports—dowels, or pins, or strips—and the techniques will be described later on. I am still concerned with the techniques which do not include drilling.
When a part of a plate, or a vase, or perhaps a lid knob must be remodelled, take a piece of rather doughy filler composition and roll it either flat for a flat section, or into a ball for a knob, or into a sausage for a handle, in an approximate size and shape for the job. Then press it firmly to the edge of the broken part, and model it with Boxwood tools, fingers and any suitable home made tools that you may fancy. Whenever epoxy resin mixtures are being used, dip the tools in methylated spirit to avoid sticking.
Modelling becomes really interesting when a porcelain object such as a figure or perhaps a vase festooned with flowers and leaves has pieces chipped out or broken off and lost. To remake flowers and leaves is not at all difficult. Any woman who has ever made an apple pie with a decorated crust knows the technique. The pastry, in this case filler composition in a nice doughy mixture, is rolled out to the thickness of the petal or leaf required and then pieces are cut out of it in the flat. A small sharp knife or scalpel can be used as a cutter, shapes having been first marked out with a darning needle or a fine graver. Or, if the leaf or petal pattern is to be repetitive, a cutter can be made out of strip brass or copper foil, beret to make the appropriate shapes. Make a template or pattern out of plywood, using a fretsaw (see Fig. 8). Tack this pattern to your work bench with a central nail and then hammer a copper foil strip round it with a small hammer until it is exactly the same shape. If the template is pinned with a central nail it can be pivoted round as the cutter is being made so that all pieces can be reached.
The cutting of different species of flowers, daisies, roses, apple blossom etc. is hard to describe exactly. It is a matter of careful observation of thepetals which are to be matched, and of measurements with calipers and dividers, if your eye is not good enough. Petals are cut out in flat shapes and bent over slightly at the edges, and rolled into concave shapes etc. Once your petals and leaves arc made they are then fixed to each other and to the main piece, and there is no great difficulty about this unless the anchorage point is very small indeed, especially if you arc using a good adhesive filler composition such as Araldite and titanium dioxide. it is often possible to add an extra leaf, or to put in
small
a smasupport of composition disguised in some way as part of the decoration, which will hold the modelled part in place. Most people have a collection of tools for modelling which they have made specially to get into different corners ; sewing needles, bent knitting needles, scalpels, spatulas, rifflers, spikes and blades of all kinds, even old hacksaw blades, conic in usefid.
When pieces of an object are missing for which no pressed mould can be made, it is still possible to make a mould out of plasticise which approximates pretty closely the missing piece, and to put this on to the whole in such a way that the aperture can be filled with composition in exactly the same way as a pressed mould is filled. Then the new piece must be rubbed and shaped to final perfection after the setting or baking process has been completed; but
this can be a slow job.
There are problems when it comes to modelling difficult things like faces; it rather depends upon how clever you are, but there is yet one more way, which involves modelling. It is a much more complex and tricky job, but it can save such a lot of time and trouble in the long run, -aid once again may enable you to get away with it without resorting to pinning and dowelling.
Make a model, in plasticine, of the missing part. Actually this is easy if you have a talent for modelling, terribly difficult if you haven’t. Say for instance that half a leg and a foot are missing from a figurine. Using calipers and dividers, measure the other leg and foot exactly, so that at any rate lie won’t have a size six left boot and a size ten right boot. Then model a plasticine leg to the right diniensions and in the kind of position in which it looks as if it ought to be, and keep trying your model in the space until it satisfies you. Plasticine doesn’t harden so take as long as you like over making the model.
Having made your plasticine model, a mould must be made from it and a cast or pressing taken from the mould. The finished cast can simply be stuck into position (or dowelled or pinned if necessary).
Take a sheet of glass, and a large lump of plasticise. Roll the plasticise out into a very thick strip and lay it on edge on the glass (see Fig. 9) in a square or a circle plenty big enough to hold the model, horizontally. Then fix the model, horizontally, halfway up one side of the container that you have just made. A peg carefully inserted into the end of the model and pushed out through the container side should hold it into position. Then prepare some plaster of Paris. Into another container which can be handled easily and has a pouring lip, put enough water to half fill the mould container, and sift plaster of Paris powder into it until the mixture is the consistency of thick cream, stirring with the hand to break up lumps. Then pour the plaster of Paris mixture into the mould until it is halfway up the model. Leave the whole thing to set. Then cut two wide grooves or shallow holes out of the plaster.
sure that it is really well drenched and that no tiny part has escaped swabbing. This acts as a parting agent between the two halves of the plaster mould. Make another mix of plaster as before and pour this nito the mould until the model is well covered. When this has set, remove the plasticine case and case the two sections of the casting apart. Take out the original plasticine model and you should have a perfect mould in two halves. This mould will have two locking pieces where you cut the grooves or shallow holes so that when the two halves are put together again they will locate exactly, and at the end where the model was attached to the side wall of the plasticine container, there will be a hole.
Now you have a mould which can be used to make a casting or pressing of your original model. Smear a film of silicone grease all over the pattern sections of the mould to prevent the filler sticking to the plaster of Paris, and then make up enough filler composition to fill the two halves of the mould. This filler should be soft enough to flow freely into the mould sections. When the two sections are filled, bring them together and bind them tightly with wire. Ram the composition well home, through the hole. Leave the mould, with the hole at the top, for two hours to set, and then, if you are using epoxy resin, bake it for half an hour at 2oo deg F.
Undo the wire binding and take off the plaster. If you have not used a parting agent, the plaster can be cut out and broken away and the last of it scrubbed off the model. Stick or dowel the finished model to the whole, having
made sure that the edges fit perfectly by filing and abrading. bradin,
Any discrepancy in fit which is too big to be put right by filing, can be filled with some filler composition.
Moulds can also be made from pieces of porcelain similar to the piece you are trying to replace, and then pressings made from these can be carved, filed, abraded, and built up to fit exactly.
Instead of plaster of Paris, rubberised solution such as Qualitex can be poured around your model. The advantage of using this material is that the mould is flexible and will come off difficult undercut models without damaging them. Rubberised solutions, therefore, are best for making moulds from models which must not be damaged in any way. The technique is much the same as that described above. A plasticine container is built up round half the part to be copied, and the solution is poured in.
The process is repeated on the other half and you then have the complete mould in two sections. Details vary with each job.
Faces on statuettes are very alike, and differ only iun detail of hair and headdress. There is no reason why, if you collect figures, you should not make a series of moulds or masks from any statuettes that come your way, and so build up a stock of faces iii reserve for the day when they may be needed.
Incidentally, the principles of making casts, moulds, pressings etc. are generally similar for work in all kinds of materials, and many restorers of objects other than china, such as old guns and pistols, make their own metal castings. It is a skill which has so many applications, not only for restoration but for creation. Modem materials make exciting castings and pressings, and it is an art well worth studying for its own sake.
CHINA AND GLASS
China restoration is always delicate work, requiring care, accuracy and knowledge of technique. How much knowledge depends entirely on how ambitious you arc. Most people, if they Fail in simple efforts to stick china together, take it to a professional restorer if the piece is of any value. It also depends on what is going to happen to a piece after it is mended. If it is to stand peacefully on a shelf, then the repair need not be so strong as it would have to be for domestic use. Some people try to restore a piece to the state where only a very close scrutiny will reveal the mend. It is technically possible to fool even ultra violet light. Others feel that there is no shame in a few cracks in old china. Like so many skills connected with making and mending things, china restoring can develop from the ability simply to stick broken pieces together, to the most complex dowelling and pinning and moulding and modelling and casting and painting. It can start by being a chore and end by being an art, which like any art develops into pride in craftsmanship, and pleasure in achievement. Maybe the kind of painstaking repair I am thinking of comes outside die scope of a book on restoring junk, but I shall include an outline of some of the methods and materials and tools needed just in case you do decide to venture further than a little bit of glucing.
Some technical colleges run classes on china restoration, but they arc few and far between, although this is one of the best ways to gain expert knowledge and experience. The study of books on die subject and plenty of practice should make you reasonably efficient if you are not totally ham-fisted !
There arc so many objects in so many shapes and sizes made of so in-uiy materials; so many ‘pots’ that it is difficult to detail all the techniques, and each job must be treated on its merits. The first and easiest method is to mend by sticking. Sticking things together used to be more difficult than it is now, because die old adhesives were nothing like so easy to use or so heat-and-water-resistant, so free from shrinkage, or attacks by fungus, so clean, so invisible, or so strong. The invention of cellulose glues and epoxy resin adhesives has completely revolutionised sticking, and made it possible to mend things with adhesive alone where riveting, dowelling, or pinning would once have been essential.
As a general rule, a piece of china, be it a plate, a pot, a Statuette, or a vase, can be mended by sticking alone if the two faces come together properly and neatly and if they can be made to stay in position while the adhesive is setting.
If a part such as a curved handle, or the limb of a figurine, is broken, perhaps in more than one place, and there are pieces missing; or if the surfaces to be joined are chipped and do not fit, or there arc whole sections missing; then more ambitious methods will have to be used. Whole sections can be remade by modelling with epoxy resins just as the sculptor models, or by making plaster moulds and taking castings. Large missing parts can be moulded or modelled incorporating wire supporting frameworks fixed to die whole piece.
Broken parts are refixed together and to the whole, provided they are thick enough to carry drilled holes, either by pinning—which means inserting a metal pin into a hole drilled after the pieces have been stuck—or by dowelling, which is the joining of pieces by drilling matching holes in each and cementing in a single dowel. Any or all of these methods might be necessary at the same time in one single object (see Fig. io).
Lastly, broken pieces can be riveted together. The ugliness of this technique, strong though it is, means that it has largely been superseded by other methods since the discovery of die better adhesives, and is really only used for extreme strength and utility rather than for restoration and beauty.
Cleaning. Before any porcelain or pottery may be mended it must be cleaned. Normally all that is needed is a wash in warm soapy water. If die piece is already clean, then wipe it with a piece of silk dipped in methylated spirits. Keep any old pieces of real silk for china restoration work, as silk does not leave little bits of lint or fluff caught on jagged edges.
Remove stains from china with very dilute hydrochloric acid, but test first in case the acid etches the glaze. A cloth dipped in either bicarbonate of soda or common salt will remove coffee stains.
To remove dirt along cracks which are not going to be repaired—cracks which are, and look dirty—make a pad of cotton wool and saturate it in a mild bleaching solution such as hydrogen peroxide and lay it along the crack for some days, renewing the solution as die pads dry out. When the treatment is completed, scrub the piece gently with a soft brush, and even more dirt may conic away. This method is useless on earthenware, but for this and for English porcelain, which is usually so porous that the dirt is well ingrained, soak the piece for up to a week in a solution of domestic bleach. This will remove most stubborn stains and won’t etch the glaze.
If china has been previously mended, the edges of the breaks may be very dirty, and sometimes glue remains which is invisible except under a magnifying glass. All edges must be cleaned, and you must be sure they fit together before going ahead with the next stages of the job. First of all soak the pieces in boiling water with pure detergent added. Remember, if there is another part of the object which has been mended and which you do not wish to do again, to keep it out of the water or it may melt apart. Glue, Seccotine, shellac and Durofix will come off in boiling water, and joins made with these adhesives will soften sufficiently to be parted. If this treatment does not tackle the old glue then you will have to get to work with the appropriate solvents (see Solvents). Methylated spirits will shift shellac that has resisted boiling water. Swabbing with cotton wool dipped in amyl acetate removes cellulose adhesives such as Durofix. Acetone removes cements, but may take some time about it. Dissolver is a new solvent which will shift many kinds of glues including Araldite, especially some of those used for glass repairs.
Literally to boil a piece in detergent and water is a last resort to remove stubborn adhesive without abrasion. Finally it may be necessary to pick away at the old adhesive with a scraper or even a needle. Obviously this has to be done with care.
If old rivets have to be removed, cut them in half with a needle file and pick out the bits using acetone to remove the cement if necessary.
The first two methods are done with just a few tools, but the moment you have to drill, more complex tools will be necessary, and this means more expense, and also more time spent on learning to handle the tools. China drilling is not difficult, but it takes a light hand and a steady one, and infinite care and patience.
A power drill, which is normal workshop equipment nowadays, can be used with the rightbits for a lot of drilling work provided it has both vertical and horizontal bench stands and operates at the right r.p.m. The ideal tool for most drilling is a dentist’s drill—in fact an electric motor with a. flexible drive and a hand-held drill at the end. But this is an expensive piece of equipment not justified unless a lot of work is to be done, so its use is not described here. A hand drill and appropriate bits will needed for starting holes, and for the awkward holes. A special twist drill with high gearing can be bought for work on china, and some people prefer this to the other types. It is good for dowelling and for work in substantial pieces, but is a little difficult to control on really delicate work.
Brass wire is used for pins and dowels, and unless you arc doing very complex work only one or two sizes will be needed. Other standard tools such as the hacksaw, and calipers you may already have. Small cramps and a pin vice are useful, and all shapes and sizes of small files and rasps, scalpels, and probes. Various materials will be needed for making moulds, supporting pieces while they dry, binding to aid adhesion etc. These I shall mention as they conic into use.
Sticking. There is some general information on adhesives wider that specific heading. Here I shall discuss the various methods used for mending china with adhesives.
Ordinary domestic two-tube Araldite (AV and HV roo) is suitable for all practical purposes for almost any work. It is best used in a well-warmed room, and pieces should always be warm when joined. Keep the tubes of Araldite warm before mixing. All this helps the adhesive to flow readily, and to grip. A cold unheated workshop is not a suitable place. Work in a heated room with a radiator with a flat top or heat conductive shelf above it so that pieces can be kept warm.
The second important point, already stressed several times, is that pieces must be clean and dry. Pieces that have been washed or boiled to clean them may take quite a long time to dry out, especially the unglazed edges of breaks. Damp, dirty surfaces just will not adhere.
Thirdly it is vital to grasp the basic principle of adhesion, whicl, is to bring the original faces as close together as is physically possible, with the thinnest practicable layer of adhesive between. The edges and surfaces of the break then lock together naturally. It is a misapprehension to suppose that thick layers of adhesive will make more successful joints. All the adhesive that is needed is enough to fill all the tiny gaps and crevises between the faces so that the two present smooth surfaces to each other with no air pockets, and they will adhere.
Lastly, stuck joints need to have some pressure exerted upon then, while the adhesive is setting, either by clamping the pieces together, or by putting a weight on top of a flat piece, or more usually by binding the pieces together with gum strip (not Sellotape) in such a way that pressure is exerted on the join.
The methods of applying this binding
g differ slightly
with every mend. Always use gummed strip, and buy a big roll at least il” wide. Cut this down if necessary. Strips are stuck as nearly as possible at right angles across joins such as simple breaks in a plate or vase. When thc join is rather more difficult, such as a broken vase handle or lid, the strip is stuck on so that it will exert pressure at right angles to the join. The wet gummed strip is easy to put into position, and as it dries it shrinks, holds fast to the china and so exerts pressure on the join. When you reach the stage of placing the prepared pieces together, wet the cut strips of paper thoroughly but remove any surplus drips of water with a swab. They should be damp right through but not dripping wet, as moisture will prevent pieces from adhering if any gets on to the broken edges. Sometimes it is best to pre-stick the strip on to one piece of the work (after you have warmed the piece for glucing, or the gunimed strip will dry out completely) and then put the two edges together. Draw tile loose piece of strip down smoothly and tightly across the join. A little bit of practice at binding diffi llcult shapes will teach you how best these paper bandages can be applied. Remember always that as the strip dries and tightens it must pull across at right angles to the join, so bringing the pieces together and holding them there. Use very long strips if necessary. Make a cross of strips, stand a pot in the middle and bring the ends right up over the top to hold it together. Small
small
pieces of strip may be needed across very joins to exert pressure (see Fig. 7). A binding applied like a puttee round and round an object is almost useless except to keep things in place. The same binding techniques will be used when mending by dowelling and pinning, as described later, and a little thought and study will help you to work out the details for each job. Very occasionally it is not possible to bind, to clamp, or to weight pieces together because of a peculiar shape or a break in an odd place. Make supports out of plasticise or wire to push pieces together, or at any rate to hold them in position while the adhesive sets. No tension is applied to the joint so this way isn’t that satisfactory, but it is better than nothing. Don’t let plasticise come into direct contact with Araldite or any epoxy resin, as the two will react together.
Having cleaned your porcelain or china ready for mending, next check whether or not all the pieces arc there, whether or not they fit together perfectly, and then decide upon your method of restoration. Pieces made of thin China ai-c almost impossible to dowel or pill as there is no thickness to take drilled holes. Hollow figures may need to be dowelled in the hollow sections, or by pinning. But if there are sufficient clean, close fitting edges which will contact nicely, sticking alone may be all that is needed. Details of dowelling and pinning follow, but here I deal with sticking on its own. A piece which has been broken into several pieces should be very carefully checked for fit before applying adhesive. If necessary make tip a kind of jig-saw puzzle, using Sellotape and fit the whole thing together. Be careful not to work yourself into an impossible corner by putting the pieces together iii such a way that i lie last piece cannot be got into place. This can happen, for instance, in a bowl where the break consists of two or more pieces which arc wider at the lower end than they are at the rim end. If a piece is in several fragments it is sometimes easier to stick two or three pieces together to make one large piece, and then join this to the main piece. So do take a bit of thought, and be sure that you have solved the puzzle before taking any irrevocable steps (see Fig. io).
If, as well as being in several pieces, the pot has a Chunk missing, it will be necessary to mould a new piece, but first of all any sticking must be done mid finished, and the Moulding is later carried out as a separate operation.
Having cleaned the pieces, dried them and checked for fit, warm them thoroughly. Prepare a small amount of adhesive, no more than you need, and apply it with a knife to one edge of the two pieces to be joined. Usually it is best and easiest to apply the adhesive to the piece rather than to the whole. Put adhesive on both edges only if the fit is not perfect, or if the material of which the pot is made is very heavy thick porous earthenware, which will absorb a lot of adhesive.
Then bring the two edges together as firmly as you possibly can. Obviously you don’t want to break the china again, but exert as much pressure as you dare on the join so that the adhesive comes squeezing out. If you want to remove adhesive in order to get a clear look at the join through a magnifying glass to make sure it is properly aligned, moisten a water colour brush in a little methylated spirit and take off a little adhesive with that. Do not take it right down to the join as this will weaken it. Surplus adhesive should not be removed along the join until after it has all set. Any adhesive which has escaped on to other as yet unmende8 broken edges, or on to gilt or lustre glaze on the pot, must be removed at once with the paint brush. On the broken edges it will prevent proper matching if it dries into a little lump, and it will lift gilt or lustre when it is finally removed.
H.M.G. adhesive can be used in conjunction with Araldite to make a fairly quick setting join, by putting H.M.G. on one surface of the join and Araldite on the other. The quicker drying H.M.G. binds with the Araldite and helps to hold the two pieces together while setting takes place.
Then the joins are bound with gummed strip as described above. The piece is put down and left to set. Epoxy resins, especially when the join has been properly strapped, will hold almost immediately, and the pieces will not move in relation to each other unless the joins are imperfect or unless the balance and weight of die pieces are such that gravity pulls them out of place. Plasticine supports, bowls of fine clean sand, bits of wood and wire, will all make supports and cradles. If the piece to be joined is some kind of figurine and not a plate or a bowl with flat or curved surfaces, parts sometimes have to be stuck on entirely by balance. The heads of small figures frequently get broken off, and ifyou intend to stick a head back without dowelling, the fit along the break will have to be perfect, and the figure itself must be held in a firm grip so that the head will balance in place while the adhesive sets. Bury the figure in a bowl of sand, with the broken edge set horizontally just above the level of the sand, and then balance the part on it. Move the buried section about until the broken-off piece balances perfectly upon it. Make sure all loose sand is brushed away from both edges, and then, using very fluid adhesive, anoint the broken edges. Carefully put the piece back into place, and allow it a few moments to adhere before delicately, and without moving the buried base, setting it perfectly into position.
It really is a matter of trial and error, and with a bit of ingenuity you can find a solution to every problem of sticking and binding and balancing.
The final process of sticking when using epoxy resin glues, is to harden the joins by baking. If an entire piece has to be moulded in, after some sticking has been done, it is still best to bake the first work for a short while before doing the moulding, just to make certain that the work which has been done is really firm. Baking can be omitted entirely if the piece can be left alone for a good long time to set.
Up to a point the heating of Araldite softens it, and if you leave a job for some hours before baking and a piece has slipped a little out of place, warm the join with boiling water swabs to soften the Araldite enough to move the piece back into position. Leave joins made with Araldite for a few hours before baking and then place the piece in the oven of an electric cooker or of a solid fuel cooker. Put an asbestos mat on the middle shelf and place the china carefully on that, and keep the oven at a temperature of Zoo deg. for about an hour. Over 3oo deg. the Araldite will darken and in any case the china may not stand it. If your oven has no thermometer, buy a small one. If it is impossible to keep the temperature of the oven steady,heat the oven, put in the piece, and switch the oven right off, leaving the piece there until the oven is cold.
Mending Cracks ivith Adhesive. So often articles crack without breaking. The cracks get dirty, and the piece when touched vibrates a little and does not ring true. It may, one feels, collapse into pieces at any moment. Cracks can be repaired quite effectively without completely breaking the pieces apart. Most forms of pottery and porcelain are to a small extent flexible, so carefully insert the edge of a razor blade and part the crack a little. Clean the crack as described above and make sure that the whole piece is thoroughly dry by standing it on a radiator until it is pretty warm. Heat the separate tubes of Aralditc to get them runny and make up a mix, with a little white colouring in it if there are any chips along the crack which need to be filled. Mix the Araldite on a warm surface and keep it warm while working. My own nightstore type electric radiators which have flat tops, are absolutely ideal for this work and I work directly on top of one. This is not recommended by the makers of nightstore radiators but who cares about that !
Prise the crack apart with the razor blade as far as is possible without breaking the piece completely. If the crack runs right to the rim or edge of the piece, slide the edges of the crack apart a little, one up and one down to expose some of the broken edge. Run the adhesive right into the crack, work it in with a finger if necessary, then move away from the radiator and press the edges tightly together. Wipe off any surplus adhesive with methylated spirits, but not that exactly along the crack. Put several pieces of gummed strip across the crack at right-angles on both sides of the piece, and leave the whole thing to dry (bake after an hour if you wish to) for half a day on the top of the radiator. This should set the adhesive perfectly.
