‘Contemporary Living’ at Christie’s South Kensington – Part 1

 

Miniature exhibits and 'push tools' from the interactive model 'The Patron's House' exhibited at Christie's during 'First Open' April 2017

I have just finished work on a particularly interesting, rewarding .. and of course demanding! .. piece commissioned by the London gallery The New Craftsmen for a showing of their artists’ work in conjunction with pieces from the Johannesburg based Southern Guild and items from Christie’s contemporary collection. The ‘exhibition’ .. along with my miniature, interactive version of it .. will be briefly open to the public at Christie’s South Kensington under the title ‘Contemporary Living’  from April 1-4 before the auction process starts. So yes, it opened already yesterday .. but it’s public tomorrow from 9.00 – 17.00 and on Tuesday 9.00 – 17.00, continuing 18.00 – 20.30 .. admission free!

The idea was to include a playful, dollshouse-related, interactive model within a showing of applied craftsmanship and artist/designer furniture .. so that visitors can actually rearrange the exhibits according to their own preferences. ‘The Patron’s House’, as it’s titled in the show, is really a more simplified, ‘toyed with’ version of the exhibition space, but opened out to allow more access.

'The Patron's House' Contemporary Living at Christies, April 2017

'The Patron's House' David Neat, Contemporary Living at Christie's, April 2017

The work had to be done relatively quickly .. there were more than forty individual objects and, within the realm of the model, each piece had to have its own plinth. This was mainly for practical reasons, so that the pieces can be moved around without harming the delicate models. From the beginning we felt that the plinths should be somehow decorated .. stark white plinths may often be the safest option in real-space, but the model needed something more playful. In the end I opted for a mixture of patterned, plain white and veneer-clad plinths. Another thing that was clear to us from the beginning was that there needed to be some juggling with the scale of the objects themselves .. so that the smaller objects could retain enough presence in competition with the larger. This is a feature of traditional dollshouses .. whether intentional or not. I chanced upon the idea of making ‘positional rakes’ similar to those used by a croupier, because participants needed to be given more ‘reach’ .. we couldn’t do away with the three main walls because the ‘paintings’ would need them, so the model could only be comfortably accessed from one end.

'The Patron's House' David Neat, Contemporary Living at Christie's, April 2017

'The Patron's House' David Neat, Contemporary Living at Christie's, April 2017

I had the chance to take photos of the individual model pieces while they were still in my studio, so I’m presenting them here followed by the photos of the real-life pieces I’d been using as reference. I often only had one publicity photo to work from plus outline dimensions, though The New Craftsmen provided a thorough series including details and good ‘white balance’, which helped a lot when trying to assess true colours or identifying materials. Nevertheless with many of the objects I had to settle for a reasonable ‘overall suggestion’ or sometimes even a ‘playful variation’ on the essential look. This was just as well because it was perhaps inevitable that the galleries had to make some mid-term changes to the exhibits, meaning that what arrived was a different version of what I’d been working on. For each object I’ve also included some notes on the materials and the processes I used, some of which I developed specially for this work.

Conrad Hicks

Conrad Hicks 'Implement Table' and 'Copper Chaise', Southern Guild, models by David Neat

Conrad Hicks 'Implement Table', Southern Guild, model by David Neat

South African Conrad Hicks works principally with forged metals, in these cases copper and iron. I had to use real copper sheet to achieve the look but the verdigris is just an acrylic paint job. After experimenting with a few different scaled thicknesses of copper before it would behave, I finally spraymounted two of the thinnest together to combine the right strength with easy bending. I didn’t have to beat it! .. the texture was easily done with an embossing tool. Deciding what to use for the iron frameworks was difficult at first, but in the end cutting out shapes in 3mm black Palight ( foamed Pvc ) proved the best solution. Below are the photos I was referencing for Conrad Hicks Copper Chaise and Implement Table, both forged copper and iron, courtesy of Southern Guild.

Conrad Hicks 'Copper Chaise', Southern Guild

Conrad Hicks 'Implement Table', Southern Guild

I wanted the plinth decoration throughout the range of objects to be as noticeable but also as subtle as possible .. and I wanted it to last, and not get dirty from handling. I wanted colour and pattern to ’emerge’ from the surface .. so neither direct painting nor pasting paper prints would do! I also wanted the pattern to fade out smoothly at the top, otherwise it would clash too much with the objects. In the end I found that inkjet printing 100micron clear transparency film with found pattern images and gluing inked side down to the plinth Pvc with strong spraymount ( Photomount or Craftmount ) did a perfect job! To be safe I let the printed sheets dry for a day before using (the ink takes much longer to dry on acetate). I also needed to prepare special strip portions of the pattern images first, using the Graduated Filter in Paint Shop Pro to fade each strip at the top. Once applied and trimmed, I ‘silked’ the surface of the film to take away the gloss with fine abrasive cloth.

Sebastian Cox

Sebastian Cox 'Scorched Shake Sideboard', model by David Neat

Sebastian Cox 'Scorched Table', model by David Neat

The British furniture maker Sebastian Cox, represented by The New Craftsman, uses traditional woods .. specialising in coppiced timber and self-managed woodland .. but often subjects them to a very controlled surface scorching resulting in a deep black. For both his sideboard and large table I found again that black Palight worked best of all because I could vary the surface effects from a slight-sheen sanding for the sideboard to a deeper matte graining on the table. For the front doors of the sideboard, which in reality are composed of cleft ‘shakes’ .. a form of shingle traditional to Japan .. I had to texturise thin strips of 1mm white Palight, apply them, then paint them with matte black Humbrol enamel. I dry-brushed with a slightly lighter acrylic to further emphasize the texture. I felt that the table needed a simpler, veneered plinth .. in this case oak sealed with water-based ‘satin’ varnish. Below is the real-life Scorched Shake Sideboard, but since the table was a new work there is no proper photo as yet ( courtesy The New Craftsmen and Gareth Hacker Photography ).

Sebastian Cox 'Scorched Shake Sideboard', courtesy The New Craftsmen and Gareth Hacker Photography

Dokter and Misses

Dokter and Misses 'Kassena Isibheque', model by David Neat

Dokter and Misses are not a married couple in spite of what the name might imply, but a multi-disciplinary Johannesburg design company of more than two. One of their special ‘Editions’ .. as different from their ‘Products’ .. is their ‘Kassena’ collection, a unique looking range of robust wooden cabinets which are all hand-painted, inspired by the painted adobe structures of the Kassena people from the border region of Ghana. These cabinets contain drawers which are almost hidden apart from tell-tale hand slots .. because my time was limited I had to sacrifice this feature. For the same reason and also because of the minuteness of the scale I had to simplify the geometric patterning (which does actually represent texts in an indigenous writing system) and resort to Letraset to create an effect. Below is the original, hand-painted solid beech wood Kassena Isibheqe, courtesy of Southern Guild.

Dokter and Misses 'Kassena Isibheqe', Southern Guild

Bristol Weaving Mill

Bristol Weaving Mill, Rag Rugs ('Blue Ombre' and 'Yellow & grey'), models by David Neat

Also represented here by The New Craftsmen, BWM had two rag rugs in the show made by Juliet Bailey, one of the directors. In the model I mounted these either side of a freestanding plinthed wall piece. For the first time I felt I was using my usual recommendation to use painted sandpaper for carpets to good effect! I painted a very coarse sandpaper white first then detailed the colours in matte acrylic. Below is one of the two originals, the Yellow & grey courtesy of The New Craftsmen.

Bristol Weaving Mill, rag rug 'Yellow & grey', The New Craftsmen

Mock Mock

Mock Mock (Pieter Henning) 'Stone Tables', model by David Neat

Pieter Henning’s design label Mock Mock produces, amongst other things, simple combinations of copper and stone of which these ‘tables’ are an example. Henning comes from the Klein Karoo valley in South Africa. I didn’t stand a hope of bending and soldering flat metal strips at this scale so I cut the slender shapes from thin styrene sheet, combining with discs of thicker Pvc.

Detail of Pieter Henning's 'Stone Tables' for Mock Mock, models by David Neat

To suggest the coloured stone or marble patterns I started with a generalised base colour, then stippled spots of lighter acrylic using a piece of reticulated foam. Tissuing this before the paint was properly dry created a more natural and varied effect. The copper is simulated with Humbrol metallic enamel. Below are the items Southern Guild originally intended to send .. the ones which arrived were significantly different, not as colourful though of the same type. In a sense this didn’t matter .. it became part of the model’s separate and playful existence.

Pieter Henning 'Stone Tables' for Mock Mock, Southern Guild

Gareth Neal and Kevin Gauld

Gareth Neal & Kevin Gauld 'Brodgar Bench', model by David Neat

The ‘Brodgar Bench’ featured on the left above was designed by London-based designer Gareth Neal and made by Orkney chair maker Kevin Gauld. The model needed to be mainly wood, nothing else would have been right .. in the end I used a combination of obeche, limewood and bamboo for strength. For the woven straw back I resisted trying any woven fabric, fearing a fibrous mess .. so ended up engraving the weave pattern in 1mm Palight (to the right is a day-bed from Louisa Loakes & William Waterhouse which will feature separately in Part 2). Below, the original Brodgar Bench, oak with woven straw back. Courtesy of The New Craftsmen

Gareth Neal and Kevin Gauld 'The Brodgar Bench', The New Craftsmen

Jesse Ede

Jesse Ede 'Lunar Bench', model by David Neat

Lastly for this part, another very different form of bench from the South African Jesse Ede. Most of the original was cast in recycled aluminium, making use of the rough, pitted texture .. so Humbrol ‘silver’ enamel with a little sand mixed in simulated this perfectly. The distinctive slate shard was easiest to model in polymer clay then paint using my ‘open foam print’ technique. The photo of the Lunar Bench in recycled aluminium and Malmesbury slate is courtesy of Southern Guild. The photos illustrate how one needs to be wary of foreshortening when judging photos .. my proportions are fairly accurate!

Jesse Ede 'Lunar Bench', Southern Guild

 



 

 

 

Making a panelled door in stencil card

Recently I was asked by a friend to cover for her on the ‘Foundation in Art & Design Diploma’ course at Central Saint Martins. The day was intended to deal with aspects of model-making relevant to a project the students are currently working on. Each is designing an enclosed space with particular emphasis on the doorway leading into it, so we took the opportunity to focus on doors and the different methods of simulating surfaces.There was no budget available for materials so I had to devise a short practical using whatever small leftovers I could spare. The most promising idea seemed to be working with stencil card since I had a lot of small pieces, and stencil card was available at the CSM college shop if the students wished to take it further.

making a panelled door in stencil card

So I spent a bit of time working out the easiest way to make the traditional panelled door above. I’ve already looked at layering stencil card to create the wall panelling effect below and I also discovered some time ago that stencil card could be scraped with sandpaper leaving a fairly convincing ‘woodgrain’ effect, but I hadn’t combined them much. Also, the panelling below was made by carefully marking out and cutting the layers separately, then just as carefully aligning them while gluing. This is quite demanding! .. I wanted to make it more achievable.

using stencil card for wall panelling and windows

The improved method involves four layers (but as yet only dealing with one side) and the only ‘graining’ done is on the top layer and on the bottom layer where the ‘panels’ are seen. Everything is led by the ‘second layer down’ .. the one shown first in the line-up below, on the left. This is the one which needs to be carefully measured, marked out and cut. These doors are 1:25 scale and I’ve rounded off the UK average for a traditional interior door as .. 198cm high by 76cm wide. If you want to be either very specific or if you’re working in feet and inches, it’s properly 6′ 6″ by 2′ 6″! What happens within that outline is more a matter of taste .. there are no similar ‘standards’ for the size or arrangement of the panels. I’ve cut the first piece of card according to what looks right, but also I’ve observed with 4-panel doors that the top pair are usually longer than the bottom and there’s most often a broader strip across the base of the door for strength. The long thin panel in the middle is not meant as a letter box but it could house one, and the handle or doorknob would be positioned roughly halfway up the door which makes it on average a little less than 1 metre up.

stages in making a panelled door in stencil card

The drawing below should print out on A4 at exactly 1:25 scale and if you’re using this design as a template only the first one needs to be traced or pasted, as I’ve said .. the others are just there to illustrate each stage of layering. It goes like this .. after the first is cut out it should be stuck down onto another scrap of stencil card leaving a small margin around it. Spraymount works well, as long as you don’t intend to treat afterwards with a spirit-based medium because this will dissolve the glue .. otherwise superglue applied with care (very thin lines or dots) works perfectly. Pva wood-glue will grip but not bond very well with the stencil card surface. Trim around the outline of the door using the top stencil layer as a guide then judging by eye cut out all the panel areas a little inside the top-piece outline all around making a little ‘step’ .. as illustrated by stages 2-3 above and below. It may take some practise to get an even strip but it’s too slight to measure/mark. I’ve used the smallest division on the 1:25 scale ruler as a visual guide.

stages of making door using stencil card

This piece is then stuck onto another piece of stencil card and the outer edge trimmed again as before .. before doing this the stencil card which comes underneath needs to be ‘grained’ first because this will show. For these examples I’ve used a small piece of 120 grit sandpaper to grain, pressing firmly down and straight along, using the edge of a metal ruler as a guide. Once all three stencil card layers are stuck together and the door outline trimmed around once more (stage 4 in the line-up above), the fourth and final layer comes on top. This one is applied differently though, in separate pieces. It has to be because the grain of each strip must follow its longest edge .. essential for a convincing look! The task becomes a bit like marquetry in wood, but much easier because the stencil card is easier to cut. I grained a much larger piece of stencil card first and cut the strips from it, and I made these a little narrower to form a final ‘step’ around the panel areas.

colouring stencil card door with ProMarkers

There’s almost no end to what one can use to stain or paint stencil card because, in spite of the linseed oil waterproofing, it will accept both water-based, oil or spirit-based media. I’ve detailed a number of these already in my post February 2015 The art of alternative staining where I’m working with wood, but all will work well on stencil card. In fact many will work better because although a fine-grained wood is often the best option for a good ‘wood’ look when it stains well, it can also be difficult to eliminate the scattering of light specks where the polish or stain has failed to penetrate. Generally stencil card accepts stain a lot better and more evenly.

For the two samples above I used Letraset ProMarkers. The alcohol ink in these covers well and dries quickly, though it stains so well that the lighter scratches tend to disappear. These are ideal if you want something subtle. The ProMarker ink itself dries matte but there is a very slight sheen from the stencil card.

staining stencil card with Marabu GlasArt

If you’d like more shine or even brighter colours another option is using Marabu Glasart glass paints above, or ‘vitrail’ as they’re often labelled. These are spirit-based and, in the case of the Marabu, can be diluted or cleaned up with white spirit. One has the choice of either a silky or a glossy finish dependent on how much is applied. Here for example I brushed the vitrail on thinly and also went over with tissue and cotton bud to remove the excess collected in the raised edges .. if I’d just left it the effect would have been more glossy. Vitrail doesn’t work well as successive coats, because like shellac a further coat just starts to dissolve the one underneath and the results could be patchy.

colouring stencil card with shoe polishes and wood-stains

As shown above, if you’re intending a worn or ‘distressed’ effect I would recommend either a liquid shoe polish (which are almost always water-based) or a water-based wood varnish. These will tend to sit more on the surface rather than staining, and with each of these samples I started to rub or gently scrape after only a few minutes, before fully dry .. achieving a properly ‘chipped’ look fairly easily. These are, from left to right, Wickes ‘Quick-dry Woodstain’ mahogany; Cherry Blossom brown shoe polish, Kiwi ‘Wax Rich’ black shoe polish. Stencil card will warp a little with water-based media but not as much as other cardboards and, once dry, it is easier to bend carefully back into shape.

Conventional wood-stains also worked well .. both spirit and water-based. The middle one has a light coat of Colron ‘Georgian Oak’ and to the right I have used a water-based ‘Dark Oak’ wood-stain from Flints in London. The spirit-based stain has remained fairly matte whereas the water-based dried to a slight sheen. Spirit-based stains will also infiltrate quickly to the other side, even when more than one layer .. worth bearing in mind if this will be seen.

colouring stencil card with shoe polishes and wood-stains

Lastly, for the pale sample to the left I tried Osmo Dekowachs ‘Transparent White’. This is a specialist wax-based paint I was using in Germany which I still have some of, though these paints are also available in the UK. Like Humbrol enamels I’ve found that these paints will fix on almost anything. The first coat of Dekowachs is always matte and one has to build up a shine with further coats.

Poor substitute stencil card

For those of you interested in what I do with stencil card as I’ve described in my article Working with stencil card under ‘constructing’ in the Materials section, I have to warn you that there’s an inferior substitute appearing in some of the UK sources I’ve listed. The proper, traditional material I’ve always relied on is an attractive honey/ochre colour, is 375 microns thick and smells very noticeably of linseed oil. I first noticed the ‘poor’ stuff at 4D modelshop who, I’m assuming, had been forced to accept what started to come from their usual supplier, but now I’ve seen the same change in University of the Arts college shops which suggests that this may become more widespread. The inferior type is a darker, dullish brown, seems a little thicker; and has a very different and far less agreeable smell. More importantly .. it is a little tougher to cut, certainly doesn’t cut as sharply, frays at the edges much more easily, and the method I recommend for ‘graining’ the surface with sandpaper just doesn’t work! The surface merely disintegrates, becoming very ‘wooly’ and loses further definition when stained or painted. This stuff may still offer some advantages over more regular thin white card, for its strength and for basic cutting of delicate forms .. but in other respects and for my purposes it’s pretty useless!

comparison of different stencil card types

My advice is to speak directly to the supplier if you are buying stencil card online .. check for sure that it is the standard ‘honey’ colour and not the dull brown, and that it is 375 microns thick (because there’s also a thinner 250 micron version sometimes sold in its place). The other day I bought the proper stuff from Flints in London, and I’m fairly sure that A.S.Handover and Wrights of Lymm will still be supplying it. These three also offer by far the best prices!

Coating styrofoam with polyurethane resin

These are the latest forms I’ve been making for my .. not-quite-working-title .. Ridiculously Organic Construction Toy. For this I’ve been creating simulations of eroded rock and driftwood cast in resin, twisted Pvc branches covered in fake moss and lichen, corals, leaf clusters and strands of seaweed made from latex etc. But I also wanted to include some play elements which are more obviously scaled down, such as these brickwork ruin pieces. The best way of picturing the whole idea is to think of aquarium or reptile tank accessories and then imagine getting a large collection of these instead of a box of Lego. I’m still working on the question of how exactly the ‘construction’ is achieved .. i.e. how such components will be fixed together when playing .. but as part of the system I’m working on an artificial ‘mud’ which I’m hoping will solve part of it.

ruin fragments in resin-coated styrofoam

The forms above were cut/carved in regular blue styrofoam, textured using a heavy-duty wire brush and then coated in polyurethane resin. There’s a bit more to the ‘painting’ process .. something new I haven’t tried before .. but I’ll come to that. If properly done the method of resin coating makes the forms unbelievably strong! .. perhaps not enough to survive little children, but certainly any adult wear-and-tear.

Making a brickwork arch in styrofoam

These two photos illustrate other forms intended for the collection and the process of making them. I’ve described this method of form-making in more detail in Shaping styrofoam. The arch piece above started with a Pvc template, which I used to help sand a block shape. I found I had to make a separate drawing template (the one at the bottom) just in order to inscribe the brick pattern onto the styrofoam shape. Then I used the special diamond needle files pictured to scratch out the brickwork divisions at the right thickness. I wanted these pieces to be 1:12, i.e. usual dollshouse scale, but I’ll eventually use a mixture of scales.

Making a brickwork niche in styrofoam

To make the ruined ‘niche’ shapes above I also used the method I described in Shaping styrofoam of using a curved sander to create the concaves. I roughed out very deep channels for the mortar lines, because these will become partially filled with coloured resin .. and this is what gives the pieces unusual strength. I found it was better to make all the channels before attacking with the wire brush, because I made the pitted texture mainly by hitting or pressing with the brush. This peppers the foam with deep holes and it may fragment a bit too much if the channels are made afterwards.

diamond needle files

Here is a close-up of the type of file I’ve found to work best for detailing foam. These have a ‘diamond coated’ surface which has more of an effect on relatively soft materials than the other, cheaper, form of needle file which is just ‘toothed’, grooved metal.

wire brushes useful for texturing rigid foam

I usually use the smaller brushes pictured above when working with the more delicate polyurethane foam in Kapa-line foamboard, but styrofoam has a tougher surface .. the heavier wire brush has more effect. Importantly, the action in this case is not a brushing or sweeping one, it’s more hitting downwards and rocking around .. I call it ‘scumbling’.

styrofoam 'ruin' fragments

Now to get to the main point of this article! Of the polyurethane resins I most often use (Sika’s Biresin G26 and Tomps’ Fast Cast) I know that both can be used in the following way, but Tomps Fast Cast is best because it’s a little thinner, powder pigment mixes better into it, and according to Tomps it is designed to cure properly in very small amounts or in very thin layers. This is not the case with all polyurethane resins. I’m basically making a very quick-setting paint with it, and because it’s quick-setting it has to be done a little at a time. To dose both resin parts I use disposable plastic pipettes (which are available from a few places online) and usually work with not more than 2ml of each part at a time. I can normally manage to use up to 4ml before it thickens too much. Because there’s usually no time spare to clean the palette surface before it sets I use a ceramic tile which can be scraped clean afterwards. There’s always just enough time to clean the brush though, and this can be quickly done with acetone.

Coating styrofoam with polyurethane resin and pigment

Here I’ve dosed 1ml of each resin part together on the tile, added a small amount of powder pigment, mixed the whole together with a synthetic-hair paintbrush and used the same brush to paint the foam. Synthetic is best because the hairs will be rigid enough to push the pigmented resin into deep pattern, but full and fine enough to hold a lot of the paint. Powder pigment is the best form of colour to use .. strong colour, inexpensive, available .. and I usually find that it mixes better into resin than it does with water!

The polyurethane resin has no effect on styrofoam (unlike polyester resin), it will cure hard and ‘fused’ to the surface, and it’s done .. that is, it’s touch-hard and ready for further work .. in about 15 minutes! Whereas regular paint such as acrylic will infiltrate more and contract as it dries, polyurethane resin does less of both so there will be a little ‘smoothing over’ of fine surface detail. It will also be a gloss finish! .. which I don’t like, would never choose, and at the moment I’m experimenting with the different  ways of dealing with this. There is no matting additive for polyurethane resin, and regardless of which pigment or filler is mixed with it, the top surface exposed to the air will always be glossy. Obviously painting over with another matte paint, such as a good acrylic, is an option .. but polyurethane needs a lot of preparation if the paint coat is to resist a lot of handling and this is made difficult by such a patterned/textured surface.

One possible solution is to use my own version of cold powder coating. If you google ‘powder coating’ you will find that this refers to an industrial painting process in which fine thermoplastic powder is melted onto metal to create a durable surface. It’s very like the enamelling that you might have done at school, with coloured glass powder on a copper plate, melted in a small oven. My version does not require heat, and it’s perhaps more related to the model-making practice of scattering granules into glue to create a surface .. but it does share some of the surprising durability of these other methods!

crushed brick

Below is a close-up of the styrofoam ‘ruin’ forms after coating. I first gave the bare styrofoam an undercoating of resin mixed with black pigment, and then a second coat without any pigment, covering a small area at a time. While each portion was still wet I sprinkled a mix of finely crushed brick and sand onto the resin. I’m fortunate in that, living close to the Thames beach, I can pick up fragments of any colour of brick, illustrated above. Since these have already been broken down by the elements they are much easier to crush to a powder using mortar and pestle.

detail of brickwork surface done with 'powder coating' method

While working I could see that the particles were readily sinking into the thin coating of resin, and when the excess is shaken off after a few minutes the powdery top layer still adheres strongly. Polyurethane resin is a strong adhesive, especially if the dust or particles are porous and jagged. Having tested the strength of the surface once the resin cured I have little doubt that it is permanent. I still have to do some paint finishing on these pieces, emphasizing contrasts and colours and giving more ‘speckle’, but I have no worries about regular acrylic paint attaching itself on top. The greatest bonus in this particular case is that these pieces have a lot of the look and feel of real brick .. because that’s what it is!

 

Using plaster as a filler in polyurethane resin

I’ve been asked this question a number of times now .. whether regular plaster can be used as a filler for resin, in place of the other ‘white’ powders more commonly used such as talc, chalk dust, marble dust etc. Don’t forget that these are all versions of calcium carbonate and are chemically inert, whereas plaster is calcium sulphate and certainly not as ‘inert’ since it reacts so strongly with water. I hadn’t ever considered it as a filler, and hadn’t heard of any cases of it being used in regular practice. My advice up to now had therefore been to avoid it, because I assumed that it could affect the curing of resins. Plaster is hygroscopic meaning that it will readily absorb moisture from the atmosphere however well it might be stored. Powder pigments are the same, and I have found that the slight moisture in them will cause polyurethane to foam and expand a little even when just a little pigment .. i.e. up to 10% by weight of resin .. is added. So I always assumed that adding a more substantial amount of plaster would cause bigger problems .. not only affecting cure but probably also thickening the resin too much to pour properly. Yesterday I finally found the time to do some tests using a couple of regular plasters with polyurethane resin and discovered that although there are some adverse effects these could also be turned into benefits.

Expansion of polyurethane resin when filled with casting plaster

For the first test above I made a control mix of Tomps Fast Cast polyurethane resin without any filler .. 15g of each part, so 30g total. The mix set touch-hard in just a few minutes as normal, becoming a pale ivory solid (the cup on the left). I then did the same but added an equal weight (30g) of Crystacal R which is a fine, hard, ‘alpha’ casting plaster. As per usual with polyurethane resin, the whole amount of filler has to be mixed thoroughly with Part A before adding the hardener Part B.

Whereas mixing is usually very smooth using conventional fillers such as Fillite, the plaster/resin needed a lot more stirring before the lumps disappeared. But after some effort the two combined making a smooth but thick liquid .. like treacle. As usual though, this thins down quite a bit once Part B is added, and the resultant mix was still very pourable. Far from the reaction being slowed down by the plaster I found that the cup started to get warm very quickly, and then the liquid started to expand. Once it had set touch-hard it had practically doubled its volume, as shown by the initial mark I’d made on the cup. The mass was solid, hard and ‘dry’ within 30mins .. there was no under-curing, failure to mix or greasiness on the surface .. all the indications of a good cure!

comparison of volume of 30g unfilled resin with 30g plus plaster filler

What was completely unexpected was the change in tone .. from the normal clean, pale ivory to something slightly darker, dirtier as shown here .. and I can’t really explain that yet! The test piece detached cleanly from the cup and the surface was smooth as shown below. The only indication of foaming was minute but noticeable pocking of the surface towards the top, none at the bottom.

I measured the volume increase compared to the control pour, both before and after foaming. The control pour measured 30ml in volume once solid, roughly consistent with the SG (‘specific gravity’ or weight per ml) of the combined resin parts given by the manufacturer as 1.1g. The volume of the same amount of resin with 30g of Crystacal R added .. before expansion .. was just 40ml. This is also consistent with the way plaster behaves in water, absorbing much of the liquid volume. The volume of the expanded mass once set touch-hard was 70ml.

effects of foaming visible on cast surface

I expected a roughly similar result when I repeated the test using the same proportions with pottery plaster in place of Crystacal R  .. but the result was more dramatic! Pottery plaster is a coarser, softer-setting ‘beta’ plaster, called ‘pottery’ plaster because it’s designed for making the absorbent plaster moulds ideal for slip casting. In the first place whereas the 30g Crystacal had combined with the 15g Part A resin eventually as a smooth liquid, the same amount of pottery plaster became a thixotropic paste rather like car body filler. Addition of Part B thinned it considerably but it was still a significantly thicker liquid than that obtained using the Crystacal.

expansion of polyurethane resin when filled with 'pottery' plaster

But more importantly, foaming was more ‘aggressive’ producing larger bubbles and until it set hard the mixture expanded to almost three times its original volume. As before though the mass became solid and hard within 30mins with no tackiness or other evidence of failing to cure.

larger-scale foaming on surface using 'pottery' plaster

However, as shown below there was more noticeable damage to the cast surface in the topmost area because the bubbles here had become much larger. As with the Crystacal the volume of 30g resin combined with 30g pottery plaster prior to reaction was 40ml, but this expanded to 115ml before setting firm.

larger-scale foaming visible on cast surface

I made a sectional cut through the upper parts of both test pieces and sanded the surface .. the fine casting plaster to the left and the pottery plaster to the right below.

cut sections showing foam structure

I can only account for some of this marked difference in behaviour. The fact that the pottery plaster appeared to thicken the mix more is predictable .. it is because of the shape of the particles. Commercial fillers such as Fillite are composed of minute microspheres which roll over each other meaning that quite a lot can be added to a liquid without affecting its flow too much. The particles of pottery plaster must be jagged, causing them to clump together whereas those of the Crystacal must be finer and smoother. As for the stronger foaming reaction and increased expansion .. the pottery plaster was older than the Crystacal and may have acquired more moisture; it may also contain an additive; or it could have something to do with the particle size. I’m not entirely sure!

I imagined though that whereas plaster would never be a sensible option for flawless casting, these results could have some uses. At the moment I’m making cast versions of pieces of driftwood to use as components in a sculptural project. So far I’ve been hollow-casting these in polyurethane resin, but using Fillite as a thickener. I’ve described this casting process in my article Making hollow casts in open or closed moulds in the ‘Methods’ section under ‘Mouldmaking and casting’. One difficulty with this technique is getting a thick enough build-up, especially on vertical surfaces, when using polyurethane resin because there is no way of making it truly thixotropic. I tried the pottery plaster/resin mix for coating these moulds below, with a little black pigment added. I found that because of the swelling it was much easier and quicker to build up a thick shell, even on the vertical parts.

making a hollow cast in polyurethane resin

I also found, as I’d observed from the cup tests, that since the foaming is largely directed upwards there was no damage or loss of detail on the cast surfaces. The intricate patterns of weathered wood have reproduced perfectly here!

hollow casts using filled polyurethane resin

 

 

The art of alternative staining

This was meant to be just another short ‘hidden treasures of the pound-shop’ piece recommending the value of cheap liquid polishes such as these below as alternatives to more expensive wood stains. I’ve used similar bottled shoe polishes many times in the past, particularly for staining model floorboards .. with very good results!

Poundland liquid shoe polish

But these ones currently in 99p Store are, as you can see below, unusually weak in terms of colour. I’ve made these tests on pieces of 0.8mm sheet obeche wood, which normally accepts stain very well. Each of the sample pieces featured in this post was made with a fixed procedure! Firstly I ruled three faint pencil lines and applied the first coat up to the top pencil line, leaving a little of the wood bare above. I then waited a minimum of 2 hours before applying the second coat up to the line below and then another 2 hours before applying the third. I chose 2 hours in between because this was the time it took for the pieces of wood to return to almost complete flatness after warping .. so I figured these were sufficiently dry for the next coat. As you may know, warping doesn’t occur with oil or spirit-based media, and with spirits the ‘drying’ is a lot quicker .. but I gave these the same intervals anyway.

Poundland liquid shoe polish samples

The polite word for these is ‘subtle’ .. the ‘Neutral’ had so little visible effect on the wood, even after three coats, that I didn’t even notice that I’d photographed the piece upside down! The brown and black did impart some even colouring as you can see, but even after three coats and rubbing afterwards there was only slightly more ‘sheen’ than the obeche wood has on its own.

But there are much better ones! The lighter brown sample on the left below is brown liquid polish from Tiger, the one in the middle is brown Cherry Blossom Readiwax    brand found in Poundland and the last is Kiwi Wax Rich Colour Shine also from Poundland but a while ago. I’ve overdone the photo exposure a little .. the colours are richer and deeper in reality. All of these gave a visible, regular sheen to the wood surface on the second coat, and more pronounced on the third.

liquid shoe polish samples on wood

Here are just two more, but also showing how best to apply the liquid polish. The sample to the left is the brown Kiwi Colour Shine shown in the photo, also found in Poundland, and next to it is one made with Clarks brown polishing cream, which is thin enough to brush on easily and infiltrate the fibres. The Kiwi polish gave a good sheen after three coats but the polishing cream remained matt. If you intend to cover large areas you could use the sponge applicator attached, but for these small ones it was easier to press out a small amount of polish on a tile and use a rigid synthetic brush.

Applying liquid shoe polish as a stain

All of the polish types I’ve featured so far are ‘water-carried’ including the polishing cream .. suspensions of pigment and wax in water. So one has to deal with the fact that the water will make thin wood warp! It can look rather alarming .. especially if as here the wood grain is perpendicular to the length of the strip. But as the piece slowly dries it returns to almost complete flatness again. As I’ve said, if using 0.8mm obeche wood this will take at least 2 hours .. but it will differ according to wood thickness and type.

thin sheet obeche warping with water-based polish

Although it might be an annoying way to work, I would recommend if you want to treat wood with anything water-based (including water-based commercial wood stains) that the pieces are treated like this i.e. stained and left to dry before sticking down. It may be logical to assume, when making a floorboard floor for example, that sticking all the boards securely on a base first will prevent the whole thing from warping when painted. It doesn’t .. in fact it can make it worse! I think what happens is that if something absorbent like cardboard is used as the base, when the wood on top is painted some of the moisture reaches the cardboard so it will also warp .. this is clear. But as both dry out the moisture which has reached the cardboard is trapped so that whereas the wood layer will dry the cardboard will take longer. The drying wood will therefore ‘set’ in this position. When this happens it is impossible to get the ‘composite’ flat again.

It can be a bit dangerous if one gets hooked on the satisfaction of making illustrative samples .. one looks around for more things to test! Samples don’t have to have any other meaning, and one isn’t going to be judged on their aesthetic value. Breaking free of both the conceptual and the aesthetic actually does have positive advantages sometimes.. it opens the door wide for serendipity! Otherwise I wouldn’t have thought of trying two other media I just happened to have around at the time .. GlasArt transparent glass paints from Marabu and Letraset ProMarkers. As it happened both worked far better than I expected, with the big advantage that neither of them cause warping because they’re spirit-based. The other significant advantage is the cost of them. If one only wants to stain a relatively small area it’s quite an expense to buy commercial spirit-based wood stain, or a combination stain/varnish. The smallest tins or bottles available are generally somewhere over £6.00. The smaller 15ml jars of Marabu GlasArt can be found for between £2.00 – £2.60 and Letraset ProMarkers are on average £2.00 each.

Marabu GlasArt paint as wood stain

The GlasArt paints work like a dream on wood! They can either be applied straight from the jar, as I’ve done with the sample to the far left above, or thinned with white spirit as I have with the other two. I used Bartoline Low Odour White Spirit and mixed roughly equal amounts of spirit and paint together on a tile. As before, the best brush to use is a flat one, with soft but rigid synthetic hairs. The first coat penetrates readily but dries relatively matt; the second has more noticeable sheen, and the third gives a regular satin finish. Whether thinned or used straight, the GlasArt paint penetrated the wood fibres better than I expected. For an even stronger shine I would recommend applying some neutral Kiwi solid shoe polish such as the one shown later. This has to be thinly brushed or rubbed in, left for about half an hour, then buffed with either a clean shoe brush or soft rag. I would recommend using a polish like this every time for scale model work, rather than using any kind of gloss varnish. Varnish is too ‘full on’ for miniature work, and it will emphasis every little imperfection. Often the sheen that the wood already receives is enough to suggest a polished look, but if one has to have more, polish can be far better controlled. It means for example that a floorboard floor stays more matt where it is difficult to buff i.e. along wall edges or in corners, which makes more realistic sense!

Marabu GlasArt used as varnish on wood

Letraset’s ProMarkers come in a wide range of colours .. 148 in total. Below I’ve used a few I had which were suitable as wood colours, but there are many more. In addition they can be easily ‘mixed’ .. that is, overlaid .. so the colour range is infinite! The ink is alcohol-based and it penetrates the wood fibres very well. But it is also ‘self-sealing’ .. there must be a fixative in addition to the alcohol, though there is no info on what this is .. so transparent layers can be built up and colours deepened. Here I’ve used, from left to right; ‘Ice Grey 1’, ‘Sandstone’, ‘Spice’, ‘Walnut’ and ‘Warm Grey 5’. Although the ink is thin, a build-up of layers will produce a sheen, though not as much as the GlasArt paint or the better polishes. Another advantage for small-scale work is that the ProMarkers come with both a broad and a fine felt nib. Because it penetrates so well I expected it to be difficult to draw a hard edge on the wood, at least for the first coat, but as you can see from the top edges it didn’t ‘bleed’ as much as regular wood stains.

Letraset ProMarkers used as wood stains

This could make it easier to ‘fake’ a more complicated parquet flooring pattern, just by using different tones or hues of marker. It can be fairly tightly controlled even on balsa wood, which is one of the most absorbent woods. Below I’ve compared the same colours on balsa, to the right, with obeche to the left. Balsa generally stains more evenly than obeche, especially when layers are built up, but obeche will give a richer and deeper colour.

Staining wood with Letraset ProMarkers. Difference between obeche and balsa

One last option .. let’s say, if you don’t want to get anything special at all for staining wood .. is just to use whatever transparent paints you’ve got such as watercolours. If you do use watercolours I would recommend painting before gluing down, as before. Don’t use either acrylics or gouache because these will not be sufficiently transparent .. they will obscure the natural grain of the wood, and the effect will be rather lifeless and artificial.

In place of watercolour though, I prefer to use regular colour pencils or pastels ‘dissolved’ using white spirit. This avoids the problem of warping, but I’ve also found that the colours are richer using spirit, and it means that so many more things can be turned into paints or stains. These small floor samples were made by firstly shading some pencil colour on the bare wood, then dissolving it with low odour white spirit and a synthetic brush. The dry pencil pigment dissolves readily and can be worked over and into the wood, but the ‘paint’ produced remains workable for much longer than watercolour or acrylic. It is basically a straight ‘watercolour’ technique .. just not using water .. and with the added control of adding the colour, not solely with a brush but also with the pencil-point .. a combination of painting and drawing. I’ve preferred to keep these samples subtle to show the nuances achievable, but one can go much richer and darker with the colours.

Staining wood by rubbing with coloured pencils and dissolving pigment with white spirit

I’ve used Karismacolor pencils here because these were my favourite and I still have them, but sadly Berol discontinued them long ago. Others who use colour pencils in their work say that Prismacolor or Polychromos are comparable .. rich colours, soft but not chalky-fragile! These are all oil-based pencils, which definitely work better for this technique, though I have found that any kind of colour pencil will work to some extent.

Old oak floorboard model sample

For the sample floorboard piece above, and below, I wanted to simulate the distinctive markings of old oak, but using obeche. I cut the planks and sanded the edges a little first, then ‘distressed’ them variously using a heavy-duty wire brush .. either pressing and pulling for deep scratches or just pressing and rocking for pockmarks. I then glued them in place, inscribing the floorboard ends with a sharp tool afterwards. I used the pencils to shade or cross-hatch on the wood in various browns, but defining some differences between the floorboards. When dissolving the shading with white spirit I made sure that most of the colour collected in the scratches .. conventional wood stain would most likely colour too uniformly, not differentiating enough. Much more variation could be achieved than I’ve shown here, by shading parts with pencil again and fixing with very minimal spirit.

Wood staining sample including old oak floorboard effect and solid shoe polish rub

But the pencil/white spirit technique doesn’t create much shine, so after I’d given the sample a few hours to dry I applied a thin coat of the solid shoe polish shown .. a ‘Dark Tan’ to give it a bit more warmth. One needs to wait for it to ‘set’ before polishing .. between 30-50mins. As one final test I tried the polish on an untreated piece of obeche and got a deep, satisfying shine .. though adding further layers of this polish did not deepen the colour.

Staining and polishing wood with standard shoe polish

 

Handy containers for small amounts of paint

One of my favourite paints is Rosco ‘Super Saturated’ scenic paint .. I like it because it has a more liquid consistency than most other acrylics, thins and mixes easily, adheres better than most to non-absorbent surfaces, covers incredibly well and dries almost completely matt! However, a major disadvantage is that it is only available in 1litre tubs .. really rather prohibitive in cost if you’re not a scenic painter and if you want a full range of colours! Added to that, the paint doesn’t keep very well once opened .. after about a year on average some of the colours start to smell, curdle or later still develop a thick skin of mould (but see postscript with solutions below). A couple of years ago I seriously splashed out on a number of 1litre tubs, partly because I intended to provide this paint to be used on my courses. Rosco has put together a sample box with small amounts of each colour .. costing around £50 if you can get hold of one .. but these sample pots don’t hold very much and once the seal is broken the lids aren’t quite tight enough to keep the paint inside from drying out.

Rosco SuperSaturated range

I needed to find better and more secure containers to transport portioned amounts. I’ve tried the smallest available food containers and for a while these worked quite well, but even these are a little bit bulky to transport in large numbers, if one wants to provide an interesting range. In any case none that I tried were truly ‘watertight’ so I had to bind them for transit with electrical tape. It also meant that the paint could only be properly dispensed from them with a spoon. What it did seem to solve fairly well was the problem of the paint ‘going off’ because I could fill a number of these to the top and thereby reduce the air contact. Nevertheless, I just didn’t like working with them .. too messy!

using food containers for paint

Another of my favourite forms of paint are the bottled acrylics from DecoArt, shown below. These are certainly not the richest colours but in all other respects the paint behaves surprisingly well for an inexpensive hobby-paint! Like the Rosco these acrylics are dense but liquid. But in this context it’s perhaps the bottles that have impressed me most of all .. they keep the paint completely where it’s supposed to be and allow it to be dosed in the smallest droplets needed. I’ve never had any leaks from these when carrying them around and when I’ve refilled empty ones with Rosco paint its appeared to keep for much longer.

DecoArt bottle acrylics

I tried to find identical ones online a while ago but couldn’t. But then, once ‘pound shops’ really started to get corporate and become a feature of almost every High Street I came across these in 99p Store, in packs of four as ‘travelling beauty bags’ .. or something like that .. containing shampoo, shower gel etc. They’re the same size as the DecoArt bottles, which hold a little more than 60ml of paint, but always square and made from a slightly harder plastic. I’ve never had the courage to use the contents!

travelling wash bag

But the bottles are almost perfect for paint! .. at least any paint that is liquid enough to be poured into them. Because they’re not quite as squeezable as the DecoArt bottles it’s best if the paint is cut with a small amount of water and .. if you’re familiar with the ‘ketchup bottle jab’, it will help at times! But their squareness is convenient when packing and, I suppose most of all, at 99p for four they’re cheaper than any options I’ve seen online unless you want to buy them in the hundreds.

using 'travelling bag' bottles for paint

As a postscript to this little piece celebrating small plastic bottles! .. I started trying to find out the best ways of preserving the Rosco paint and others that are predisposed to deteriorate and develop mould over time. It may not be simply a case of having to scrape off the mould layer .. the whole consistency of the paint or medium underneath may have altered and become useless. In addition the mould itself may be harmful to health, so it seems to me that prevention from the outset would be far wiser than making do with scraping the mould off as/when it occurs. What for example is it in the paint or medium that ‘goes bad’ in the first place? Is it simply solved by eliminating air contact? .. packing a layer of cling-film down on the paint surface when storing, or pouring a thin layer of distilled water, or even oil, over it? I was given these and other helpful suggestions when I posted the question on the Society of British Theatre Designers facebook page. A little later I received a very helpful confirmation from Jenny Knott, Paint Product Manager for Rosco Laboratories, which is worth quoting in full:

“Most mold/bacteria growth in paint is caused by introducing it into the paint.  Always use a clean, dry utensil to take paint out of the container.  If you use a wet stir stick to scoop the paint out, the water has bacteria in it so it will introduce bacteria into your paint.
If you have mold/bacteria on the paint, scrap all of it off then you can either put a couple of drops of pine oil floated on the top or plastic wrap over the top of the paint surface to seal it from the air.
Another thing you can do is to float distilled water on the top surface of the paint to protect the surface.”
…………………………………………………………………………………………..
In addition I would imagine that the colder the paint can be stored the better .. apart from freezing! I guess that these safeguards work best from the outset and that probably once the medium has become contaminated there’s really nothing that can be done to purify it again and that whatever can be salvaged probably has a short life, if it still works at all. I’d also imagine that all of the above applies to any water-based medium .. I know that it also happens with Idenden texture medium for example. I’ve just added one suggestion of my own which has worked for me so far .. decanting into smaller, separate, sealed containers.