(The a-ness of the a)
Firstly, I’m going to test the glazes available. The glazes give the ceramic its colour and lustre, and where some of the magic happens; the glazes are stored in large buckets and look like pale, watery mud – there is very little it the bucket to suggest the final colour. There are helpful colour samples in the glaze room, so I decided to test each one as a basic starter, and then to experiment further when I have some first hand results. The glazes needed a good mixing after being stood over easter (1) before gently dipping each piece in (2) so it just reaches the bottom edge (3) and checking that it’s covered well. One or two got a second dip which will intensify the colours.
And once again into the kiln
And here are the results:
These are all really nice things to hold; they are heavy(ish), each has a very different aesthetic quality which depends upon both the glaze and quality of finish of the clay extrusion, the textures are subtly different in places and exceptionally so in others. These photographs don’t convey this aspect well, so I will seek some photographic advice before shooting the next batch. Anyway, I have these sat upon my kitchen window sill where I can ponder them as I wash the dishes. I often find myself holding them in my spare hand whilst reading too; they are very satisfying objects to fondle. (Do not analyse this!)
Well what about the one not fired? Well, I was working on that during the firing and glazing before, but decided to leave that out until now for continuation purposes. First I made a rubber mould so I could explore casting techniques and materials. Firstly I needed to make a wall to contain the molten rubber from cottling clay (old clay with contaminants from previous castings that are no longer fit for proper ceramic work). This is rolled out into slabs and cut into panels which are assembled on a board to form the perimeter of the mould and hot liquid rubber (vinamould) is slowly poured in. This was heated in a special heater with safety handles and a decent spout – this stuff burns!
The rubber needs a poke and prod to make sure it gets into all the nooks and crannies, as well as a light bang or two on the base and sides to encourage air bubbles to dissipate. After leaving the rubber to set overnight, we prise the original clay letterform out by loosening the edges with a bend of the mould at each corner, and a few slaps on the back.
There you go. I’ve got a mould. Not a good one as it seems. The first attempts to cast anything it tore off the piece that forms the counter hole – obviously it was a weak spot, but it wasn’t straight either, and that prevented the material from leaving the mould without taking it with it!. The material used was called terracotta clay. It’s not actual terracotta, but a type of plaster that is mixed with water to form a thin paste and poured in (just like Plaster of Paris actually). Once set, this stuff looks like, you guessed it, terracotta clay! But, better still, If you place the cast into some water and leave it overnight, the iron in the mix (used to give it it’s reddish colour) begins to rust. After a while the thing looks like cast iron. It even smells like it too!
Ben advised me to halve the depth of the template so prevent the next mould being so fragile so we sawed it in half on the band saw. With one half we made another rubber mould, and the other half, a plaster mould.
Oh boy, and then we started!
So the first one is straight plaster, cast from the rubber mould. Actually, I made two of these – I intend to do something else to the other. This one is a straight cast with no finishing but I am tempted to sand it off a little for a smoother, whiter finish. The next one is rubber. Fresh virgin Vinamold to be precise. If you look back at the rubber mould I made, the colour of the rubber is almost brown as it has a more resilient grade (yellow) added to it for strength. This letter is so squashy and good to handle. It’s a pity it doesn’t smell particularly nice but, hey, you can’t have everything. The next is regular builders plaster mixed with hemp threads made by untwisting twine. Once set, you go over the surface with a wire brush which pulls out the fibres and roughs off a few edges. I also cast second one using the remainder of the mix, and this time added some short cuts of wire into the bottom of mould too. These have rusted a little and begun to stain the surface. I am going to ‘push this one a little to see what happens… The last one here is wax. I’m going to cast anther wax one, this time with fresh clean paraffin wax and add some stuff so you can see parts of it near the surface. Too many ideas, not enough time.
Meanwhile, whilst I had been having fun with the rubber mould, I had been exploring some more clay techniques using the plaster mould, which again needed some attention to put a champher in the sides of the counter piece, as the clay wouldn’t come out from around there.
The first cast was made of a vermicelli style extrusion of clay through a small syringe, then dipped in glaze which was then wiped from the outer surfaces.
I tried casting in slip, a liquid clay, by filling the mould from the slip machine, waiting for 5 minutes and pouring out the excess. This leaves a thin coating on the outer surface of the mould. After more drying, the clay needs to be gently coaxed from the mould. Picking at it, banging it on the bottom, using a heat gun to make it contract more. The first three wouldn’t come out and were consigned to the bin. The fourth one I saved as it was largely intact with some interesting disfigurement and is the first one shown glazed below. Ben suggested sprinkling old clay powder and particles into the mould before adding the slip. This would help prevent the clay sticking to the bottom and let the main surface a more gritty, mottled appearance. Two successful casts later…
So I’ve got more ‘a’s than you can shake a stick at, and some very good ideas of what to do next with hese skill and techniques. But before that I have a few more a’s to make; next time, Raku firing, glass and metal!!!