On the run up to Christmas I had a vague notion of making some Krampus ornaments for the tree. I started looking into resin casting and lost wax techniques, got excited, and then realised they’d take quite a bit of research and investment in materials before I could try them. Option 2 was to create a mould from a sculpt and then use some kind of air-drying clay to produce cheaper copies. However, all the air-drying clays and paper clays I’d tried in the past were a bit rubbish. Then I stumbled across ‘cold porcelain’ which looked for all the world like some kind of air-drying sculpey, but made from cheap common household materials. Must be worth a go, right?
I tried this recipe: http://www.puffylittlethings.com/homemade-cold-porcelain-clay/ which uses corn-starch, PVA, oil, and lemon juice or vinegar. It’s worth watching the video beforehand so you know what to expect: my old 800W microwave took considerably more fifteen-second zaps than the recipe says to get the gloop to the right consistency. After seven or eight I took it out of the bowl and started trying to knead it, but despite liberally dusting everything with corn-starch it immediately stuck to my fingers in a gloopy mess and refused to behave. I gave up, washed my hands, and came back to watch the video again because I was so worried that it just wasn’t working. It’s worth persevering though: I zapped it a few more times and then tried to ignore the bits that stuck to my fingertips while I kneaded the lump for 10 minutes or so, and at the end I had something like a very soft sculpey. I didn’t manage to get any photos of the process (hands covered in the stuff) but I’ll have a go next time.
I started small and made a lump-with-rabbit-ears to see how the stuff behaved. I followed it with a tiny rose: adding a bit of acrylic paint in to give the colour. It didn’t work brilliantly. The main problem was that the cold porcelain was too soft so the petals started to droop as I worked on them and I ended up with a slightly bloopy rose. Still- it dried fairy quickly and the result was quite strong- something like super sculpey but without that brittle feel.
A little experimentation later I tried sculpting a couple of heads. Turns out cold porcelain’s great for ears and horns. The chap on the right turned out quite well, but in the background you can see my second attempt which looks a bit like a grumpy axolotl with horns… For these larger pieces I found the air-drying nature of the clay a bit of a drawback. As I worked, the outer layer dried to a leathery consistency but underneath the CP was still very malleable, resulting in a face that slowly squished and distorted the longer I held it in any direction. The leathery outer layer would bunch and wrinkle, and it was nigh impossible to fix once it’d happened. Hence axolotl-face there.
I also tried using one of my old Cthulhu silicone moulds to see if I could use CP that way. Air-drying inconsistencies struck again as the base (the only part exposed to the air) dried and warped while the rest stayed wet. After a day nothing had changed so I carefully extracted him and let him dry outside the mould before giving him a coat of paint. He’s cute in an artefact weathered-by-time kind of way. I think CP + moulds could work, but the moulds will have to be shallow to allow the air to get to as much as possible.
The warping seems to be a pretty major problem unless I want to start producing wrinkly monster dolls (not impossible, but also not quite what I was planning). I started making another face for a krampus-esque visage, but after a few minutes he started to warp and go bug-eyed. I stopped, leaving eyes and nose on a head-shaped blob. A couple of days later I came back and tried adding to the cured CP. I expected it to detach as it dried and shrunk, but surprisingly it seems to work. Here’s the result so far- he still looks pretty weird as the first half warped, but as an experiment it’s definitely been useful: