Materials Porcelain Clay

Michelle, ceramic art studio sounds very cool 8D

Anyhow, your question. Porcelain clay is a bit tricky to work with because, out of all the clays I've used, porcelain has the biggest shrinkage and littlest resistance to warping/cracking. What this means for the sculptor: it is hard to use porcelain to work on a project that happens over time, with variable wall thicknesses, have different moistness in the parts, and so on. For sculpting the originals, I find it is easier to use a grotty clay (clay with lots of sand and bits in it). Grot in sculpting clay is a good thing. After you sculpt the original, you can fire it or or not fire it, and then create plaster molds from that, and *then* cast with porcelain slip. When you cast with porcelain slip, the entire piece has uniform wall thickness, uniform moistness, etc etc, so it's less likely to crack/deform as it dries (still delicate as hell, though).

So that's my experience with porcelain. You should also ask the artists at the studio, Michelle! They'd know much much more than me. And hey, if they have any tips for porcelain, I'd sure like to learn about it.

Also, there are different formulas for porcelain! Some are less likely to warp...but I'll be damned if I know which ones.

Good luck and make the most of it 8D

edit: er, forgot armature.
Making armature for clay projects is actually super forgiving. Because if you plan to fire it, you're going to have to cut your sculpture open and make sure the walls are evenly thick --- your armature is going to come out, and you have to carve so much out of the center that there's no chance for even little bits of loose armature debris to remain in your sculpture. If you do not plan to fire, then you just cut off the parts of the armature that sticks out and begin molding.

So, what material you use just depends on your volume needs. For figurative sculpture, you'll pbb have to use some kind of wire or pipe. Hardware store carry plumbing pipes with all kinds of elbows and connectors. Wires...you can use anything that works, I guess, but you should twist wires together so that the clay has something to grab on to. For bigger volumes, crumpled news paper works just fine. I know some people use wire meshes in part of their armature, but usually it's for big projects (life size and bigger).

Anyhow, good luck 8D

 

Porcelain is a water-based clay, so you must keep it wet while working on it.
That means misting the work-in-progress from time-to-time and
covering it with plastic between working on it.

It seems you are already aware of shrinkage.
There will be shrinkage from the greenware state, to the leather-hard, and bone-dry states.

What you may want to consider doing, is modeling the porcelain over a standard wire armature supported by a modeling stand for sculpture; then, at the early leather-hard state, remove the sculpt from the modeling stand, and cut it apart at the limbs and head, making six doll parts: head, torso, arms and legs. Mold these parts in plaster rough shell molds, or moulage molds. Cast carving wax into the water-saturated plaster rough shell molds, then refine the carving wax doll parts to make patterns for making the final porcelain slip casting molds from plaster. This is similar to Martha Armstrong-Hand's method, except she models the original doll in one piece using oil-clay, not porcelain.

The advantage to using oil-clay as the original modeling material is that it does not dry out or harden. Modeling wax has the same properties. Oil-clay and modeling wax are reusable modeling materials. Porcelain may be reused as a modeling material until it is fired. After firing, it will not return to a plastic state.

Wire armatures are fairly easy to make. Drive a nail partway into your work bench and loop some wire around it. Put the two loose ends in a drill chuck. Operate the drill to twist the wire.

 

I am currently working on my4th and 5th porcelain doll. I haven't yet done any casting using slip and molds but i plan to do so sometime in the future. I sculpt the dolls from porcelain and I have found it to be a very nice smooth clay to work with. Because I work fairly small, I needed to switch to porcelain to get the detail I needed. I don't use any armature because it can't stay in the clay once it gets fired. I tried to put wire in it at first and it blew the head to bits! That is due to different expansion rates. What I do is form each body part separately, hollowing out as I go. Keep everything covered loosely with plastic wrap so it dries very slow. This prevents cracks. I'm just a beginner myself but I have learned a lot along the way and I will share whatever I learned with you.

 

Yes, you can use paper inside and let it burn out but I just let the piece get a little hard and scoop out all the inside softer clay. Very easy.

 

yes, you can use balled up newspaper, and yes, it will burn out in the kiln BUT

You probably should cut up your porcelain piece, dig out the newspaper, and thin the walls to roughly uniform thicknesses before fire, so that your hard work will not blow up in the kiln and take down other people's hard work with it. XD

Balled up newspaper is great to begin building with, but chances are your sculpts will change as you go...and the balled up newspaper that used to be in the center will migrate to some off-center location after a while. It may even migrate the surface on one side, giving you mightily uneven walls. Balled up newspaper can also create air bubbles inside the clay walls with its complicated crumpling action, and air bubbles in kiln = blowing up...

It doesn't mean newspaper centers ALWAYS cause explosions. But just to be safe, you know...