Expert: Leisha Hiester - 9/30/2008

Question
I want to reuse my off cut terra cotta clay.  i have pulverized the dry off cuts and then soaked them.  I want to add something?? to this to make it a thick slurry that i can trowel into large plaster moulds.  Any clues?

Answer
Peter,

I also recycle my clay! I congratulate you on one green step in your studio.

Are you trying to thicken up your slip? Generally, plaster will suck the moisture right out of recycled clay. Do you have a plaster bat for recycling? I made one quickly by purchasing a large flat plastic tub, the type you store sweaters in under the bed. I filled it 3/4 way with plaster. It has handles & a lid on it for easy moving around in my studio.

If you're talking about viscosity & deflocculants, that's another matter. There's a good book out there, "The Slip Book" that may be a big help to you.
Sodium silicate is a common deflocculant, but use sparingly. Hope this helps. Feel free to write again. I know, slipping can be slippery, ha.

Leisha