Plain plaster will work! You can buy casting plaster at Home Depot in
25 lb bags.

Soapstone is easy to work, but dulls tools fairly rapidly. The local
highschool art classes use wood working tools to do scuptures out of
soapstone. Not as well known is the fact that you can use soapstone
powder somewhat like powdered metal. Mold it and compress it, then
sinter it. It is how the better vacuum tube sockets were made.


Dan