I'm totally new to all of this, so please forgive my ignorance.
I'm working on a project to create a sculpture 30" high (and about as wide and deep). The master can be made of anything I like, but must be compatible with epxoy resin that will be used to make the mold from the master.
Because of the size, I am using metal rabbit fencing as a structure to support the modeling material (and to check my proportions before I get too involved). Also because of the size, I am concerned about finding a kiln that can fire it.
I need to be able to sand and polish the master to a near-mirror finish for the molding process, then apply a release agent and epoxy resin & fiberglass mat to make the mold.
So - any suggestions on a good material to use? Is there anything that air dries to a hard enough surface to be sanded and polished? (Something that has a long working time, as long as it is kept moist)?