Wednesday, February 18, 2009

Hard work molding

I am still to adjust a style for molding my sculptures. A sculpture made of Chavant Clay is not hard enough to expose it to the public and not a finished work by any means. It takes therefor to make a mold, even a temporary one, to cast its form into something that lasts more such as plaster or metals. So far I have tried with silicone and latex rubbers for the soft mold and plaster or PVC for mother molds (outer shell) to get a mold. That method works fine with small sculptures but with my standing stallion its very difficult.
It all comes done to planning for the final cast. For plaster as final cast, the entire mold has to be lightweight and also made of two parts since plaster cures quite fast. Depending on the mixing ratio with water, plaster can cure as fast as 5 to 10 minutes so you want the mold to be easy to shake and also robust enough to get the cast fill the entire volume well and also take the shape of the initial sculpture.
I've learned the hard way a technique to build a large mold by brushing on the silicone rubber onto to original work, 10 to 20 layers, and then to make the mother mold by casting plaster around in two sections within a molding box. This way I get a molding tool that allows me to cast the sculpture in turf plaster in two steps with a glorious end result