Art of Statue Making Explained by Sculptor, 1940. I design a statue and having it cast is a difficult job stated Hermon A. MacNeil. First he makes a model in plastic clay. He makes four models and then he chooses one and from that the bronze is cast. He uses French sand and that means a mixture of sand, clay, silica and alumina. It is pressed into every crevice of the plaster model, pressed in small pieces, into an ear, for instance, that it can be taken out without harm to itself or the model. These are placed into iron frames, clamped together. Background is important.