Behind the scenes

Between clay and cast, there is lot that goes on unseen behind the scenes. Today’s pictures give you an idea in what is involved in taking a mold from the clay torso.

The mold is called a waste mold and for good reason. It is a one-off and must be finally broke into a thousand fragments to release the subsequent plaster master cast. The steps are as follows:

(1) Brass shims are inserted into the clay to give the necessary divisions. In this case, a three piece mold.

(2) Fine Casting Plaster, mixed to the consistency of cream, is them flicked over the clay. The process is achieved by dipping a hand into a bowl of plaster and flicking with the fingers. The process has not changed since the time of Michelangelo. This layer of plaster is no more than a quarter of an inch thick. It is tinted for reasons that will become clear later down the line.

(3) A thicker layer of plaster is then troweled over the figure, level with the shims. Steel reinforcing rods are added to give extra strength.

(4) When the plaster is fully cured, hard wood wedges are driving into the seams to separate the mold.

                       

                       

 The above may sound easy but three days of skilled work is involved. There are scores of intricacies at each step. If anything goes wrong, all is lost. Up to a hundred years ago sculptural mold making was a specialized trade unto itself.

The final picture shows the front section of the mold immediately on removal from the clay. The surface clay is dragged with the mold and hence lost in the process.

A blow-by-blow account of casting the master plaster cast from the waste mold will follow in later posts.