A mold is made in sections out of plaster
and rubber.
Wax is brushed in each of the sections until
the desired thickness is obtained. The wax
will be replaced by bronze so the thickness
of the wax will be the thickness of the
Sections of the mold coated with wax.
Wax bars called “sprues” are attached to
determine where bronze will flow. A
Styrofoam cup acts as a form for a funnel
for the molten bronze.
The wax section with the sprues and cup attached is dipped into a
ceramic slurry, a mixture of silica powder and a colloidal silica binder.
Then it is sprinkled with sand.
This is repeated until the desired thickness is obtained. In this case, 10
coats, which is about 1/2" thick.