Silt Cast Master : Photo : Cosanti Foundation

The process with silt works in the following way. We pre-moisten and sift silt into a concrete trough. We then take masters made of plaster that are shaped exactly like the bell you are trying to produce. This plaster master is carefully plunged into the silt, forming a conical cavity in that silt. When the master is removed it leaves behind a mold in the silt shaped exactly like the master. After the slip is poured into this type of mold, the process continues normally.

Silt Cast Process : Photo : Cosanti Foundation

There are two main differences between bells cast in plaster and those cast in silt. Since the walls are firm buy not solid, it is possible to make indentations directly into the silt mold walls which also get filled with slip These negative impressions translate into a positive relief pattern on the surface of the bell when it is removed from the mold. This feature cannot be duplicated with the plaster molds since they are solid structures.

Another difference concerns the surface of the silt mold which has a rough texture reflecting the the characteristic of the sand and this feature is picked up by the surface of the bell. The plaster molds have smooth interior surface and its bells also pick up and reflect a smooth surface.

We also produce bells that have a glaze applied to the surface. For this reason we do not apply colored clay powder. Instead of carving designs into the surface we use wooden tools to impress the designs. Glazed bells look better when their designs are impressed rather than carved.