Question

Metal Shim is used for-

• A. Metal casting
• B. Fiber casting
• C. Mould making of Plaster of Paris
• D. Investment casting

Hint:

Shims are the key to creating multi-part piece molds in plaster. They act as a temporary fence that allows you to pour one section of the mold at a time.

Answer 1

The Correct Option is C

Step 1: Define a shim. A shim is a thin material used to fill small gaps. In mold making, it forms a dividing wall.
Step 2: Understand its use in plaster mold making. When creating a multi-part plaster mold on a model (like a clay sculpture), metal shims (or brass shims) are placed in the clay to create a clean separation. The first plaster mold part is poured up to the shim wall. After removing the shims and applying a release agent, the second mold part is poured against the first, forming a perfect seam. This is specific to piece-molding in plaster.