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 piece of material used to fill small gaps or spaces between objects. In mold making, it is used to create a dividing wall.
Step 2: Understand its use in plaster mold making. When making a multi-part plaster mold directly on a model (e.g., a clay sculpture), thin pieces of metal called "metal shims" (or brass shims) are inserted into the clay to create a clean separation line. The first part of the plaster mold is poured up to this shim wall. The shims are then removed, a release agent is applied, and the second part of the mold is poured against the first, creating a perfect seam. This technique is specific to piece-molding in plaster.