Vid-20221228-wa0165.mp4

: If your piece is large, use alignment "dowels" or pins to ensure all sections line up perfectly when mated.

This will help me give you the exact technical steps you need.

If you are preparing a physical object to create a mold, the "solid piece" is often called the :

: Apply a release agent to the master model to prevent it from sticking to the mold material.