Silicone is used to produce durable, flexible molds that won't stick to the object being molded. While there are many silicone products made specifically for mold-making, you can achieve the same results with standard 100% (or outdoor) silicone caulk; it is basically the same product. Using the pour-box method will produce a high-quality silicone mold, as long as the model has no pronounced protrusions that would make it difficult to unmold.
Things You'll Need
- Model to be molded
- Small wood or plastic container to use for a pour box, just large enough to completely surround the model
- Acrylic spray sealer (for wood pour box)
- 1 or more tubes 100% silicone caulk
- Caulk gun
Seal the inside of the pour box with spray acrylic sealer, if it is made of wood. Also seal the model if it is made from a porous material.
Place the model flat-side down in the pour box. Load the tube of caulk in the caulk gun, cut off the tip and break the seal with the scissors.
Squeeze the caulk into the pour box until the model is completely covered. Squeeze as slowly as you can to avoid introducing bubbles into the caulk. Open as many tubes of caulk as needed to fill the pour box.
Allow the caulk to reach full cured hardness, according to manufacturer's specifications (often up to several days).
Invert the pour box so the cured silicone drops out. Carefully remove the model from the silicone.