| www.smooth-on.com for more mold making and casting videos, galleries, and materials. Mold Making Minute: 2-Part Mold Making The original model is a plastic sphere. The 2-part mold should be split along the horizontal axis. Process Overview 1: One half of model is embedded in clay 2: The first half of the mold is poured and allowed to fully cure 3: The mold is turned over and clay is removed 4: Release agent is sprayed to prevent bonding 5: The second half of the mold is poured The mold is allowed to fully cure prior to demolding. Making the First Half Build a mold box. Seal seams with hot glue. Secure with a mold strap. The model must first be partially embedded in clay. Begin by building a clay bed inside the box. Press the model into the clay bed until only the top half is exposed. Use more clay to fill in any open spaces. Level the clay surface to the model's midpoint. Flatten and smooth the clay surface. Embed small acorn nuts in the clay; reason: creates registration keys between mold halves. Mold Star 15 1:1 Low Viscosity Platinum Silicone Dispense equal amounts 1A:1B by volume. Dispense parts A and B into mixing container. Mix parts A and B as directed. Slowly pour into one corner of the mold box. Pour 1/2 inch (1.25 cm) over model's high point. Allow Mold Star 15 to cure. Making the Second Half Begin by removing the mold box. Turn the mold over and remove the clay. Do not remove the model from the mold. Carefully remove the acorn nuts without removing the model ... |
