Cut four mold walls to match the sides of the bigger piece:
- 2 pieces @ 4 x 15 inches
- 2 pieces @ 4 x 11 inches
Glue up the walls of the mold box with a hot glue gun, applying extra glue at the corners and the "undercarriage" of the mold-- it must be a liquid-tight seal to prevent liquid silicone from seeping out!
Wear rubber gloves when casting with silicone, and be sure to cover your work surface and yourself to protect against messy spills.
Our measurements:
- 2000g part A (tan rubber)
- 200 g part B (red catalyst)
Scrape around the sides and bottom of the tub to make an even mixture. Only when it is all the same color is it ready to pour.
You can trim the edges with a craft knife or scissors. According to the food-safe silicone manufacturer's directions, we baked our finished mold for 4 hours at 212 degrees F, then washed it with regular dish soap.
The LEDs can still be used in projects, just pull them out of the foamcore!