Tips For Making A Large Silicone Mold

Have you ever wondered how to make a large silicone mold of something big? It takes a lot of prep and planning, but the results are worth it.

I show step by step how to make a 13″x19″/33cmx50cm mold with a self sealing laser cut key. The two part mold is constructed with over 5gal/19L of silicone material around the original part. I detail how to secure the original part to it’s platform and line it up in the mold box correctly. I also cover how to set up the second half of the mold as well as how to plan ahead for adding a large enough pour sprue to use with a funnel and have the vents located in the right place.

Once the mold is cured I also show the process of casting a large part in the mold to demonstrate how to cast the final resin piece. In this cast I pour 1.4 liters or Polyurethane resin into the silicone mold to make a vehicle form.