For easy removal, spray your empty mold with Stoner Mold Release before pouring the epoxy or urethane resin into it. The result is a cast part that releases easily from the mold, allowing you to reuse the mold with minimal degradation. Though originally formulated for casting urethane into urethane molds, Stoner will also work with epoxy resins and silicone molds. However, it is not suitable as a release for silicone to silicone.