Do I need mold release for silicone molds with Deep Pour Epoxy?

No. UltraClear Deep Pour Epoxy works great in standard silicone molds and does not stick to the silicone, so no release spray or powder is needed. Mix it correctly, let it cure fully for 3 days, and the piece demolds as normal.

If a casting is hard to get out, first check that you mixed and cured the epoxy per the instructions. If you did, and the mold is one you made yourself, the problem is the mold, not the epoxy: the epoxy has never had an issue with standard silicone molds in all our years supplying it. If a homemade mold is fading, getting brittle or tearing when you pull a part, use a different mold; standard silicone molds are available from Amazon or other storefronts. We can only advise on the epoxy, not on mold making. One epoxy-side change that may help: if a 1.5" pour is generating a lot of heat, split it into two 3/4" pours 12 to 24 hours apart.

Leaked epoxy or bits of mold material stuck to a demolded piece can be sanded off. To recoat, sand-scuff with 220 to 320 grit, wipe off the dust with a clean rag and denatured alcohol or acetone, and pour a fresh coat; it fills the scratches and cures clear again. Deep Pour Epoxy is only for pours at least 1/4" deep, so for a thin coat over a sanded casting use UltraClear Bar & Table Top Epoxy instead.

Deep Pour instructions: https://ultraclear.helpscoutdocs.com/article/840-deep-pour-epoxy-instructions Tutorial videos: https://www.bestbartopepoxy.com/tutorial-videos/