What mold release should I use for resin?
Silicone Molds
Silicone molds are naturally non-stick, so most resin artists don't use any release agent. In fact, some mold releases can leave a residue that dulls the surface of your cast. If your silicone mold is new and clean, resin should pop out easily once cured.
However, if you're using a very soft silicone or a complex shape, a light dusting of talc-free baby powder or a specialized silicone mold release can help. Always test on a small piece first.
- No release needed for most silicone molds.
- If needed, use a silicone-specific release spray.
- Avoid oil-based releases that can cloud clear resin.
Other Mold Materials
For plastic, metal, or glass molds, you'll need a release agent. Common options include petroleum jelly (Vaseline), commercial mold release sprays (like those for polyurethane or epoxy), or a thin coat of carnauba wax. Each has pros and cons: petroleum jelly is cheap but can be messy; sprays are easy but may contain solvents that affect resin.
Always read the release agent's compatibility with your resin type. Some releases are designed for epoxy but not UV resin, and vice versa.
- Petroleum jelly: cheap, effective, but can leave residue.
- Commercial mold release spray: easy, but check compatibility.
- Carnauba wax: natural, good for porous molds.
Common mistakes
- Using a release agent on a silicone mold when it's not needed, which can ruin the surface finish.
- Using the wrong type of release (e.g., oil-based) with UV resin, which may prevent curing.
- Not cleaning molds properly between uses, leading to buildup that acts like a poor release.
