Q&A

Frequently Asked Mold Release Questions

Q. Do I need to use a release agent to cast urethane resin into a silicone mold?
A. No. Applying a light coating of release agent, however, will greatly extend the life of the mold.

Q. Do I need a release agent to cast silicone into a silicone mold?
A. Yes. Silicones bond to each other. If casting silicone against silicone, you must use Mann Ease Release® 200.

Q. How can I make the surface of my plastic castings more easily paintable?
A. All traces of release agent must be removed using a strong dishwasher detergent (such as Cascade gel) and a solvent. Abrading or “roughing up” the surface (sandblasting) is also helpful when possible. Another option is to “powder coat” the mold before casting.

Q. Why does the surface of my plastic casting seem to be “mottled” or “pitted”?
A. This can be caused by applying too much release agent to the mold.

Q. What is the best method for applying the release agent?
A. Spray on a light mist coating, brush the release over the surface with a clean, dry brush, and then apply a second light mist coating. Allow to dry before casting.

Q. What kind of release agent do I need when casting plaster into a mold?
A. Combine one part dish detergent (such as Joy) with 10 parts water. Then brush the solution over the surface of the mold. Avoid pooling. This will help with the release.

Q. Do I need a release agent when casting wax?
A. No, but a light coating will facilitate the release.

Q. What release do I use when casting urethane foam into a polyurethane mold?
A. Use Mann Ease Release® 2831, which is a non-silicone release agent. A silicone based release agent will mar the surface of the foam.