What if I am using a two-part resin system?
If adding to an epoxy resin system, it is generally advised to add the internal to the less viscous component, resin or hardener, before mixing the two components.
If adding to a polyurethane resin system, it is generally advised to add the internal to the polyol component, before adding the isocyanate.
In the case of two-part resin systems, it should be noted that 1.0 phr means 1 part of internal mold release to 100 parts of the two-part resin mixture (resin + hardener).