Pretreating Fiber-Reinforced Epoxy for Coating

Question:

I am the manufacturing engineer in charge of painting. I need your help to perform the following task. I want to paint (spraying or brushing) a fiber-reinforced epoxy resin product with a polyurethane polymer coating. Can you recommend any methods of pretreatment for this surface to achieve good adhesion? Do operations like combustion spray, plasma spray or corona-discharge increase adhesion and are they suitable for this product? K. T.

Answer:

Epoxy resin surfaces are excellent substrates for painting. Therefore, painting fiber-reinforced epoxy products should present no insurmountable problems. As with any substrate, it must be clean (free from dirt and oily soils) before painting. However, I really don't see a need to use combustion spray, plasma spray or corona-discharge pretreatments to prepare the surface.

Since epoxy resin has excellent adhesion to most surfaces, product molds must be coated with a release agent. This mold release, which can be transferred to the molded product, must be removed before painting. Since release agents have many chemistries, I suggest contacting the release agent supplier for his recommendation for its removal.