Epoxy surface coat (in place of polyester tooling gel)

[1offNSX]

I have had some intermittent de-lamination issues with using epoxy resin for the laminations on top of a polyester tooling gel coat in mold construction. Seems like the variation in the hardening and shrinkage were the culprit.

I was experimenting using a thicker viscosity epoxy with an added pigment has a surface coat and the thinner epoxy for the sequential reinforcement laminations. Both viscosity resins use the same hardener and set up time.

It seems like the mold construction is more stable and the surface finish is very nice.

Any pros/cons to using epoxy as a gel coat?

[hojo]

Originally Posted by 1offNSX I have had some intermittent de-lamination issues with using epoxy resin for the laminations on top of a polyester tooling gel coat in mold construction. Seems like the variation in the hardening and shrinkage were the culprit. I was experimenting using a thicker viscosity epoxy with an added pigment has a surface coat and the thinner epoxy for the sequential reinforcement laminations. Both viscosity resins use the same hardener and set up time. It seems like the mold construction is more stable and the surface finish is very nice. Any pros/cons to using epoxy as a gel coat?

Epoxy surface coat will be much tougher and have a much better bond than the polyester gelocat. I would suggest though buying actual tooling epoxy surface coat rather than making your own. Only downfall is you cant spray it.