Gelcoat over epoxy primer?

[Joe W]

I recently bought a late seventies 23 cc from a local boat shop. I am in the process of putting the boat back together. I would like to spray gelcoat on the deck and inside the hull. There is paint on the deck that the owner of the boat yard said was awlgrip epoxy primer. Can I spray gelcoat over this primer?

[shine]

In general, polyester (gelcoat) does not bond well or at all to epoxy. Topcoat is a much better finish coating than gelcoat by any measure.

[Joe W]

Thanks for the reply. I also asked a couple of local boat shops and the answer is a unanimous no.

[TPG]

West Systems will vehemently disagree that you can't put gelcoat over epoxy. Its a mechanical bond, not a chemical bond, so your mileage may vary.

[Normagain]

Yeah, I've done two boats with epoxy and both sprayed and rolled gel coat on after reading the West data and it sticks great. I have waited for the epoxy to cure for a few weeks, washed and wet sanded, then used course sandpaper. No problems. Only used the jgreer epoxy so test first! Epoxy primer is a different animal though, might not work. Never try it directly over System 3 Quickfair, it will absolutely not cure.

[flyingfrizzle]

The way most people work around this is to use a VE biased primer over the epoxy then gel over that. The ve is compatible with epoxy somewhat and then the gel is somewhat compatible with the ve. I would just do a Good Quality top coat tho. Think you would be better off.