epoxy primer over vinyl ester filler?

[Don C L]

Something is telling me that I should not try painting epoxy primer (Interlux Epoxy Primekote) over "3M Premium filler" (vinyl ester,) but I can't find any mention of it in the labels. Am I imagining it? This is above the waterline.

[Markusm]

Epoxy primer over cured vinyl ester works just fine, however you cannot put vinylester over epoxy primer. Learned this the hard way when I attempted to fair a large section of hull over the top of epoxy primer. I believe the epoxy interacts with the styrene and disrupts the curing process of the vinylester, but if it is already cured, there are no ill effects.

Epoxy primer over vinylester is SOP every year when we do maintenance on my 65' glass over ply charter fishing boat. We have many sections that look perfect after 15+ years of very hard duty.

[AKA-None]

Welcome markusm

[Delfin]

Originally Posted by Don C L

Something is telling me that I should not try painting epoxy primer (Interlux Epoxy Primekote) over "3M Premium filler" (vinyl ester,) but I can't find any mention of it in the labels. Am I imagining it? This is above the waterline.

Been doing it for years. No issues. Typically non-corrosive epoxy based primer over bright steel for repairs, then vinyl ester, then Awlgrip primer, then top coat.

[captlloyd]

Always remember that epoxy is the one that is an adhesive. There will be your answer.

[Don C L]

Originally Posted by captlloyd

Always remember that epoxy is the one that is an adhesive. There will be your answer.

So for a damaged, crazed gelcoat, the epoxy filer is the preferred choice then?

[captlloyd]

Originally Posted by Don C L

So for a damaged, crazed gelcoat, the epoxy filer is the preferred choice then?

That is what I would use after a rough up with sander.

[Don C L]

Originally Posted by captlloyd

That is what I would use after a rough up with sander.

That was the original plan but I had a free can of the vinyl ester filler and gelcoat to repair. I should have mentioned that the filler was going over cracked gelcoat in the first place.
Thanks for the help!