Painting over an epoxy coated hull

[Jason Connellee]

Guys/Gals,

How long should I wait before I prime my boat hull that I glassed with epoxy resin ?

[Sean B.]

I know there are others here more experienced than me, but I'll give my input.

depends on the resin system, temperature and humidity (though, not so much humidity)

best to read the can (bucket, drum, etc) of the resin and hardener... there should be at least 3 times listed...

pot life
set time
full cure

I think most epoxies are 24-48 hour full cure (assuming you don't have a means of baking it to accelerate cure time)
Personally, I would add a day to the cure time... use that day to finalize prep (sanding, tack and washdown)

[jimslade]

7 days at 70 degrees.

[JR-Shine]

A FULL cure could take up to a week. I have primed/painted over epoxy in 48 hours with no problem. Most epoxies do not have an issue with shrinkage, but some (especially epoxy based primers) need a full cure before you paint. If paint dries over still curing (and possibly shrinking) epoxy you risk “mud cracks” in the paint. The manufacturer of the epoxy should be able to tell you.

Joel