gelcoat over epoxy

mirage

New Member
Hi All,

I am just finishing a cockpit repair. It was soft and cracked so I cut out the floor, cut off the delammed foam core, epoxied and glassed on newe core-cell, replaced the rotted center stringer and glassed in the cockpit sole again. My intention was to spray gelcoat to finish the repair but I have heard and read from several sources that gelcoat will not take over epoxy. Several repair articles on this forum and on Dr. Laser talk of finishing up a repair done with epoxy by gelcoating. Which info is right???The spraying gelcoat idea was partly a learning experiment but maybe I should just paint. I only need to do a 4" wide strip around the floor.
To those out there who have done any major repairs: can I apply gelcoat over epoxy? Do you sugest waxed or non waxed gelcoat.

Bill
 
Gelcoat cures quite nicely over epoxy. The key is to let the epoxy cure completely, remove the amine blush (a wet paper towel works), sand lightly, clean with acetone, and then apply your gelcoat (I've always brushed it on, but people say spraying is better). Finally, you will want to coat the gelcoat with PVA so that it is able to fully cure.
 
yes, polyester based gelcoat will work over epoxy, but only - as stated - when you have removed the amine blush... the acetone is key, otherwise the gelcoat just flakes off, or never dries, or beads up, or, or, or... in the future, you might use polyester resin for your repairs... cheaper, sets faster [if you want it to] and since it smells horrid you know when you have had enough... epoxy is worse for you than resin... fancy that!
 
I think you can get a finish gelcoat which cures fully when exposed to air. It contains wax which rises to the surface so that the gelcoat is sealed. The only thing is that if you're doing multiple coats then you'd need to sand the surface to remove the wax so that the next coat adheres to the previous...

Laters.... it's past my bedtime and if i read some more posts i may feel inclined to hurl my laptop against the wall... Mr Manager wouldn't be too happy with me tomorrow if i did that...
 
I think you can get a finish gelcoat which cures fully when exposed to air. It contains wax which rises to the surface so that the gelcoat is sealed. The only thing is that if you're doing multiple coats then you'd need to sand the surface to remove the wax so that the next coat adheres to the previous...


That's what I like about normal gelcoat, you can keep building the finish a layer at a time until you have it exactly where you want it (which is usually higher than the surrounding area so you can sand it fair). When you are happy with it, you just brush on your PVA and it cures.
 

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