Originally Posted by Jake
There are two more solutions, and in my opinion more reliable options, for curing gelcoat on an exterior surface.

1) Duratec gelcoat additive thins the gelcoat slightly so it will spray a little better and it also acts to promote curing of the gelcoat in open air - you don't need any additional additives to spray and cure. Reportedly the duratec cures the gelcoat harder than it would on it's own.

2) top coat with PVA (poly-vinyl alcohol). After you spray the gelcoat, you can spray a layer of PVA ontop of it to seal it from the air and allow it to cure. The PVA forms a "saran-wrap" esque coating that will peel or wash off easily once everything is cured. It is very water soluable and I use it all the time when I'm molding things to prevent resin from sticking to my molds.


Everything Jake says and... Spraying gel is pretty easy, and gel is very forgiving if you mess up. Definitely use Duratec, and you may need to thin it a bit more to make it flow. Use laquer thinner to thin it instead of styrene. I find that 3%+or- LT makes gel flow much better. Styrene yellows after a few years of UV exposure. You just have to take it a little slower with the coats.

Also, it doesn't take an expensive rig to get a good gel coat finish. Go up to your local Kragen, ect. and pick up one of their cheap gravity guns (no suction feed) on sale for $13.99. I swear you can't tell the difference between my $400 pro auto gun and the cheapo. I'll tell you the difference if I ever have a pot go off in my good gun.

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Surface prep down to 320 is fine. (for most repairs I'll spray over 180 no problem and have sprayed over 80 for a quick and dirty) Once you're done, take it down to 1000 G and buff with this:
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It works magic.

Hope that helps. I'm working od a video right now, but it's going to take some time.

J