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Another Gelcoat Question

Posted: Nov 9th, '20, 17:56
by JohnV8r
Hey Guys,

Sanded the new exhaust on Shambala with 400 through 800 grit sandpaper over the weekend. Polished a couple of spots. Pretty happy with the results with one exception. Because I had to roll out the gelcoat in the boatyard, I knew there was likely going to be a thin seam on the inside radius of the exhaust and the very outside edge on the exhaust opening. Sure enough, by the time I got the orange peel sanded up I had sanded through a couple of spots on the exhaust.

My question is what the best method for covering this area would be. I am limited to rolling the gelcoat on in the boatyard (although I'm at the point where I just may sneak my HVLP gun in and shoot it anyway). Should I be trying to cover this with un-thinned gelcoat or can I use patch booster to thin and use a small paint brush to brush a couple of coats on the thin areas?

Image

Thanks,

JohnV8r

Re: Another Gelcoat Question

Posted: Nov 9th, '20, 20:58
by Raybo Marine NY
Preval sprayer . Have a heat gun handy to warm the preval up. They changed the propellant again recently they really hate being even a little cold and hate being held on an angle when full. Once you start spraying they get cold also. Will spit out ice which no matter how much you try to bury will show up as porosity later

Re: Another Gelcoat Question

Posted: Nov 9th, '20, 22:45
by JohnV8r
Wow, that is AWESOME! I had never even heard of a Preval sprayer. I'm all over it. Thanks Rob!!!

Re: Another Gelcoat Question

Posted: Nov 12th, '20, 18:30
by Pete Fallon
JohnV8ER.
Gel Coat is very, very temperature sensitive. You should wait until the air and hull temps are over 50 degrees for a couple of days or inside a heated shop/barn. 72 degrees is the best temp for doing gel coat. Gel coat will not flow well below 50 degrees and try and warm it to sounding air temp. Prevail bottles are great for small jobs and available almost everywhere. Below 50 your going to have orange peel and air voids, if it works at all.
Pete Fallon.

Re: Another Gelcoat Question

Posted: Dec 9th, '20, 15:11
by JohnV8r
Thanks Pete! We're having interesting weather out here right now. Temps have been mid-60's during the day for a 2-3 hour period, but dropping off quickly with lows in the high 30's to low 40's. I have a flame throwing propane heater that I have used in my garage to get temps up to 85 degrees. I may take that down to "preheat" the hull somewhat in the morning to maximize the 60 degree window. If that doesn't work, I'll wait until spring. It's just a little touch up work.

Re: Another Gelcoat Question

Posted: Dec 10th, '20, 18:52
by Raybo Marine NY
if it faces the sun you will be ok, sprayed gelcoat down to 40 degrees just have it finished earlier in the day so it cures up a bit before the evening

Re: Another Gelcoat Question

Posted: Dec 14th, '20, 01:29
by JohnV8r
Thanks Rob! I'll give it a shot.