what grit do I sand for gelcoat prep?

[johnnyv49]

Im sanding down the old paint on my boat to get to original gel. What grit should my final sanding be before I spray gelcoat? Im going to 120 right now.

Also when i have shot gelcoat in the past I used no wax and coated with pva. Everyone here seems to be using wax on thier final coat. I always learned that the wax made sanding harder because it clogs the paper. Also I see people using acetone to clean off the wax for sanding. Doesn't that soften the gelcoat creating a new problem?

Whats the best way to shoot gelcoat? Its been a while for me since I resored my mako. Ill be using a cup gun with #6 tip.

 

[Woodonglass]

Re: what grit do I sand for gelcoat prep?

Sooo... currently your boat has paint over the existing gelcoat? If that's the case I'd be a bit more aggressive and use 80 grit to get the paint off a bit quicker. Since you'll be re-Gelling if you burn thru the Gel all the way down to the glass it really won't matter. I'd prolly do a final sanding to 180 grit. Acetone should not soften fully cured gelcoat or polyester resin unless it's left on for an extended amount of time and even then it would take a long time. PVA is often used by members as well as wax. Either will work. PVA requires the timing of application to be somewhat more precise in order for proper curing to occur. I'm certainly NOT a Gelcoat expert by any means, just picked up some knowledge for those that are here on the forum. The Experts will prolly be along shortly to give their advice. Not real familiar with cup guns and the proper tip sizes but I'm sure they will be. Good luck with your project.