What am I missing

[bluwateronly]

Got a question for the fiberglass pro's. I see you are supposed to de-wax the fiberglass before grinding. The guestion is if you have paint over the glass, as most work I come across, how do you de-wax before grinding when you can't apply the stuff on top of the paint? Most of the guys around here say just grind it to good glass and your fine. From what I have read is don't grind till you have de-waxed first. I have had no problem with the resin and glass sticking if I grind to the raw fiberglass but, want to know what the pro's do. Yes, I am going nuts waiting for a good sail day here in S.F. bay. It has been very light winds and I do not like to motor so, I have been getting alot of work done on the old girl.

[mitiempo]

If the paint was well attached to the fiberglass you can assume that it was dewaxed before painting. Just grind back to raw glass and wipe with acetone to remove any contaminants after grinding. The wax you would normally be worried about is what has been used in the mold for release. I first used glass and polyester in 1969 and have been using West and other brands of epoxy for over 20 years on different boats and have never had an issue of adhesion either inside the hull or outside.

[bluwateronly]

Thanks Mitiempo, thanks for the confirm, thought that's what's up but, had to ask.