Thinning of Gel coat, Someone said they used Lacquer thinner for gel coat. I never had, but I tried it. I have used mek solvent,styrene, Duratec, and Duratec thinner. I think the lacquer thinner worked the best. I have had no clogging of the sand paper when using lacquer thinner. Duratec is good but it adds a lot to the cost and I haven't seen the abilty of the gel coat to resist stain or loss of gloss improved by using it. Their thinner works great but is expensive. I haven't tried the the clearcoat they make but I will at some point.