Steve, Glad your experiences have been different than mine over the last 12 years. I also use acetone on many projects but just wanted to pass on to the less informed some potential problems with its use. I suppose that when I've worked on so many different boats over the years I'd run across many different circumstances and results. Yes sanding does remove gelcoat, but some times it just has to be done to please an owner. In those cases I do it wet; 600 to 1200 grit, then compound and buff to 2000, seal and wax. Also, as jr stated, gelcoat is much thicker than paint. Typically, when gelcoat is sprayed into a mold, it is done in three cross passes at 7 mils each, horizontally, vertically and diagonally for a finished thickness of 21 mils. Now , this all depends on the application tech.. If he's conscientious then it should be pretty uniform, but even then there are areas that can be difficult to reach so that at times some areas may be thicker or thinner. Many times I've started a small repair that turned into a larger repair because almost immediately surrounding gelcoat was sanded through due to insufficient thickness. Therefore, I'd say that unless you're willing to do more work than you thought you had to do I'd leave sanding as a last resort.