By Don Casey
Revised by BoatUS editors in April 2012
The resins in paints and the resins used to build fiberglass boats are chemically similar, too similar for most paint strippers to notice the difference. That means hardware-store paint strippers will dissolve your boat. There are strippers specifically formulated for use on fiberglass--the only kind you should contemplate using--but my experience has been that even these can damage gelcoat if you leave them on too long.
So if you use a stripper on fiberglass, don't make the mistake of thinking that leaving it on longer will be better. Chemical strippers can be used safely on wood surfaces and are very good at removing varnish and other wood coatings. However, avoid strippers containing methylene chloride, an extremely hazardous chemical. There are health-friendlier alternatives.