Originally Posted by CB Haws
MEK will attack gelcoat while acetone has a much lesser effect.
So I shouldn't use MEK as a cleaner for gelcoat then? What I'm trying to clean is some kind of residue that is around all the windows - it's like whatever they used to try to seal the windows dissolved and spread out all over the gelcoat. When I rub it with a little MEK on a rag it comes off. Acetone doesn't work at all. Neither does denatured alcohol or any of the normal cleaners (like bleach, simple green, bartenders friend, etc.) I haven't tried lacquer thinner yet.