Most thinners contain chlorinated solvents which are worse than MEK. Yes it does soften a not fully cured epoxy surface but it also evaporates somewhat fast so that is not usually a problem. Most blushes are reaction products of moisture and amines and ketones alone do not make it vanish just soften, you have to vipe it off. That is where soaps are sometimes efficient but only with no surfactants. Scotchbrite or equivalent are only good together with some cleaning agent otherwise they just smear the blush around. One way to avoid the blush is to work only in very low moisture conditions (i.e wintertime) when that is not practical a fast cure (warm) also helps to minimize it.

TLM

: I am sure it is going to break down the epoxy a bit, MEK is nasty stuff. when
: i opened the can (with respirator on) I knew that I didn't want anything
: to do with it but tried it any way. The "blush" I think i am
: seeing could be softening caused by the MEK, but I don't think so. It
: seems to look exactly like the blush on other parts of the boat. I want to
: hit it with the scotchbrite and soap or ammonia because that worked well
: on the inside of the hull.

: Thanks for the insight

: Tom