Don't know if I can thin w/mineral spirits - I know the epoxies can be thinned with acetone and acetone disolves foam of any kind like acid (ever pour acetone into a styrofpam cup ? Pours straight through the bottom !) As far as the 2K, I want a high build anyway, 3-4 or more heavy coats, enough to block sand it out straight. My assumption is regardless how uneven the finish is, if there's onough material to block down straight, I get the same results as spray.