Sounds like you're doing it right but acetone should not be used with epoxy, only use Denatured Alcohol (DNA). It is much less aggressive. Acetone residue on the board is breaking the epoxy bonds and causing separation.Also watch your hotcoat thickness - The epoxy needs to be at a certain thickness on the board to maintain a proper surface tension to hold together while curing. Not sure what exact mil thickness but the thicker the better. It will self level and smooth out.A final tip is to not play with the hotcoat. Brush it on then walk away. The more you play with it the more issues you get.