RE: Thinning epoxy with Acetone and adding filler?
Acetone is not only for polyester, it will thin epoxy just fine, is made for thinig epoxy as well as polyester resins and evaporates out better than acohol without leaving any water behind. Warming the resins will also help thin them, but there wil be a shortened working time. Thinning finishing resins can help when working with the very light weight finishing cloths.