Acetone is wickedly flameable so be careful. Burns clean. Also need a well ventilated area. On a few occasions I got light-headed borderline sick from smelling acetone fumes and I thought I was being careful so watch out. Otherwise, good stuff. If I have a worthy penny that I'm about to soak, I'll grab a few similar pennies and test soak them first just to see if anything bad happens. Rare but I have seen a penny dull in luster from a soak so always best to test on a similar coin first.























