If you've ever applied a coat of epoxy that formed "fisheyes" (round craters) or beaded (like water on a freshly waxed car), you know how hard it is to sand the surface smooth again. And you've probably wondered what caused these irritating defects. Fisheyes and beading seem to result from contamination of the surface under the epoxy — contamination that can be difficult to trace. It may have come from a tack cloth, from an oil or kerosene heater nearby, from contaminated or recycled acetone or other solvent used to wipe the surface, or from someone spraying WD40 or some other chemical in the same room. Keep your work area as solvent- and oil-free as you can to avoid these pitfalls.
