Surface Contamination

Posted by CLC on Apr 19, 2006

I think it was coincidence that you encountered "fisheyes" as a thunderstorm was coming over the horizon. Surface contamination is the likely culprit, and a lot of things could do it. A wipe-down with an oily rag, exhaust from a clothes dryer, particles of lubricants from overhead garage door tracks.

On humidity: It takes a LOT of humidity to create problems with epoxy surface adhesion. I can think of two recent examples where heavy fog rolled over boats being built in open-sided carports, at the same moment that a fresh coat of epoxy was curing. This caused the no-blush epoxy to blush and thus subsequent coats to "fisheye."

Folks concerned about "fisheyes" and surface contamination between coats of epoxy can innoculate themselves from problems by wiping down surfaces with denatured alcohol or lacquer thinner before applying the next coat. Use a clean rag, and don't use paint thinner, mineral spirits, or acetone.

In Response to: Problem by Tim on Apr 18, 2006

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