Re: Epoxy trouble

Posted by LeeG on Aug 30, 2004

Sounds like a little amine blush developed in the humidity with too much time between second and third coats with sanding just moved it around. Sanding is best done to fully cured epoxy that's been washed and dried. If your third coat went on marginally cured epoxy that had a little blush then what you describe sounds like "fish-eyes". People say all the time "it must be contamination" which is possible but even under ideal conditions epoxy has weird surface tension characteristics as it's curing. Applying one coat after another just as the previous gets tack free can work most of the time but if it's very humid then amine blush will start developing. MAS slow cure is especially good(not developing blush) in this regard but even then the weird surface tension can result in fisheyes when you do everything right. You can write off bad coating to "contamination" when you see a pattern of fisheyes that approximates the pattern of a wiped material or greasy fingerprints (pizza fingers)but when it's EVERYWHERE I think you're in the twilight zone of epoxy laminating adhesive being used as a surface coating. There are epoxy paints and there is epoxy laminating adhesive. Making the laminating adhesive act like a paint doesn't always work perfectly.

In Response to: Re: Epoxy trouble by Aaron J. on Aug 30, 2004