Don,
Thanks for the input. The epoxy here has cured for well over 2 months. I know the problem you explained, as I've been through that before sanding the epoxy when it was still somewhat green. These white spots showed up by just doing a like hand sanding so I don't think heat was a factor. The glass looked somewhat textured in this area as it does in other spots but when you scuff it with the sand paper this is what happens. Other areas around the cockpit it didn't happen. This spot actually is the smallest, with the other areas being at the peak of the deck just in front of the coaming. That area is where I've been trying to sand away the spots so the pictures weren't as clear to show.