: I have the same problem along parts of the "selvege (sp?) edge of tape that I used along the keel and chines...these appeared when I sanded the edge off (after I scraped the majority of the edge off). The powder doesn't seem to want to come out of these small pockets, even after scrubbing. Maybe I'll have to pick them out with a toothpick or wire coated with something sticky, like resin, and then refill them with epoxy.

How do I know if I still have fiberglass on the hull? It has been sanded to a uniform light gray after 2 fill coats, and I can't see the weave at all (except for the extra layers of tape on the chines and keel. Anyone think I may have gone too far? (6oz cloth, about 5 hours with 80 grit, most of the time spent trying to feather the edges of the extra tape on the keel and chines.). God, I wish I made a test panel first, and deliberately sanded through in places so I would know what it looked like! The hull is as smooth as a baby's bottom, but I hope there is still enough fiberglass there.