I'm finally able to apply skim coats of epoxy over my hull after a few months of off time.

Before I applied the first "fill the weave and small hollows" coat I roughed up the areas, wiped down w/acetone, scrubbed with warm water and a green scrub pad (no soaps or oils in the pad). I then used my sqeegee and filled the weave and low spots. Not perfect, but it was the first of a couple (I figured). After curing 4 or 5 days I decided to use my fairing board and take off some of the high spots so I could add another skim coat. Well, it seams at the edges of the previously applied skim coat (where the sandpaper went through like it was supposed to on the high spots) the edges are flaking up. It's not really noticable until I wipe down with the warm water and scrub. I can peel super thin layers off. Has this ever happened to anyone here? Is it something I should worry about now, or can I just add another skim coat? At first I thought it might be blush, but wouldn't that get removed w/my prep? Then I thought the acetone, but I wiped down with water and scrubbed.

Thanks for the help. Right now I'm somewhat dejected at the time I've wasted if it all must be ground off.