I'm brand new to fiberglassing, so I'd love to pick your collective brains before I mess up. :-)

I had a little crack on the hull bow piece that needed to be reinforced. Yesterday I did a practice piece of fiberglass cloth on a spare piece of wood and it went on so easily and smoothly I just went ahead and did the piece on the crack. It, too, went on easily.

After it had hardened, I looked at the practice piece and it had some frayed edges and strings on the sides. I sanded the entire thing, trying to feather the edges into the wood. The entire thing got a little white with sanding, which I expect is normal. When I wet it, it seemed to fade again, so it looks like subsequent coats of epoxy would make it clear again. The strings and frayed looking edges were REALLY white, though, and stayed white even when wet. And the sanding seemed to take off the frayed edge but made a new one in its place, getting me nowhere.

I thought I could sand away the threads and get a sharp edge, but that doesn't seem to be the case. So what's the deal with the edges? I haven't touched the patch piece yet and want to be sure of what I'm doing first.

Thanks,

Patsy