Seems like it's standard practice to sand the glassed exterior before applying a fill coat. Why sand? I understand it is probably necessary to remove some excess epoxy, BUT if one were extremely careful to squeegee it off while wet or scrape it while green, would it still be necessary to sand before doing the fill coat?

I thought the idea was to avoid sanding into the glass, and if the exterior weave texture is already evident and uniform, wouldn't it be difficult to avoid sanding into the glass?

(Yes, I'm going to have to sand anyway, where the edges of double layers at the stern and bow are obvious. The rest came out really nice and bubble-free, thanks to using foam rollers followed by squeegeeing. Gotta glass the deck next, and then it'll look like a kayak :-) )