: What I have found is that if you sand into glass with a coarse
: grit, often the weave does not want to wet out or wet our well.
: If you wet sand it with very fine grit like 300 going up to 600
: you will see the glass disappear. The advantage of wet sanding
: is that you are wetting out as you sand and can see how it wets
: out. Glass doesn't care if it's varnish, epoxy or water.
: Sometimes if you're sanding in preparation for varnish and you
: expose the weave, wet sand the area very fine and you can see it
: wet out. Better to do that than have a bad surprise if the
: varnish doesn't wet it out.

: I also learned that if I'm in doubt about wether glass needs
: another coat or not, I use epoxy. It's harder, weighs the same
: and is ready to sand in days.

I've had good luck using a Purdy paint scrapper with a slighly convex carbon steel edge where the 2 layers meet. It cuts the glass edge of the second layer cleanly, reducing the amount of epoxy fill and sanding time......even though I love to sand (not!)

Bryan K