Good questions. I still struggle with the whole process, but in a perfect world, you would have sanded the boat fair with your fairing board and it is smooth. Apply the glass and wetout just enough to fill both the wood and glass, the glass will be flat on the wood surface, no floating due to too much epoxy in some areas.

I can not see the valleys or bumps without sanding with a fairing board (80 grit), if needed add coat of epoxy with squeegie to level the low spots. Sand again till fair, then apply varnish, sand again only with 220 on the first couple of coats then 320 on last 1 or 2 coats.

The application of the glass and the first layup dictates how much work you will do in the following days to fair without low spots. I believe the 20 minute interval from mixing and applying the epoxy, to coming back and squeeging the excess epoxy out is the most important for leveling the glass and getting rid of excess epoxy.

David just finished sanding and applying 3rd coat perfection varnish Hanson