Just finished the inside of my boat - one layer of glass with one coat of epoxy. I am planning to leave the weave unfilled to create a non-skid effect.

Question: In the past I have always roughed up the epoxy with sandpaper before varnishing. Is this necessary? The epoxy is fairly rough due to the weave of the glass - and the sanding tends to be very superficial, hitting only the high spots. Can I get away without sanding the epoxy first?

Thanks.