We build a lot of Glass over foam wings for Radio Control Gliders.
A trick we use to get rid if epoxy weight is to wait a while after we've got a smooth finish than roll out toilet paper off the rol. The amount of pressure you apply while unrolling affects the amount of soakage you get. Wait a bit than carefully peel it back off the glass. I tried this with paper towels on a CLC boat and found it left a slight dimpled pattern. Toilet paper workes best and leaves a smooth finish that does not need scrapping. The Epoxy can not be tacky or you'll never get he paper off.