Sealing a hand painted board

Hey y’all, I bought an old beat up surfboard a couple weeks ago and I stripped the old paint off, and hand painted a design on it with acrylic paint. It turned out a lot better than I expected so while I put some clear coat on there, it’d be nice to find something a bit heavier to protect it better. Any ideas? 

Behr Floor and Tile Sealer.  Wipe on two coats.   There are otheres.  I think Minwax makes an acrylic poly.

Thanks! Appreciate the help 

fiberglass and epoxy resin