ORIGINAL: MaxThrottle
If its just reducing foam rash and dings Polycrylic like Minwax is very easy to brush on. I light especially if sprayed or brushed on in thin coats.
Its not structural though. For that fine fibre glass and epoxy thinned with isopropanol. The isopropanol evapourates as it sets. Then lots of sanding. Then repaint.
My experience had been start looking into composite/fibre bodies.
I would avoid Isopropyl and use Denatured. Isopropyl has water in it and tends to leave a film after it dries and I would bet that would affect the way the epoxy cures. I've always used Denatured when glassing with epoxy (and waterproofing boat hulls). Lately I've been using water-based polyurethane for glassing and applying silkspan (yup, I do that sometimes) and have been extremely happy with it. It's not as durable as epoxy, but it's lightweight, easy to sand and cleans up with water... and the smell isn't nearly as bad.
-Frank