How to Make That Old RV Fiberglass Shine Like New

Concrete sealer is very similar to acrylic finishes like Polyglo, or Red Max Prot or Zep Wet Shine. There are lots of threads on here about restoring oxidized fiberglas with those products - do a search. Best application I have tried is a spray bottle - use it like you would cleaning the kitchen counter - spray a bit on and immediately wipe almost dry with a soft cloth - multiple light coats is the trick.