Damage to the exterior of a fiberglass RV shell is a common occurrence with regularly used recreational vehicles. The constant maneuvering of an RV in and out of campgrounds and tight spots or while storing at home makes bumping into something and causing damage all too likely. Once damage happens to the RV fiberglass exterior, it is important to repair it promptly to seal out moisture and debris. Fortunately, minor damage to the fiberglass exterior of an RV is easy to repair at home. Using a few inexpensive supplies you can patch holes, gouge and scrape marks, and fix cracks.
Cut a portion of fiberglass cloth into a size that completely covers the area of the RV that is damaged. If the damaged area is too large for a single piece of fiberglass, cut enough pieces that when used together will cover the damage. Keep fiberglass handy.
Paint a generous layer of mixed polyester resin directly onto the damaged fiberglass exterior of the RV and the area immediately surrounding the damage. But only paint as large an area as you can cover with the fiberglass cloth. Work in small stages so that the resin does not dry before you have time to apply the fiberglass cloth, which needs to be laid smoothly across the area to be repaired.