Fiberglass rust repairs are easily available at all local auto body supply store.
Fiberglass sheet metal repair.
Fiberglass is a non corrosive material that can be used as reinforcement or as a repair patch on almost all surfaces including metal plastic and wood.
I used a piece of pvc pipe a vice mount miniature metal break and body hammer kit.
Grind the area of the metal that will be getting fiberglass applied to it using an air grinder.
Power fiber body filler for repair and reconstruction of fiberglass smc sheet moulding compunds parts metal sheet and wood integrating adhesion promoters plasticizers polimeric elements short strand fiberglass and micro fiberglass.
These air bubbles air bombs reduce strength of repair and can also fail leaving a hole in glass and paint or gelcoat.
After slicing the patches out with a cutoff wheel next came the bending hammer and dolly session until the patches matched the holes and fit snug and flush into the flanged seat.
Air bubbles reduce bond and will expand with heat causing future problems.
Once the fiberglass is layed up it should immediately be rolled out with a fin or bubble roller to remove any air trapped in between layers or part.