Repair delamination in fiberglass wallby John White
John offered this solution to a forum member who had a motorhome with delamination over an area of 10" X 12" of the outer wall.
Park the RV next to a wall or rigid fence.
Drill holes along the top of the delamination area and then alternate spaces going down to the bottom of the delamination. Using the large syringe, inject the finishing resin into the top holes until it starts to appear at the holes below. Continue injecting resin and moving down the delamination area until the bottom holes are showing the resin coming out. You can wipe off any excess while applying pressure to the RV wall.
Place the sheet of plastic over the delamination area, followed by the board, then wedge the board against the repair using the lengths of 2x4 and wedges. Allow the resin to cure overnight.