Is there any way to fix a window hole that has been cut too large? I removed the window to fix a leak and the removal revealed a hole that was too large. Previous owner replaced the original window (notice it's upside down) and in the process made the hole too large. He used a piece of wood on the inside as a "clamp" and screwed the window to the wood and simply filled the hole with caulk.
. . .
Am I stuck with re-doing the wood mount? or is there a way to replace the fiberglass and "shrink" the hole?
One of the nice things about fiberglass is it's so easy to work with and repair. You can take it to a boat shop, and they can do the work in a few days, or get a book on fiberglass repair and do it yourself.
Me, I'd peel the ensolite inside back several inches, do a coarse sanding job 3-4" out on the outside, strip all the old ensolite adhesive, paint
and wax off. I'd make a luan plywood doorskin template that fills the area you want the fiberglass build up in, plus a second piece that matched the final opening and overlapped the existing inside edge of the fiberglass by 2". From there I'd sandwich a heavy fiberglass cloth between the two pieces of wood, then fiberglass the sandwich into place with two layers of cloth wrapped around both sides of the luan wood build-up at a 45-degree bias to each other and overlapping your trailer's existing fiberglass structure on both sides by 2-3 inches. Then fill, sand, and paint
I'm sure theree are other ways to do it . . . this would be my way.
A simple fix? No, it's a pain in the . . .
Rocket Science? No.
Wear a dust mask and gloves while working wwith fiberglass.