[sailingdog]

You need to de-wax the area and then grind it at a 12:1 bevel for the depth of the fiberglass there. If the glass is 1/4" deep, bevel it for 3" all around. and then patch each hole with glass and epoxy, using the West Epoxy method or Don Casey's method. Do the same thing from the other side. Once you're close to a level repair, fair it with thickened epoxy, using wood flour or micro fibers filler, since you'll want it fairly easy to sand. Sand fair. Either prime and paint or apply gelcoat.

Originally Posted by BELLATRIX1965

Greetings all:

The fathometer (a 20-year old Signet) died two weeks after I bought the boat; now the speed log is starting to check out, so I have decided to spring for a nice 3-instrument pod at the helm. Trouble is, I now have four holes in the Aft end of the cabin to fill. All holes are about 4 inches diameter, and I have access to both sides. I've read a lot of threads re: polyester vs. epoxy, and epoxy repair makes the most sense to me. The cabin is solid fiberglass (no balsa or foam core in 1965!!). I'm trying to avoid the tell-tale "old instrument" ring cracks in the back of the cabin after the repair is all fared up and painted pretty! Any advice from those with past experience would be most appreciated. Thanks!