[Ritchard]

if you can get some chopped strand mat and make 3 or 4 little circles to fill the hole you're patching, that would be better. Wet them out thoroughly and stack them neatly in the hole. The foregoing sounds easier than it is.

I've not read Mainesail's article, but I have found that the shrink wrap plastic that is filling boatyard dumpsters everywhere this time of year makes a great backing material for filling a hole. It's got some body to it, and epoxy will not stick. Put a sheet against the hull, back that further with a piece of plywood, and jam it all in place with a stick and a wedge.

Edit to add: Holy heck that's a manly pile of bronze.

 

[Ritchard]

I am just thinking that some chopped mat added to your thickened epoxy makes that part of the repair much stronger. Remember, epoxy hasn't much mechanical strength on its own. It's the glass that gives it all the strength. Woven mat would work too, it's just not as easy to work with or malleable in such a circumstance.

I imagine you are proceeding sort of like the "low stress hole" in the West Systems link, where you'll plug the hole, fair the outside, and back up the inside with a couple of layers of glass. My contribution just makes that plug a little better.