Epoxy plug?

[mod flod]

Hi, the previous owner of my sailboat changed the deck of the boat while it was sitting in dry storage and drilled a 3/4in. diameter hole at the bottom for drainage. The hull is fiberglass/airex core. From what I read, I should bevel 12:1 on both sides of the core etc but I'm wondering if it's not overkill. Plus, the acces is terrible from outside, upside down work about 1in. from the metal beam that supports the boat. I thought about beveling from inside to the core, molding the outside shape of the hull and filling the outside skin and core portion with epoxy/silica. Would that be enough, considering, again, that it's a 1½in. hole, ¾in. dia. Also, would the epoxy generate too much heat if I pour it in one step? Tanks

[PAR]

A good structural bond would require the care you've described, but filling a small diameter hole in the deck shouldn't need as much attention. Bevel back an area on the skins (both sides of the hole in the 'glass) be generous here as it will be the only real grip this patch will have with the surrounding 'glass work. The larger the bonding area (beveled area) the better the grip for the repairand the less likly the repair will not "come back" . Remove a bit of core material from around the hole, so you have an under cut core in the hole area (helps the epoxy "key" into the repair) Seal the underside of the hole. Tape can work for this, but a cardboard or plywood form, wedged in from below may conform to the curve better. Insure the form doesn't want to stick to your epoxy (clear box tape is good for this) Then wet out inside the hole by brushing on some unthickened epoxy, then using thickened epoxy, fill the hole. When this sets up you'll have some filling and fairing to do, then paint to match.

If you intend to walk on this area or attach any thing reasonably close or through this area, you should try for the 12:1 bevel (yep, both sides) as this will provide a large enough bonding area to be as strong as the surrounding 'glass work, probably stronger. Heat shouldn't be an issue.