Quote:
Originally Posted by Cape Codder
. . . Is there a depth i should drill out or should I just drill until I hit the bottom later of glass? And what size drill bit would you use?
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I'd recommend mounting it like I did the brackets for my galley seat, which can have some significant loads on it in rough seas when occupied by a large passenger! Use machine screws instead of self tapping/sheet metal screws! (The threads on self tapping screws are much sharper than machine screws and tend to cut fiberglass if there is any relative motion!)
1. Use a large drill bit, like 1/2"-5/8".
2. Drill CAREFULLY until it hits the lower sheet of glass, which is only 1 layer (~1/16") thick! If it's a Potter hull with original deck, it's 1/2" balsa core.
3. Fill hole with thickened epoxy.
4. Redrill hole for a 1/4-20 machine screw, using a 3/16" drill. (0.1875" diameter; minor diameter of a 1/4-20 internal thread is 0.196"). Countersink top of hole to assist in starting tap.
5. Tap hole using a 1/4-20 tap. Or you can just cut a slot in a 1/4-20 screw and use that for a tap, as the epoxy is pretty easy to cut.