I would suggest that when ever possiable that a backing plate--or lacking that, a fender washer be under any stenchon post. I understand the glassed over problem--one solution is to back out the bolt, then get a Dremel tool, or die grinder with a flexiable shaft and cut/grind off the fiberglass. Probably there was a layer of matt put over the hull to deck joint. Lacking that, you can thicken epoxy with cabasol (silica) to a consistancy which will not run thru the bottom. I would suggest that you wax the machine screw before inserting it into the epoxy. Thus you should (no guarantee) be able to back it out some time in the future. One concern is that although the epoxy will fill the hole, there may be some loose glass or wood in the way of the hole and adhesion might not be optimal??? I set stenchon posts in 5200. If you have to cut them off with a wire or bond release later, OK---but done properly they will last a long time. Good luck Bob Austin