The bolts on the rail are staggered, one inboard, one outboard. The inboard ones could take a backing plate or large washer but the outboard one appears to be directly over or into the hull topsides. Yesterday, I spoke with a guy at Gougeon Brothers, the makers of West System products. It turns out that I do have a copy of the manual but it''s outdated. He suggested that I over drill the holes, fill them with
epoxy using the smallest amount of thickener possible (for better flow around the bolts), coat the bolt with mold release wax. Set a nut on both the bottom of the bolt and at the top just at deck level, set the bolt and nut asembly into the wet expoxy and let cure, then back out the bolts. The nuts will then be solidly incased in
epoxy and should withstand the torque needed to tighten down the rail and stanchion. He said that both tapping a hole or self tapping screws create micro cracks in the
epoxy and will weaken the bond. He suggested always bonding bolts directly in
epoxy whenever possibble. I guess it all sounds reasonable to me so I may give it a try.
Thanks again for the help,
Steve