Mike" wrote in message
...
Use a self tapping screw and JB weld. Clean area real good .Rough the
surface.
Tap hole. Apply a generous load of JB and insert screw. Apply excess over
the top of everything to seal it up for good.

With a self tapper there is always the possibility of setting up a galvanic
cell inside, and speeding up the corrosion. I'd go for mesh and epoxy
outside (where the epoxy also keeps oxygenated water off the mesh, so that
even if there is a dissimilar metal pair connected, there's no oxygen).