I can't get to the back of the structure to fasten a plate with
bolts. This is the fasten this type of chair mount:

http://www.overtons.com/modperl/prod...ID=1009&r=view

It is going on the glassed in plywood over foam floor of a deckboat.

I'm thinking some type of high end sealer in predrilled holes and on
the screws will do the trick.

Thanks!