My boat is fiberglass construction, false floor, completely encapsulated seats. What I am trying to do is fasten a seat base to the first bench seat that is strong enough to carry a automotive seat, (van Captains chair with base removed), and me. I'm a large guy, so there is a lot of stress on the base. I was thinking of using toggel bolts and *PL premium* to fasten plywood to the top of the boat's seat and building from there. My concern with that is the load will be distributed over the small surface area of the toggels. Aproximatley 4 square inches. Once I have wood, I can do anything I need to. (Not meant as a brag, just my material of choice)
There is no way of getting to the interior of the seat to put plywood underneath.
I thank you in advance for your advice.