I just did a quick search for information on secondary bonds. I don't know
how authoratitive the one site I saw is but it quoted 2000 psi for epoxy on
old polyester. New polyester itself was only quoted at 500. So, 10 square
inches could lift the boat except that the polyester would give up first.
It would have taken 40 square inches, 6.32 inches on a side, to lift her
the way she was built originally. I'm sure it's not that good in practice
but even if it's way, way, off....

--
Roger Long