My 1975 SeaCraft 25' Seafari rebuild thread

[hermco]

I think the knees and 1/4" inside thickness are overkill, but I agree that lapping the cloth around into the hull bottom and sides is a good idea. That glass between the plies may add a bit of compressive strength but it adds NO bending strength to the transom because it's at the neutral axis. (When you bend an I-beam, the compressive and tensile stresses are directly proportional to the distance from the neutral axis, which is at the center of a symmetrical part, so there is NO bending stress at the neutral axis. A cored panel is similar to an I-beam, so the max bending stresses are at the outer surface. This is why cored panels can be so stiff and strong with relatively weak and lightweight core materials like foam.

You are exactly right!