Posted by Jim Macaulay on May 13, 1998 at 13:50:55:
In Reply to: C-Flex to Repair Runabout Floor posted by Jim Williams on May 07, 1998 at 17:10:20:
I'm getting ready to tackle the same job, see my
letter: "Old fiberglass boat" and the answers I
got. I'm skeptical about solid fiberglass for
the floor. In order to be stiff enough, it has to
have some thickness. Fiberglass thick enough to
be as stiff as 1/2" plywood is going to be very
heavy, I think. And a foam core would end up
delaminating under constant foot traffic. I'm
sticking with plywood, but I'll encapsulate it
with 'glass, both sides.
Better check the stringers and transom, and also
the shape of the hull. If it's distorted, you'll
have to force it back into shape, or it'll ride
horribly. The keel must be straight. I'm learning
that it's very common for old 'glass boats to have
these problems, but they can be fixed if you have
time & energy.
Some engineering knowledge: The ridgididty of a
panel is directly proportional to the modulus of
elasticity (stiffness) of the material, but it's
proportional to the CUBE of the thickness!! So the
thickness is far more important than the material.
That's why airplane wing panels have a thick core
of aluminum honeycomb, which is mostly air.