On Jul 6, 5:22*pm, Wayne B wrote:
On Wed, 6 Jul 2011 06:16:43 -0700 (PDT), jamesgangnc

wrote:
Some newer boats
use fiberglass I beams as stringers with no wood at all.

I used to own a boat called a Winner 24. *It was a *cuddy cabin
runabout built in 1978. *The stringers were fiberglass laid over a
foam core and were still like new when I got rid of it several years
ago.

The only purpose of the foam was to create a temporary frame for the
fiberglass to be laid up on. The foam doesn't contribute to the final
results and it doesn't matter what happens to it. The fiberglass is
essentially the stringer. In some cases with wood encapsulated
stringers you end up with the same thing. There is so much fiberglass
that it doesn't matter much what happens to the wood. Particularly on
older boats where they used to really lay on a lot of glass. The
problems come about in situations where the builder was trying to keep
the boat light and on larger boats. Fresh water boats are worse as
salt water acts as a wood preservative. And all the wood eventually
will get wet. Screws holes are the worst sources of water penetration
but polyester fiberglass is not water proof so even a perfectly
encapsulated piece of wood will eventually get wet if the outside is
routinely exposed to water. Epoxy is a far better product to use for
encapsulating wood but it costs many times what polyester resin
costs. A lot more builders today are leaving wood out entirely.
David Pascoe has a lot of great information out there on what goes
wrong with wood/fiberglass boats.