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Brian Whatcott Brian Whatcott is offline
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First recorded activity by BoatBanter: Jul 2006
Posts: 813
Default the raging debate of marine plywood / fiberglassing / etc

On 15 Oct 2006 08:23:29 -0700, "Leaks"
wrote:


kyle wrote:
hi all,

i've been searching through the group .. i keep finding conflicting
opinions.. hoping i can ask my exact question and get an answer


Stitch and glue driftboats are a special case, that make
a good general point, I think.

A driftboat (a dory that drifts down a river) gets its
bottom pounded like no other boat. No matter how
much glass you put over the bottom and chine, cuts
in the glass skin will inevitably expose the plywood.
Then the plywood wicks up moisture, which gets trapped
almost forever, between the glass skins.

Some guys (montana boat builders dot com) have essentially
solved that problem (for stitch and glue boats anyway) by
puting hot spray truck bed liner on the outside.

Another way to deal with it is to use plastic honeycomb core
for the bottom panel, instead of plywood. If you do that, you
need a little extra glass, to stiffen the panel sufficiently.
But when and if the skin gets cut, the moisture does not
wick sideways into the honeycomb.

....


Which reminds me - a Lake patrol man showed me the bottom of his
airboat one day. To allow it to dock right up the ramp onto the hard,
they fitted the bottom with a low friction plate - either high density
polyethylene - or it might even have been teflon.

Brian Whatcott Altus OK