Hi Guys; Yes, I did do the seams with glass. Matter of fact , the
hull had a layer of glass/epoxy, over a brushed on epoxy layer...I had
good luck with the paddle which was made the same way by laying a ply
with wax paper along the backside of the blade, then trowelled a bunch
of milled glass/epoxy to the edge, then sanded to shape. That has held
up famously . I wish I could same the same of the hatches that are of
lauan doorskin bent to shape over wood formers. They seem to have
occasional damage along the edges that allowed the water to wick
through the end grain and doing the damage. Am considering grinding to
a knife edge, then clamping the waxed ply backing to conform to the
edge, then doing the same epoxy/milled glass along the edge to toughen
and seal the edge concurrently. Yep, I'm on the cheap side. I thought
the the first couple boats I'd build were going to be trial horses
anyway so don't invest the bucks. Considering the lack of care I've
shown the oats, I'm considering building another using the same
(cheap) methods. Pat

Hi,

When building with non-marine ply, try boiling an offcut to test for
delamination.

Also protect plywood end grain that's vulnerable to damage with a
strip of durable timber.

cheers,
Pete.

Pete C wrote:

When building with non-marine ply, try boiling an offcut to test for
delamination.

I have seen this advice a few places, and I know that to qualify for marine
grade, plywood has to survive some heavy boiling tests. But I don't
understand what boiling has to do with endurance in marine environment.
Most of us don't sail in waters anywhere near boiling temperature.

-H

On Tue, 27 May 2008 00:24:00 +0200, Heikki wrote:

Pete C wrote:

When building with non-marine ply, try boiling an offcut to test for
delamination.

I have seen this advice a few places, and I know that to qualify for marine
grade, plywood has to survive some heavy boiling tests. But I don't
understand what boiling has to do with endurance in marine environment.
Most of us don't sail in waters anywhere near boiling temperature.

-H

Boiling speeds up the breakdown process so you can find out quickly if
the ply is any good. A better test would be to make up samples and
leave them in the expected enviroment for a few years to see if it
will stand up but nobody wants to wait that long.

What if he used "Gorilla Glue " on the exposed edges ?

Phil wrote:

What if he used "Gorilla Glue " on the exposed edges ?

It's hydroscopic - absorbs water.

Not exactly what you would want for a waterproofer.

Richard

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John Wayne

"cavelamb himself" wrote in message
...
Phil wrote:

What if he used "Gorilla Glue " on the exposed edges ?

It's hydroscopic - absorbs water.
I understand that but doesn't it become waterproof when it's cured? I
haven't tried it but that stuff seems to go into porous surfaces very
easily.

Phil wrote:

"cavelamb himself" wrote in message
...

Phil wrote:

What if he used "Gorilla Glue " on the exposed edges ?


It's hydroscopic - absorbs water.

I understand that but doesn't it become waterproof when it's cured? I
haven't tried it but that stuff seems to go into porous surfaces very
easily.


No, over time exposure to water will destroy the strength of the bond.

Richard

--
(remove the X to email)

Now just why the HELL do I have to press 1 for English?
John Wayne