sealing plywood end grain?
 

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

sealing plywood end grain?
 

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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(remove the X to email)

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

sealing plywood end grain?
 

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

sealing plywood end grain?
 

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.

sealing plywood end grain?
 

"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.

sealing plywood end grain?
 

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

sealing plywood end grain?
 

Brian Nystrom wrote:
cavelamb himself wrote:

Brian Nystrom wrote:

patrick mitchel wrote:

a stitch and glue kayak made from lauan ply (the cheap doorskin/non
waterproof). Kept under cover in the mild southern california
coastal climes. Showing delam in the areas where the ply has
extensive exposure to end grain (cockpit coaming, hatches). Also
occasional splits on the sides where impacts have occurred and
allowed to open a bit. What's the best strategy to keep splitting to
a minimum (yeah, I know, marine grade ply. Aint gonna happen- not in
the budget.) When building the boat might the best strategy have
been a couple layers of thinned epoxy to penetrate the end grain and
flat surfaces given me a better chance of not having to deal with
this fairly minor problem (considering the age of the boat is
approaching 10 yr old) It was fun to build the boats and the one
that spent the majority of it's life in a garage looks a lot better
in the splitting dept (or the lack of splits). Thanks Pat



You've answered your own questions. Build the boat with the right
materials (marine grade ply) and seal it with epoxy. Is the boat
sheathed in fiberglass? If not, it should be.

The bottom line is that if you build a boat to last, it will. If you
build it cheap, you have to regard it as disposable and/or expect to
repair it frequently. You can't have it both ways.



You may also want to check the manufacturers data with regards to
thinning epoxy. Most of them say don't do it.


My understanding is that thinning epoxy just makes it porous when it
cures, as the evaporating solvent leaves behind passages in the epoxy.

I'd guess that you could thin epoxy with about 10% (max) solvent by
volume without much of a problem.

It wouldn't surprise me if the reason manufacturers don't advocate much
more than this is primarily because the environmental police would come
after them for releasing to much solvent vapor.

Boden

sealing plywood end grain?
 

I'd seal the end grain with acrylicexterior latex paint.

Best stuff.

On Jun 8, 10:46*am, Boden wrote:
Brian Nystrom wrote:
cavelamb himself wrote:

Brian Nystrom wrote:

patrick mitchel wrote:

a stitch and glue kayak made from lauan ply (the cheap doorskin/non
waterproof). Kept under cover in the mild southern california
coastal climes. Showing delam in the areas where the ply has
extensive exposure *to end grain (cockpit coaming, hatches). Also
occasional *splits on the sides where impacts have occurred and
allowed to open a bit. What's the best strategy to keep splitting to
a minimum (yeah, I know, marine grade ply. Aint gonna happen- not in
the budget.) When building the boat might the best strategy have
been a couple layers of thinned epoxy to penetrate the end grain and
flat surfaces given me a better chance of not having to deal with
this fairly minor problem *(considering the age of the boat is
approaching 10 yr old) It was fun to build the boats and the one
that spent the majority of it's life in a garage looks a lot better
in the splitting dept (or the lack of splits). Thanks Pat

You've answered your own questions. Build the boat with the right
materials (marine grade ply) and seal it with epoxy. Is the boat
sheathed in fiberglass? If not, it should be.

The bottom line is that if you build a boat to last, it will. If you
build it cheap, you have to regard it as disposable and/or expect to
repair it frequently. You can't have it both ways.

You may also want to check the manufacturers data with regards to
thinning epoxy. *Most of them say don't do it.

My understanding is that thinning epoxy just makes it porous when it
cures, as the evaporating solvent leaves behind passages in the epoxy.

I'd guess that you could thin epoxy with about 10% (max) solvent by
volume without much of a problem.

It wouldn't surprise me if the reason manufacturers don't advocate much
more than this is primarily because the environmental police would come
after them for releasing to much solvent vapor.

Boden