When you say "China", I think "yeah, right". There is absolutely nothing
guaranteed about Chinese quality. They can and will cheat whenever they
can. They are still a communist country and are very difficult to deal with
legally. I'm not just spouting off ...I work for a blue-chip high tech firm
and we've had to chase down exactly these issues ...provision of products
not meeting specifications or quality requirements, using substandard
materials rather than what we asked for, not protecting intellectual
property (confidential disclosures, nondisclosure agreements, patents, etc
are not respected), and using Kopy Kat materials and products from Chinese
companies that are illegally copying and violating the patents owned by
western nations. Chasing things down legally is an expensive dead-end.
Like I said, it's a big communist country that has little intention to be
influenced by your concerns, even if they are ethically correct and the
country WOULD benefit by cooperating with rather than ignoring your
concerns. Taiwan is little better.

That said, I would not trust the adhesives in plywood from China to always
be correct. I would boil test a sample from every piece of plywood that I
got and personally inspect the wood itself too. You might find variation in
wood species in addition to variation in what adhesive they used. To a
slightly lesser extent, these same issues apply to wood obtained from 3rd
world countries like the Philippines and Malaysia too. Wood from Europe,
Israel, Canada, or the United States will in general NOT have these issues,
but keep in mind that much of the available wood (especially Meranti, Lauan,
and Honduras or Philippine Mahogany) is imported from the countries that
have more of a quality issue than others. Also, check your ply for
squareness ...many of these other countries just don't have high enough
quality control and non-rectangular plywood is common. Even the more
reliable countries are getting more slack on producing nice rectangular
wood.

All wood should be encapsulated with epoxy to waterproof it, and any species
that may be subject to splitting or checking would benefit from at least a
light layer of fiberglass, even if only 1-1/2 ounces.

Brian D




"Danielle Anderson" wrote in message
.. .
Waterproffing is not the problem here. Pretty much ALL plywood is made
with
waterproof glue. Marine plywood is about the highest grade of plywood due
to it's ridgid spec requirement. Most plywood contains numerous cracks,
voids, and large knots in the interior laminations. Often they will be
repaired on the outside layers only. Marine plywood has very few cracks,
NO
voids, and knots must be under 1/2 inch. Pay the extra money and only do
the job once. Cut this cost corner at extreme risk of failure.

Jon


"Pop" wrote in message
...
Has anyone used the 1/2 in. plywood from China, Home Depot has this but
it
is interior grade, colud it be used for boat building if it was
completely
sheathed in a waterproof material.