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.

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.

"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.

Use some Chinese tools, burn some Chinese bulbs, drive a chinese car, and
then make your decision. Remember, most of the time you get what you pay
for.

Kevin

I was out paddling a new plywood box this week as soon as the ice was off
the pond. I like the really cheap virola underlayment from Home Depot for
it's light weigth and flexibility and use if for boatbuilding but don't
recommend it. After paddling around in the pond for an hour or so I
noticed a crack in the thin face ply on the bottom about 4 ft long. At
home I poked a blade into the crack and found it was a longitudinal seam
between two sheets of veneer. Looks like the face veneers were not edge
glued so I scraped out the seam and after leaving it to dry for a day
filled it with epoxy mixed with home made wood flour.

Virola is not from China. It's from Brazil.


--
------------------------------------------------------------------------------
William R Watt National Capital FreeNet Ottawa's free community network
homepage: www.ncf.ca/~ag384/top.htm
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Right, but what's your "mission?" I've been reasonably satisfied with most
Chinese tools, by:

- regarding them as expendable

- ignoring aesthetics

A case in point, my angle grinders, on sale for about ten dollars (vs Bosch
at $70). They sound terrible (square cut gears), and they get hot, but they
remove weld metal and I don't cry when I drop one.

I'm a hobbyist. If I were trying to earn a living with them, it would be a
different matter.

Roger

http://home.earthlink.net/~derbyrm

"Kevin Gunther" wrote in message
...
Use some Chinese tools, burn some Chinese bulbs, drive a chinese car,
and then make your decision. Remember, most of the time you get what
you pay for.

Roger Derby wrote:
Right, but what's your "mission?" I've been reasonably satisfied
with most
Chinese tools, by:

- regarding them as expendable

- ignoring aesthetics

A case in point, my angle grinders, on sale for about ten dollars (vs
Bosch
at $70). They sound terrible (square cut gears), and they get hot,
but they
remove weld metal and I don't cry when I drop one.

I'm a hobbyist. If I were trying to earn a living with them, it
would be a
different matter.

Roger

http://home.earthlink.net/~derbyrm

"Kevin Gunther" wrote in message
...
Use some Chinese tools, burn some Chinese bulbs, drive a chinese
car,
and then make your decision. Remember, most of the time you get
what
you pay for.

I guess I am what you might consider an "extreme hobbiest" then. But I
still insist on high end tools. The ten dollar grinder will not be
balanced like the Bosch or Porter Cable so it will leave rings and will
lead to much more hand sanding, and a loss of much material and time.
Even if you are a hobbiest, you want your project to be good, weather
it is aesthetics, structural integerity, whatever, you will have a
better project with better tools. We are very particular from baseball
gloves, to computer printers, to athletic socks, we find that life is
easier with better tools, it just is.

As to the plywood question, it fits the mold. If you want no voids,
repaired knots, and thin skins, go with marine plywood. If you want to
have a piece of material that is all that, no rubber plugs, equal plys,
and it bends fair (no interior knots) and stays well, etc.. Go with
something rated as BS1088. Not only is it structurally superior, but it
makes working the wood a pleasure instead of blasting through that
yellowpine splintered crap they sell as marine ply now adays.. Just a
rant, Scotty

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.

I built my MiniCups from cheapo plywood bathroom underlayment and now I
regret it. Should have used marine ply. The underlayment has serious
voids and places where there seems to be no glue. It isnt exactly
waterproof either and water soaks right through. I am now glass and
epoxy reinforcing them. The dinghy I built with marine ply seems very
strong with no voids. Of course, it is also painted with epoxy.
I would not willingly buy anything from China as their politics suck, I
object to slave labor and support the self determination of Taiwan.
Sorry about the political rant.

Brian D wrote:
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.

At a plant tour in HuangPu (I won't mention what company was involved), they
showed us how nice the employee apartments were. Apparently, they bring
folks in from out in the country to work at low wages in the city. The
"apartments" had a store and various other things, but after awhile we
noticed that there were no families, no kids. The workers charge against
their paychecks. Looked like indentured slaves to me (22 cents per hour was
a typical labor rate). I've seen more than one analysis that claims there
is about to be a labor revolution in China ...these people are tired of
doing all the work, getting low pay and no benefits, and they aren't going
to do it anymore. The unrest is growing. When all costs are considered,
manufacturing in China is only 30-40% cheaper than in the US ...the pendulum
will come back, don't worry. Times are changing. And if you're too worried
about China being a super power economically, consider how fast it can
change when the economics change, or if they get uppity and threaten Taiwan
too much (or actually do something about it.) Here's a couple of clues: a)
How many products are invented by the Chinese, then produced in China, then
sold world wide ...versus how many are invented somewhere else but are
*manufactured* in China? b) How many American or European companies are
investing in China, paying for the building of factories and buildings with
their own money? and c) How many western nations offer mutual funds and
other investment vehicles that focus on the Chinese economy? It's a paper
tiger, friends. They invent nothing on their own and the primary attraction
is cheap labor that'll likely go away. If the cheap labor folks get more
money, then it won't take much to equalize the cost of business, there
versus here, and the happy happy joy joy ride will be over. In spite of
oodles of companies doing manufacturing over there, note that investors vote
against investing in China. Last I heard, only one company could be found
that had Chinese investment funds that you could participate in. The
investors understand the risk ...and the risk will return the work to other
locations. (I'm betting on eastern Europe, Brazil, Argentina, Chile, etc.
....NOT western Europe and the United States.) The EU is stable and the US
is on a slide... damn fools.

Brian D



wrote in message
oups.com...
I built my MiniCups from cheapo plywood bathroom underlayment and now I
regret it. Should have used marine ply. The underlayment has serious
voids and places where there seems to be no glue. It isnt exactly
waterproof either and water soaks right through. I am now glass and
epoxy reinforcing them. The dinghy I built with marine ply seems very
strong with no voids. Of course, it is also painted with epoxy.
I would not willingly buy anything from China as their politics suck, I
object to slave labor and support the self determination of Taiwan.
Sorry about the political rant.

Brian D wrote:
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.

1. Andrew's Canadian underlayment did not come from China. If he bought it
at Rona it is meranti and came from south Asia somewhere. If he bought it
at Home Depot is is virola and came from Brazil. I've used both and nothing
else on all 4 of my small boats with no complaints given the low price and
light weight. I'd rather pay $13 a sheet for underlayment than $50 for
marine and do a bit of maintnenace. If you fill the voids and seal the
edges lauan or meranti lasts reasonably well for a few years without
sheathing in resin-saturated fibreglass, or just coating with resin alone.
If you watn a boat to pass on to your grandchildren, use marine ply.

2. Labour costs in North America and Europe are out of sight and need to
come down. The whole object of the violent union demonstrations at the
Seattle WTO conferene was to try and impose quotas against lower cost
goods from countries where labour costs are lower. The US unions bussed in
thousands of people to throw rocks at police officers. It worked because
Clinton was up for re-election and imposed quotas. Extortionist labour
unions scuttled the WTO negotations and kept people in lower wage countrys
from getting work. North Amercian unions don't give a damn about working
conditions in China. It's just a propaganda ploy to keep wages high in
North America. It's not a matter of wages in other countries going up but
of wages in North Amercia and Europe coming down. We will see unions
fighting dirty so their members can drive around in SUV's and get free CAT
scans whenever they fell like it, but eventually wages will come down,
even if it's just a matter of imporing all goods and leaving the low pay
retail jobs to locals, or the US ecomony will fail. Yes, the unions are
spreading malicious propaganda about "workers rights" overseas and about
job loses at home, because wages have been so good that North Amercian
unions have lost their reason for being and lost so many members they are
at their lowest point in decades. They are trying to scare people to build
up their membership again.

As for China it is going through what Japan went through after WWII when
they started selling cheap goods abroad to test markets. Older
boatbuilders will remember when "made in japan" meant popor quality. No
more. Now "Made in USA" means poor quality compared to "Made in Japan".
Once the Japanese established markets offshore their economy took off for
decades until they let it heat up too much and the rapid rate of growth
eventually leveled off when their economy matured, leaving them with a
mountain of insupporatble debt.

All of which has little to do with boatbuilding outside of the price of
plywood and cheap Pacific knockoff's of popular big boat designs..

--
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homepage: www.ncf.ca/~ag384/top.htm
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