I would like to know more about poplar plywood.
We did build a small test boat from it (our FL11) and in the shop it looks
like a great material.
It is light and strong, does not split, bends well and absorbs resin quite
well, a very good point for epoxy encapsulated boats.
It is a renewable resource and inexpensive.
The mechanical characteristics are perfect for our applications.
Several professional kayak builders and WEST Systems speak favorably of
poplar. I am certain that it is great plywood for small skiffs, kayaks,
canoes etc. That point is granted.
It may work for some of our sport fishing designs too but here comes the
question:
How is the resistance to rot and the moisture intake when used in a boat
that stays in the water for long periods of time? I am looking at hulls that
are completely epoxy saturated and fiberglassed, where the plywood is a
core, not plain wooden boats.
I just fiberglassed some scrap poplar plywood, will paint the samples and
sink them under my dock for a few months to measure changes but I would love
to hear from builders with real world experience.
Does anybody have a boat build from poplar plywood and how is it doing?
Serious answers only please: no flames from "know-it-all" people claiming
that this a stupid idea etc.
I did my research and compiled a good amount of data about it. No need to
tell me that there are different types of poplar, populus and tulipifera or
what the bending moment is. What I don't have is information about boats
build with that material.

Thank you in advance.

--
Jacques
http://www.bateau.com

Not familiar with poplar plywood that actually has poplar as a veneer, but I
am familiar with poplar in "hardwood" form as well as poplar core plywoods
(with other hardwood veneers). In general, poplar is one of the woods you
simply do not reach for when building anything that may be exposed to
water/moisture. Poplar is a popular wood as a secondary wood for the sides
and backs of dresser/desk drawers, as good trim that will be painted in a
house and in general, it's used anywhere there's a requirement for hardwood,
good machinability and paint. While I'm sure you can encapsulate it with
resin etc, if moisture does fond the actual wood (and it always does), rapid
rot is not a possibility, it's a suretly.

Other woods that typically don't find their way to wet uses include maple,
alder, red oak etc....

Good luck
Rob


"Jacques Mertens" wrote in message
...
I would like to know more about poplar plywood.
We did build a small test boat from it (our FL11) and in the shop it looks
like a great material.
It is light and strong, does not split, bends well and absorbs resin quite
well, a very good point for epoxy encapsulated boats.
It is a renewable resource and inexpensive.
The mechanical characteristics are perfect for our applications.
Several professional kayak builders and WEST Systems speak favorably of
poplar. I am certain that it is great plywood for small skiffs, kayaks,
canoes etc. That point is granted.
It may work for some of our sport fishing designs too but here comes the
question:
How is the resistance to rot and the moisture intake when used in a boat
that stays in the water for long periods of time? I am looking at hulls
that
are completely epoxy saturated and fiberglassed, where the plywood is a
core, not plain wooden boats.
I just fiberglassed some scrap poplar plywood, will paint the samples and
sink them under my dock for a few months to measure changes but I would
love
to hear from builders with real world experience.
Does anybody have a boat build from poplar plywood and how is it doing?
Serious answers only please: no flames from "know-it-all" people claiming
that this a stupid idea etc.
I did my research and compiled a good amount of data about it. No need to
tell me that there are different types of poplar, populus and tulipifera
or
what the bending moment is. What I don't have is information about boats
build with that material.

Thank you in advance.

--
Jacques
http://www.bateau.com

Let me take that a little further... Poplar will suck up water like a
sponge if it can find it and will swell and distort. I would not
consider it a good wood for holding fasteners either... My advice to
the pro, dump the stock, run away from this post, and hope the subject
never comes up again... no disrespect intended Jaques', and remember,
this is ONLY my opinion.
Scotty from SmallBoats.com

The poplar plywood I am testing is listed here as "marine" plywood:
http://www.worldpanel.com/eurolite.htm

I don't expect much distortion from a 5 ply 6mm ply with melamine glue,
saturated with epoxy and fiberglassed.
This is plywood used as a core and hasn't much to do with wooden boats
technology.
I agree that poplar is not a proper material for a wooden boat hull but
balsa or foam aren't either. Very large and good boats are build from balsa
and foam.
Poplar has better characteristics than those core materials but it absorbs
moisture.
I have concerns about moisture and that is why I posted the question.
I have seen boats with balsa strips (not Contourcore) as a core.
Balsa also absorbs moisture too and is more tender than poplar but those
boats last. Why not poplar?
At which point will it's moisture content stabilize in an epoxy matrix?

It is already used in wood -epoxy construction, WEST systems endorse it for
some applications:
http://www.westsystem.com/webpages/e...8/plywood.html
Poplar is used for aircraft ply and gest a MIL spec. It is tested for shear
resistance after a 3 hour boil test. Not exactly a sponge.
I know that this applies to poplar with an Okoume face but shear resistance
is all in the core, in the poplar.
I also know of some kayak builders who had great succes with poplar and if
it could be used for larger boats, that would be great.
Don't misunderstand: I am playing the devil's advocate here. I keep an open
mind about it and I am not ready to endorse it for such applications. I may
if my tests come out positive, I may not if I read about some bad
experiences.

Thanks for your opinions and I would like to read more.

--
Jacques
http://www.bateau.com

"Backyard Renegade" wrote in message
...
Let me take that a little further... Poplar will suck up water like a
sponge if it can find it and will swell and distort. I would not
consider it a good wood for holding fasteners either... My advice to
the pro, dump the stock, run away from this post, and hope the subject
never comes up again... no disrespect intended Jaques', and remember,
this is ONLY my opinion.
Scotty from SmallBoats.com