I'm getting ready to do some redos on the plywood work on my boat. Nothing
fancy. I do have table saw, router, etc.

Questions: Can I steam and bend a piece of cut plywood to go across the bow
portion of my boat, or will the steaming cause delaminating? A flat piece
won't do, and if I just torque it down, I think it will split. Total
surface area, about two square feet. 3/4" thick high grade plywood, but not
marine.

For the long bench, and a short storage bench, I want to replace what's
there, and put an upholstery cushion on it in segments to access storage
below. Same with the dashboard, again about two sf surface area.

Once I have these cut, what would be the best way to preserve them for long
term? McClosky's? I don't expect these to be dug up by archaeologists some
day, but I would like them to last for about ten years, or at least not turn
to trash in five.

How would you do it? I think I'll stain them dark, just for the look of
them, but what is a good preservative and long term shiny covering that I
won't have to spend a lot of time on to keep up? Polyurethane over
everything? Or would that react?

Steve

On Nov 3, 7:33*pm, "SteveB" wrote:
I'm getting ready to do some redos on the plywood work on my boat. *Nothing
fancy. *I do have table saw, router, etc.

Questions: *Can I steam and bend a piece of cut plywood to go across the bow
portion of my boat, or will the steaming cause delaminating? *A flat piece
won't do, and if I just torque it down, I think it will split. *Total
surface area, about two square feet. *3/4" thick high grade plywood, but not
marine.

For the long bench, and a short storage bench, I want to replace what's
there, and put an upholstery cushion on it in segments to access storage
below. *Same with the dashboard, again about two sf surface area.

Once I have these cut, what would be the best way to preserve them for long
term? *McClosky's? *I don't expect these to be dug up by archaeologists some
day, but I would like them to last for about ten years, or at least not turn
to trash in five.

How would you do it? *I think I'll stain them dark, just for the look of
them, but what is a good preservative and long term shiny covering that I
won't have to spend a lot of time on to keep up? *Polyurethane over
everything? *Or would that react?

Steve

For the storage benches, you should paint them with epoxy and while it
is wet apply 4 ounce/sqyd fiberglass and then paint that with epoxy.
When it is hard, sand it and then apply a good epoxy primer colored
any way you like.
Am not familiar with steaming but I would use foam with 6 Oz glass on
either side. You can order closed cell foam thick enough to be cut to
your curve and then glass it using epoxy. Do not use the old
fiberglass resin, use epoxy.

On Tue, 3 Nov 2009 17:33:12 -0700, "SteveB"
wrote:

Questions: Can I steam and bend a piece of cut plywood to go across the bow
portion of my boat, or will the steaming cause delaminating? A flat piece
won't do, and if I just torque it down, I think it will split. Total
surface area, about two square feet. 3/4" thick high grade plywood, but not
marine.

Gene and Froggie gave you the answer firstest. Thin laminations and
exposy. They build boats this way - big deal 20 years ago - called
cold molding first termed by the Gougeon brothers. West System. I
know a guy who built a catamaran using the technique - it's an amazing
craft.

They are into making inexpensive carbon fiber turbine blades these
days.

That's the best way to do it - in partcular if it's a compound curve.
Steaming isn't hard to do - basically a large PVC pipe, a heat source
for producing steam and a way to prevent pressure build up, but it is
a PITA.

On Nov 3, 9:08 pm, Gene wrote:
On Tue, 3 Nov 2009 17:33:12 -0700, "SteveB"
wrote:

Questions: Can I steam and bend a piece of cut plywood to go across the bow
portion of my boat, or will the steaming cause delaminating?

Probably not your best option. Plywood can be bought in thicknesses
down to 1/64". A glued-up lamination of thin sections of plywood would
accomplish your goal and make splitting or delamination (which I
suspect is very likely) a non-event.
--
It is usually futile to try to talk facts and analysis to people who are
enjoying a sense of moral superiority in their ignorance.
-Thomas Sowell

Grady-White Gulfstream, out of Oak Island, NC.

Homepage
http://pamandgene.tranquilrefuge.net/boating/the_boat/my_boat.htm

Forté Agent 5.00 Build 1171

Gene's solution occurred to me after I posted and that is how the bow
of the Tolman is made to follow a compound curve. So, get some
single ply stuff and bend it to your shape followed by another layer
epoxied to it etc.

In article ,
says...

On Tue, 3 Nov 2009 17:33:12 -0700, "SteveB"
wrote:

Questions: Can I steam and bend a piece of cut plywood to go across the bow
portion of my boat, or will the steaming cause delaminating?

Probably not your best option. Plywood can be bought in thicknesses
down to 1/64". A glued-up lamination of thin sections of plywood would
accomplish your goal and make splitting or delamination (which I
suspect is very likely) a non-event.

3/4 inch is gonna' be tough depending on how much of a bend you need. I
would suggest like Gene said, only use 1/4 inch thickness. Now, because
it lacks voids, you would have a better chance with marine or Occoume
plywood. If you wish to try to bend it, a real steam bend would be
tough. You need constant steam for iirc 15 minutes per quarter inch and
that is not easy unless you have a real steamer and closed box. Plywood
is tough to steam even with that as it's hard to get consistent steam
around the whole surface. Once wood gets soft from steam, even a few
seconds break in the steam will cause the cell walls to set, and they
can not be re-softened, it only happens once. My suggestion is to use
heat and moisture without steaming. Boil some blankets and lay them over
the wood hot and wet and try to bend it slowly like that, without ever
actually softening the cell walls within the wood.

All that being said, I would try the hot blanket first, plywood does
bend ok, sometimes I use a Spanish windlass and bend it over a period of
days or in the case of 2x6's weeks. If that doesn't work, try three
thicknesses of 1/4 inch. Just my $0.02.

Another better source of info might be rec.boats.builders..

Good luck, Scotty from Smallboats.com aka Tosk...

--
Wafa free again.