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Kevin December 24th 03 06:07 PM

Steam Bending Plywood
 
Well I tried to bend 6mm plywood around my buck (As described in a
previous thread), and after steaming it for almost an hour, got
absolutely no where. As I can not find 2mm or 3mm okoume any where
locally, and shipping it seems pretty prohibitive ($50.00 packaging
fee for one sheet???!!).... I have found a source for 1.5mm Finnish
Baltic Birch 3 ply (AirCraft Grade) in 4' x 4' sheets. The supplier
says it can be rolled and shipped via ups in a mailing tube.... so I
guess it can be made to conform to my buck. Anyone aware of any
reasons not to "cold mold" several layers of baltic birch ply? It will
be epoxy, four layers of 1.5mm baltic birch glued with epoxy (I am
hopping that the epoxy in between the birch will fill out the sandwich
a little for a 9mm width) and a layer of 6oz fibre glass on the
outside.....

I can however buy 4mm 3 ply bs1088 okoume locally, but am wary of
being able to bend it after steaming to my desired radius.

comments appreciated.

Kevin

Brian Whatcott December 24th 03 06:34 PM

Steam Bending Plywood
 
I'm sure the laminated birch ply will work for you, but then you could
go the whole hog with cloth, chopped strand and cloth for a piece
that will last rather longer than any wood can hope for...
Wrap a shiny plastic film overall while setting, for that gloss finish
you would like....

Brian W

On 24 Dec 2003 10:07:43 -0800, (Kevin) wrote:

Well I tried to bend 6mm plywood around my buck (As described in a
previous thread), and after steaming it for almost an hour, got
absolutely no where. As I can not find 2mm or 3mm okoume any where
locally, and shipping it seems pretty prohibitive ($50.00 packaging
fee for one sheet???!!).... I have found a source for 1.5mm Finnish
Baltic Birch 3 ply (AirCraft Grade) in 4' x 4' sheets. The supplier
says it can be rolled and shipped via ups in a mailing tube.... so I
guess it can be made to conform to my buck. Anyone aware of any
reasons not to "cold mold" several layers of baltic birch ply? It will
be epoxy, four layers of 1.5mm baltic birch glued with epoxy (I am
hopping that the epoxy in between the birch will fill out the sandwich
a little for a 9mm width) and a layer of 6oz fibre glass on the
outside.....

I can however buy 4mm 3 ply bs1088 okoume locally, but am wary of
being able to bend it after steaming to my desired radius.

comments appreciated.

Kevin



Kevin December 24th 03 10:39 PM

Steam Bending Plywood
 
Brian,
The problem with that is... well straight glass just won't match well
with the overall wood based theme of the boat. I want the nice grain
and wood color in the inside... and showing through the wetted out
glass on the outside.

Kevin

Brian Whatcott wrote in message . ..
I'm sure the laminated birch ply will work for you, but then you could
go the whole hog with cloth, chopped strand and cloth for a piece
that will last rather longer than any wood can hope for...
Wrap a shiny plastic film overall while setting, for that gloss finish
you would like....

Brian W


RG December 25th 03 01:41 PM

Steam Bending Plywood
 
Perhaps a sheet of 1.5 mm on the inside; and another on the outside..and
glass all the way through??? That way you get the wood appearance, and the
glass strength and longevity. Your materials can be "mailed in a tube" too.
RichG



Trent Hink December 25th 03 09:52 PM

Steam Bending Plywood
 
Are you sure you can't get 3mm baltic birch ply locally?
It seems to be very popular for making drawer bottoms. Cheap and strong too.
I think 3mm should be flexible enough to cold mould the way you want.


"Kevin" wrote in message
om...
Well I tried to bend 6mm plywood around my buck (As described in a
previous thread), and after steaming it for almost an hour, got
absolutely no where. As I can not find 2mm or 3mm okoume any where
locally, and shipping it seems pretty prohibitive ($50.00 packaging
fee for one sheet???!!).... I have found a source for 1.5mm Finnish
Baltic Birch 3 ply (AirCraft Grade) in 4' x 4' sheets. The supplier
says it can be rolled and shipped via ups in a mailing tube.... so I
guess it can be made to conform to my buck. Anyone aware of any
reasons not to "cold mold" several layers of baltic birch ply? It will
be epoxy, four layers of 1.5mm baltic birch glued with epoxy (I am
hopping that the epoxy in between the birch will fill out the sandwich
a little for a 9mm width) and a layer of 6oz fibre glass on the
outside.....

I can however buy 4mm 3 ply bs1088 okoume locally, but am wary of
being able to bend it after steaming to my desired radius.

comments appreciated.

Kevin




Kevin December 26th 03 04:32 PM

Steam Bending Plywood
 
The problem with the local 3mm baltic birch that I have been able to
find is that it only has interior grade glue.... which I don't think
will hold up.

Kevin

"Trent Hink" wrote in message ...
Are you sure you can't get 3mm baltic birch ply locally?
It seems to be very popular for making drawer bottoms. Cheap and strong too.
I think 3mm should be flexible enough to cold mould the way you want.


Glenn Ashmore December 26th 03 04:41 PM

Steam Bending Plywood
 
Yes standard Baltic (actually Russian) birch is not even slightly water
resistant.

Kevin wrote:
The problem with the local 3mm baltic birch that I have been able to
find is that it only has interior grade glue.... which I don't think
will hold up.

Kevin


"Trent Hink" wrote in message ...
Are you sure you can't get 3mm baltic birch ply locally?
It seems to be very popular for making drawer bottoms. Cheap and strong too.
I think 3mm should be flexible enough to cold mould the way you want.


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com


Backyard Renegade December 26th 03 10:15 PM

Steam Bending Plywood
 
Glenn Ashmore wrote in message news:DDZGb.11259$JD6.7487@lakeread04...
Yes standard Baltic (actually Russian) birch is not even slightly water
resistant.


Sure is nice for making scale models though
Scotty


Kevin wrote:
The problem with the local 3mm baltic birch that I have been able to
find is that it only has interior grade glue.... which I don't think
will hold up.

Kevin


"Trent Hink" wrote in message ...
Are you sure you can't get 3mm baltic birch ply locally?
It seems to be very popular for making drawer bottoms. Cheap and strong too.
I think 3mm should be flexible enough to cold mould the way you want.


Trent Hink December 27th 03 05:48 PM

Steam Bending Plywood
 
It seems to hold up very well for these:
http://gallery.kiteforum.com/gallery/albup46
But I always thoroughly coat it with epoxy and sometimes vacuum bag a layer
of glass on as well. Note the tortured shape, from 3 layers 3mm laminated
with rocker and bottom concave.

Nice springy "pop" like a snowboard. At 180lbs with frequent jumps to around
15', I haven't been able to break one or seen any signs of rot yet, even the
ones where I ground through to to bare wood riding over sand and (sometimes)
rocks.

Then again this is not an application where the wood is submerged for much
more than a few hours at a time.



"Glenn Ashmore" wrote in message
news:DDZGb.11259$JD6.7487@lakeread04...
Yes standard Baltic (actually Russian) birch is not even slightly water
resistant.

Kevin wrote:
The problem with the local 3mm baltic birch that I have been able to
find is that it only has interior grade glue.... which I don't think
will hold up.

Kevin


"Trent Hink" wrote in message

...
Are you sure you can't get 3mm baltic birch ply locally?
It seems to be very popular for making drawer bottoms. Cheap and strong

too.
I think 3mm should be flexible enough to cold mould the way you want.


--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com




Kevin December 28th 03 05:13 PM

Steam Bending Plywood
 
Did so more searching and found sources localy for:

1- 3 Ply 3mm (1/8 inch) Italian Poplar called Bending Poplar

2- 3 Ply 2.7 mm meranti VC (What does the VC mean?)

3- 2 Ply 2.7 mm meranti

4- 3 Ply 2.7 mm meranti A-3 VC (I assume this is grading
information... somoene want to decode it for me?)

5- 3 Ply 3mm Obeche


Which would be my best option for my rounded driftboat transom, and
what are the various strenghts and weaknesses of the above listed
woods?

Thanks in advance,
Kevin

Kevin December 29th 03 07:05 PM

Steam Bending Plywood
 
Just got back from the supplier on the above mentioned ply and
discovered that it was all exterior glue.... looks like I will most
likely ored in the 1.5 mm finnish birch from an aircraft supply co. It
is rated finnish grade gl-11 anyone know if this is water proof?

Kevin

Kevin December 29th 03 07:07 PM

Steam Bending Plywood
 
make that finnish grade gl-2 on my previos post.

Kevin

Brian Whatcott December 29th 03 11:36 PM

Steam Bending Plywood
 
Aircraft rated ply is one step beyond marine rated: specifically, it
must have no voids and no patches in any ply, and be waterproof glue
laminated.

Brian W

On 29 Dec 2003 11:05:49 -0800, (Kevin) wrote:

Just got back from the supplier on the above mentioned ply and
discovered that it was all exterior glue.... looks like I will most
likely ored in the 1.5 mm finnish birch from an aircraft supply co. It
is rated finnish grade gl-11 anyone know if this is water proof?

Kevin



Kevin December 30th 03 03:45 AM

Steam Bending Plywood
 
My brain must not be fully in gear today.....
the problem with the long list of ply that I found is that it was all
interior grade glue... not exterior as I stated above (guess the
mental clutch is slipping).

So now I think I will either do a layer of 1.5mm gl-2 finnish birch
followed by 6mm of chopped glass and resin, topped by another 1.5mm
birch ply (for 9mm of material) or 4 layers of the birch sandwiched
out with glass & epoxy to the desired 9mm.

Which of the above techniques will be stronger?

The birch is sold in 4'x4' sheets at around $24.00 a sheet plus
shipping (about $10.00). I am trying to also decide which will be more
cost effective as I haven't decided wich is more expensive, an extra
sheet of birch or the epoxy and glass needed to build a 6mm inner
core.

Any thoughts on which technique is more cost effective?

As for bending:

I will soak the birch in a very hot bath, throw in some amonia (into
the hot bath), and spot spray with water & heat it with a flat iron as
needed while applying it (a technique I saw described in one of the
model airplane building groups where the guy said he wrapped 6 inches
1.5mm around a pencil, in a very tight spiral).


Thanks,
Kevin

Brian Whatcott December 30th 03 02:30 PM

Steam Bending Plywood
 
Beam strength in bending is determined by the strength of the layers
in the outside quarters. Glass will be cheaper stronger and more
durable than the ply. It's heavier too.....

If you use use ammonia, the heat and flat iron won't be necessary.

Brian W

On 29 Dec 2003 19:45:58 -0800, (Kevin) wrote:

My brain must not be fully in gear today.....
the problem with the long list of ply that I found is that it was all
interior grade glue... not exterior as I stated above (guess the
mental clutch is slipping).

So now I think I will either do a layer of 1.5mm gl-2 finnish birch
followed by 6mm of chopped glass and resin, topped by another 1.5mm
birch ply (for 9mm of material) or 4 layers of the birch sandwiched
out with glass & epoxy to the desired 9mm.

Which of the above techniques will be stronger?

The birch is sold in 4'x4' sheets at around $24.00 a sheet plus
shipping (about $10.00). I am trying to also decide which will be more
cost effective as I haven't decided wich is more expensive, an extra
sheet of birch or the epoxy and glass needed to build a 6mm inner
core.

Any thoughts on which technique is more cost effective?

As for bending:

I will soak the birch in a very hot bath, throw in some amonia (into
the hot bath), and spot spray with water & heat it with a flat iron as
needed while applying it (a technique I saw described in one of the
model airplane building groups where the guy said he wrapped 6 inches
1.5mm around a pencil, in a very tight spiral).


Thanks,
Kevin



Dan Thomas January 2nd 04 03:50 AM

Steam Bending Plywood
 
(Kevin) wrote in message . com...

As for bending:

I will soak the birch in a very hot bath, throw in some amonia (into
the hot bath), and spot spray with water & heat it with a flat iron as
needed while applying it (a technique I saw described in one of the
model airplane building groups where the guy said he wrapped 6 inches
1.5mm around a pencil, in a very tight spiral).


Thanks,
Kevin

That was me. I had used the water spray/flatiron technique
to bend 1.5 mm aircraft birch ply around the leading edges of a wing
(a real airplane) where the radius was as low as an inch or so. I did
the pencil thing just to see how tight it would bend without breaking.
The ply will bend more easily across the grain using this technique,
since the outer plies are easily penetrated with the steam and will
deform well, while the inner ply is still somewhat dry and stiff and
works better parallel to the bend.
Don't use your wife's good iron. The resins from the wood will
stain it and she will get steamed up, too.

Dan

Kevin January 13th 04 03:16 PM

Steam Bending Plywood
 
Well.......
I bent and glued in the first layer of the 1.5mm finnish birch. Didn't
even have to steam it, just bent it around my buck. Today I am going
to do a couple layers of chopped glass mat, and maybe the outer skin.
I did test a chunk of the birch, submersing it in hot water. VERY
flexible, I bent it to about a 2 inch radius.

Cut the birch to shape using a utility knife. Was afraid that a saw
would have ripped it to pieces.

Kevin


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