On 4/11/2016 9:22 AM, DerbyDad03 wrote:
On Monday, April 11, 2016 at 8:57:14 AM UTC-4, John McCoy wrote:
DerbyDad03 wrote in
:

3/8" on one drawer, 1/2" on the other.

So you're saying there's 1/8" of sag?

No, I'm saying there is 3/8" sag on one drawer and 1/2" sag on the other.

Based on a prior post
where I think you said the sides extend 1/2" below the groove.

I don't think I'd worry about 1/8" of sag.


I wouldn't either, but that's not what I have.

That is a lot of sag, but I don't see any mention that it interferes
with the operation of the drawers.

If it's not hurting anything, I'd leave it alone. It took many years to
develop, it will take many years to flatten without using lots of force
and risking cracking and placing other components under stress. If
anybody else even notices it, call it "character" and explain to them
how it proves originality and enhances value. It's OLD, it's supposed to
be wrinkled.

On Monday, April 11, 2016 at 8:47:58 AM UTC-5, wrote:

The hardwood brace/support also serves to strengthen
the drawer structure somewhat - joining the drawer-front
to the drawer back at the center.
All the other discussion about just reversing the drawer-bottom
curve, without adding bracing - seems like it might be temporary ?
John T.

Reshaping, only, is not always temporary, if the over correction is sufficient to maintain a flattened result.

I'd agree that extra support would assure further stability. A narrow metal angle iron type bracing, under neath, would help.

I think someone mentioned placing a cross piece/divider inside the drawers, to function similarly. A divider is a good idea, also, and probably wouldn't look unsightly, either.

Sonny

On 04/11/2016 8:59 AM, dpb wrote:
....

The alternative is, as also noted elsewhere and by others, use some
external stiffener either on bottom or inside the drawer--another ploy
in that regard that makes some more significant changes to the piece is
to add a middle divider so that you have another support in the middle
like the back. That, of course, changes the piece more but can be done
without terrible damage so can be (mostly) reversed but would leave signs.
....

BTW, presuming the bottom is still solid but just bowed, you can do the
divider trick w/o actually attaching it directly to the front so the
modification evidence is minimal if taken out. The bottom is
constrained by the groove at the edge and held in place by the brads at
the rear plus you can go thru the rear side so when the bottom is
brought up to the bottom of the divider it (the divider) can't go
anywhere; the bottom has to come up to it. That's for front-to-back;
side to side you've got grooves both ends.

For the one I recall specifically did for wife's shop I actually took
the bottom out, used a hand router plane and cut a stopped dado for the
divider in the front inside and pinned it to add some extra rigidity.
It was even wider than yours, though, 42" iirc...was a buffet-like
piece, not a dresser.

--

dpb wrote:
On 04/11/2016 1:34 PM, dadiOH wrote:
dpb wrote:
On 04/11/2016 9:07 AM, dadiOH wrote:
...

Which means that you have to get the bottom fully into the
grooves. Or, at least, far enough to remove the "belly". Once
there, a couple of screws through the bottom into the sides should take
care
of it.

The length of the arc for a 1/2" sag in the center for a chord
length of 36" is 36.0185" -- thus the movement on either end of the
bottom is only about 0.01". Not significant. There's no chance you can
prevent that kind of movement in wood w/ a mechanical fastener from
the side (besides the damage done to the piece in trying to do
that).

No, not from the side, through the side and bottom from the bottom
of the side; i,e, vertically, not horizontally.

Never work, DD's perfectly correct in that; it's the side of the
fastener that you're expecting to constrain less than 10-thou movement
with--ain't a'gonna' happen, wood simply isn't that rigid, plus, as he
says, it'll cobble up the drawer itself somethin' awful in the
attempt.

Wait! You mean that all those jillions of frame and panel doors are
useless???

DerbyDad03 wrote:
On Monday, April 11, 2016 at 10:07:29 AM UTC-4, dadiOH wrote:

The question is, why did it bow in the first place? I can only think
of two reasons...

1. The grooves are wider than the bottom is thick. If that is the
case, pushing the bottom flat and gluing in a few small wedges into
the too wide groove should fix it.


2. If the grooves are not wider than the bottom is thick then the
drawer sides have moved out of vertical and possibly parallel. Is
the distance between the sides exactly the same at both top and
bottom all along their length?

There are at least 2 more possibilities, probably a combination of
both. I list these in no particular order:

- Obviously, years of weight on a 36" x 18" piece of 1/4" wood (or
even plywood) could cause considerable warpage. I can't speak to the
contents
of the drawers over the years, but anything other more substantial
than
linens could certainly have warped the bottoms.

Quite true if the construction was such that bending could occur. If you
glue a 1/4 x 36 x 18 piece of ply across a couple of 2x4s then clamp down
the 2x4s and stand on the ply, do you think the ply will bend? I don't.

- The bottom side of the drawer bottoms are unfinished, the tops are
finished with what I assume is varnish. I can only assume (I'm no
expert by any means) that the raw bottom would have absorbed more
moisture over the years, resulting in swelling/uneven movement.

Also true but it doesn't take years, just a few days. Maybe even less in
the winter with the heated house resulting in much lower humidity.

I'm in the process of building an entry door. The glued up panels are 7/8"
thick. They were built 3-4 weeks ago during a rather warm, humid spell. It
turned cool again and I noticed a couple of days ago that the 26" wide
panels had bowed, probably 1/4" - 3/8" belly. No big deal, if they haven't
flattened themselves out when I get to assembling stuff I'll just dampen the
concave side.

Note that the panels would not have warped if the edges had been
constrained; split, maybe, but not warped.

Bottom line, and I know you'd agree if you saw the drawers, the
bottoms are bowed beyond the point where edge attachments are going
to flatten them.

Maybe so but whatever you do won't last unless you correct whatever caused
them to warp in the first place. If it were me, I'd just do the best I
could and forget it. A bit of belly in a dresser drawer isn't gong to hurt
anything; maybe even help if one keeps one's marble collection in it

On 04/11/2016 6:09 PM, dadiOH wrote:
....


Wait! You mean that all those jillions of frame and panel doors are
useless???

Huh?

--

DerbyDad03 wrote in news:1df6083d-1b73-47c2-993a-
:

On Monday, April 11, 2016 at 8:57:14 AM UTC-4, John McCoy wrote:
DerbyDad03 wrote in
:

3/8" on one drawer, 1/2" on the other.

So you're saying there's 1/8" of sag?

No, I'm saying there is 3/8" sag on one drawer and 1/2" sag on the other.

OK, think I mis-read your prior post to say you were measuring
up from the underside of the drawer.

I am surprised, with 1/2" of sag, that the bottom hasn't pulled
out of the grooves in the sides. If that bottom is solid wood,
which way does the grain run? Is it possible the wood has
expanded due to humidity, and can't fit without bowing?

John

On 04/11/2016 6:13 PM, dadiOH wrote:
....

glue a 1/4 x 36 x 18 piece of ply across a couple of 2x4s then clamp down
the 2x4s and stand on the ply, do you think the ply will bend? I don't.

Of _course_ it will; it doesn't have an infinite modulus of elasticity;
if it were 1/4" steel plate it would still bend; just not quite so much...

Let's see...from FPL Wood Handbook, for plywood

E -- 1.10-1.24x10E5 lb/sq-in

and for a rectangular solid beam the moment of inertia is bh^3/12 where
b=width, h=height so for the drawer that's

I=18*(1/4)^3/12 -- 18/(12*4*4*4) -- 3/(2*4*4*4) = 3/128 =0.02344 in^4

For a constrained beam at both ends, max deflection at midpoint is

ymax=Wl^3/192EI

For a 200 lb load that's

ymax=200*36^3/(192*1.1E6*0.023) = 1.88"

For comparison, E for steel ~27E6 so the deflection would be about 0.07"
instead.

....

Note that the panels would not have warped if the edges had been
constrained...

If you build a panel door that is fully and tightly constrained on all
sides with no expansion room, it'll fail sooner rather than later. Door
panels in exterior doors are _not_ fixed; they float.

--

On Monday, April 11, 2016 at 7:51:10 PM UTC-4, dpb wrote:
On 04/11/2016 6:13 PM, dadiOH wrote:
...

glue a 1/4 x 36 x 18 piece of ply across a couple of 2x4s then clamp down
the 2x4s and stand on the ply, do you think the ply will bend? I don't.

Of _course_ it will; it doesn't have an infinite modulus of elasticity;
if it were 1/4" steel plate it would still bend; just not quite so much...

Let's see...from FPL Wood Handbook, for plywood

E -- 1.10-1.24x10E5 lb/sq-in

and for a rectangular solid beam the moment of inertia is bh^3/12 where
b=width, h=height so for the drawer that's

I=18*(1/4)^3/12 -- 18/(12*4*4*4) -- 3/(2*4*4*4) = 3/128 =0.02344 in^4

For a constrained beam at both ends, max deflection at midpoint is

ymax=Wl^3/192EI

For a 200 lb load that's

ymax=200*36^3/(192*1.1E6*0.023) = 1.88"

For comparison, E for steel ~27E6 so the deflection would be about 0.07"
instead.

...

Note that the panels would not have warped if the edges had been
constrained...

If you build a panel door that is fully and tightly constrained on all
sides with no expansion room, it'll fail sooner rather than later. Door
panels in exterior doors are _not_ fixed; they float.

--

I wasn't going to mention the fact that dadiOH wants me to secure the bottom
on 3 sides. Aside from all the other reasons that fix won't work, securing the panel
on 3 sides is probably a bad idea too.

dpb wrote:


If you build a panel door that is fully and tightly constrained on all
sides with no expansion room, it'll fail sooner rather than later. Door
panels in exterior doors are _not_ fixed; they float.

Gee, I learn something new every day.

On 04/12/2016 5:55 AM, dadiOH wrote:
dpb wrote:


If you build a panel door that is fully and tightly constrained on all
sides with no expansion room, it'll fail sooner rather than later. Door
panels in exterior doors are _not_ fixed; they float.

Gee, I learn something new every day.

You're welcome...

OTOH, I don't know why you're now getting snippy; just responded to your
comments implying trying to keep a panel flat by constricting the edges...

But, suit yourself.

--

dpb wrote:
On 04/12/2016 5:55 AM, dadiOH wrote:
dpb wrote:


If you build a panel door that is fully and tightly constrained on
all sides with no expansion room, it'll fail sooner rather than
later. Door panels in exterior doors are _not_ fixed; they float.

Gee, I learn something new every day.

You're welcome...

OTOH, I don't know why you're now getting snippy; just responded to
your comments implying trying to keep a panel flat by constricting
the edges...
But, suit yourself.

I wasn't trying to be snippy. If I was trying to be snippy, I would have
asked, "Float in what?" or "So I can't glue in a plywood bottom?".

And I don't think restraining the edges keeps a panel flat. Restraining the
top and bottom of the FACES at the edges, yes; edges themselves, no.

On 04/11/2016 6:50 PM, dpb wrote:
....

For a constrained beam at both ends, max deflection at midpoint is

ymax=Wl^3/192EI
....

BTW, just for comparison, if the ends were free instead of constrained
from rotation as was postulated, the maximum deflection is

ymax=Wl^3/48EI

Same form, just the constant turns out different. The deflection would
be 4X that of the constrained case (192/48--4).

--

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

On 4/12/2016 10:46 PM, Martin Eastburn wrote:
When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

That is very often lumber core, not plywood.



Your requirements of this or that or orientation doesn't hold water.

Actually I think it does.


Apple ply is not the same as a fur or pine ply.

Apple ply is an American version of Baltic birch plywood. Hard wood
veneers through out and each is running 90 degrees to the next.



Having a solid core is strong. The ply's on the outside is dressing.

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

On Tue, 12 Apr 2016 22:46:45 -0500, Martin Eastburn
wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

I'd call that "veneer", not "plywood".

https://en.wikipedia.org/wiki/Plywood#History


"In 1797 Samuel Bentham applied for patents covering several
machines to produce veneers. In his patent applications, he
described the concept of laminating several layers of veneer with
glue to form a thicker piece – the first description of what we now
call plywood.[1] Samuel Bentham was a British naval engineer with
many shipbuilding inventions to his credit. Veneers at the time of
Bentham were flat sawn, rift sawn or quarter sawn; i.e. cut along
or across the log manually in different angles to the grain and
thus limited in width and length."

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

On 4/12/2016 10:46 PM, Martin Eastburn wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

On 4/13/2016 10:05 AM, Leon wrote:
That is very often lumber core, not plywood.

Yes, lumber core plywood. All sorts of plywood, lumber core, MDF core,
Particle board core, veneer core, combination core etc. etc.

Your requirements of this or that or orientation doesn't hold water.

Actually I think it does.

It might based on some old patents for making plywood, but the term
plywood today seems just a generic term for laminated wood, which has
been around forever, (3000 BC?)and the requirements pretty much seems to
be 2 or more pieces of wood glued together. You can fight all day over
definitions, but ply and wood used together indicates laminated wood,
thus Martin got it right, "takes two to ply"... I'm thinking like tissue
paper vs kleenx

I bought some oak veneer "plywood" once at Allegheny Plywood that had a
core of some unrecognizable stuff that looked like plaster. Still, it
was 2 sheets of wood glued to some non-wood product, and they called it,
and sold it, as "plywood".

--
Jack
Add Life to your Days not Days to your Life.
http://jbstein.com

On Tue, 12 Apr 2016 22:46:45 -0500, Martin Eastburn
wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

On 4/13/2016 10:16 AM, krw wrote:
I'd call that "veneer", not "plywood".

You'd be wrong, veneer is not plywood. Veneer becomes plywood when two
or more sheets of it are glued together, then it is called plywood, and
if 3 or more sheets of veneer are glued together, it is called veneer
core plywood, as opposed to lumber core plywood, for example.

--
Jack
Add Life to your Days not Days to your Life.
http://jbstein.com


https://en.wikipedia.org/wiki/Plywood#History


"In 1797 Samuel Bentham applied for patents covering several
machines to produce veneers. In his patent applications, he
described the concept of laminating several layers of veneer with
glue to form a thicker piece – the first description of what we now
call plywood.[1] Samuel Bentham was a British naval engineer with
many shipbuilding inventions to his credit. Veneers at the time of
Bentham were flat sawn, rift sawn or quarter sawn; i.e. cut along
or across the log manually in different angles to the grain and
thus limited in width and length."

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

Jack wrote in :


On Tue, 12 Apr 2016 22:46:45 -0500, Martin Eastburn
wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

On 4/13/2016 10:16 AM, krw wrote:
I'd call that "veneer", not "plywood".

You'd be wrong, veneer is not plywood. Veneer becomes plywood when two
or more sheets of it are glued together,

No. It becomes plywood if the veneers are glued cross-grain.
That's fundamental to the definition of plywood. If you don't
beleive that, go ask the APA.

John

John McCoy wrote:
Jack wrote in :


On Tue, 12 Apr 2016 22:46:45 -0500, Martin Eastburn
wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

On 4/13/2016 10:16 AM, krw wrote:
I'd call that "veneer", not "plywood".

You'd be wrong, veneer is not plywood. Veneer becomes plywood when two
or more sheets of it are glued together,

No. It becomes plywood if the veneers are glued cross-grain.
That's fundamental to the definition of plywood. If you don't
beleive that, go ask the APA.

John


Agreed and IIRC. Plywood always has an odd number of ply's.

On 04/14/2016 7:20 AM, Leon wrote:
John wrote:
....

No. It becomes plywood if the veneers are glued cross-grain.
That's fundamental to the definition of plywood. If you don't
beleive that, go ask the APA.

....

Agreed and IIRC. Plywood always has an odd number of ply's.

So what is lumber-core, then?

--

On 4/14/2016 8:57 AM, dpb wrote:
On 04/14/2016 7:20 AM, Leon wrote:
John wrote:
...

No. It becomes plywood if the veneers are glued cross-grain.
That's fundamental to the definition of plywood. If you don't
beleive that, go ask the APA.

...

Agreed and IIRC. Plywood always has an odd number of ply's.

So what is lumber-core, then?

--




It is a solid plank, made up of many edge glued pieces of solid wood
with typically a cross grained outer layer on both sides and then an
exterior veneer on both sides with grains running parallel to the inner
core.

Typically common plywood is made up of thin alternating grain direction
ply's/veneer sheets.

A common plywood trait is alternating plies which adds strength and
stability and why plywood is often a better material for large areas
where dimension stability is important. You do not see plywood with
grain running in different directions on opposite sides therefore it
always has an odd number of ply's.

On 4/14/2016 8:57 AM, dpb wrote:
On 04/14/2016 7:20 AM, Leon wrote:
John wrote:
...

No. It becomes plywood if the veneers are glued cross-grain.
That's fundamental to the definition of plywood. If you don't
beleive that, go ask the APA.

...

Agreed and IIRC. Plywood always has an odd number of ply's.

So what is lumber-core, then?

--





BTY stay safe in the next few days! Looks like rain and wind is in your
forecast.

On 04/14/2016 10:33 AM, Leon wrote:
On 4/14/2016 8:57 AM, dpb wrote:
On 04/14/2016 7:20 AM, Leon wrote:
John wrote:
...

No. It becomes plywood if the veneers are glued cross-grain.
That's fundamental to the definition of plywood. If you don't
beleive that, go ask the APA.

...

Agreed and IIRC. Plywood always has an odd number of ply's.

So what is lumber-core, then?
....

Snipped for brevity...Gee, no way one can put in _any_ levity, can ya'...

--

On 04/14/2016 10:34 AM, Leon wrote:
....

BTY stay safe in the next few days! Looks like rain and wind is in your
forecast.

We're hopin'...wind is always with us; rain, "not so much".

Just heard on the AgrTalk weather segment this morning they've
officially announced a La Nina watch which means likely end of the El
Nino cycle and typically puts us back into the dry slot again...we just
emerged this last year from five years of extreme drought so if that
comes come to pass it ain't lookin' good again for a while...so a real
soaking wet event would be a godsend first...

--

In article , says...

On 04/11/2016 9:07 AM, dadiOH wrote:
...

Which means that you have to get the bottom fully into the grooves. Or, at
least, far enough to remove the "belly". Once there, a couple of screws
through the bottom into the sides should take care of it.

The length of the arc for a 1/2" sag in the center for a chord length of
36" is 36.0185" -- thus the movement on either end of the bottom is only
about 0.01". Not significant. There's no chance you can prevent that
kind of movement in wood w/ a mechanical fastener from the side (besides
the damage done to the piece in trying to do that).

Is the drawer 36 inches deep or just 36 inches wide? If it's not 36
inches deep then the chord you have to work with is the front to back,
not the side to side.

The question is, why did it bow in the first place? I can only think of two
reasons...
...

The most probable reason it bowed was that it had too much weight stored
in the drawer for 100+/- year and it's simple relaxation over the
unsupported span. No different than setting the set of encyclopedias or
a 100-lb bust of Beethoven on a long, unsupported bookshelf and leaving
them there--over time the shelf _will_ sag unless it's far more than
just a 3/4" ordinary shelf. In this case, we don't know what was in the
dresser, but whatever it was was too much for a minimal initial design.
1/4" is not enough material for a 36" drawer for anything but the
lightest of loads.

On 04/14/2016 9:56 PM, J. Clarke wrote:
....


Is the drawer 36 inches deep or just 36 inches wide? If it's not 36
inches deep then the chord you have to work with is the front to back,
not the side to side.
....

It's bowed _both_ directions, the long-ways is the longest unsupported
length which is the 36" dimension. The one edge (front) is supported,
yes, but the remainder is poorly supported by the failed nails along the
rear. Look at the pictures to see the geometry.

--

On 04/14/2016 11:33 PM, dpb wrote:
On 04/14/2016 9:56 PM, J. Clarke wrote:
...


Is the drawer 36 inches deep or just 36 inches wide? If it's not 36
inches deep then the chord you have to work with is the front to back,
not the side to side.
...

It's bowed _both_ directions, the long-ways is the longest unsupported
length which is the 36" dimension. The one edge (front) is supported,
yes, but the remainder is poorly supported by the failed nails along the
rear. Look at the pictures to see the geometry.

Oh, if you're bothered treated it as a beam instead of plate, the point
is how little it takes to get what seems a big bow in the center in
relative movement of the ends. The plate solution is significantly more
complicated to show the same thing; not worth the bother for the purpose
here...

--

I know Leon. Baltic Burch is from the Soviet Union / aka Russia.
It is a high quality board.

Martin

On 4/13/2016 9:05 AM, Leon wrote:
On 4/12/2016 10:46 PM, Martin Eastburn wrote:
When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

That is very often lumber core, not plywood.



Your requirements of this or that or orientation doesn't hold water.

Actually I think it does.


Apple ply is not the same as a fur or pine ply.

Apple ply is an American version of Baltic birch plywood. Hard wood
veneers through out and each is running 90 degrees to the next.



Having a solid core is strong. The ply's on the outside is dressing.

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in
news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

Have you ever worked on a Desk top ? You have several layers of
Veneers. The whole thickness might be 1/16".

Martin

On 4/13/2016 9:16 AM, krw wrote:
On Tue, 12 Apr 2016 22:46:45 -0500, Martin Eastburn
wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

I'd call that "veneer", not "plywood".

https://en.wikipedia.org/wiki/Plywood#History


"In 1797 Samuel Bentham applied for patents covering several
machines to produce veneers. In his patent applications, he
described the concept of laminating several layers of veneer with
glue to form a thicker piece €“ the first description of what we now
call plywood.[1] Samuel Bentham was a British naval engineer with
many shipbuilding inventions to his credit. Veneers at the time of
Bentham were flat sawn, rift sawn or quarter sawn; i.e. cut along
or across the log manually in different angles to the grain and
thus limited in width and length."

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

On Sat, 16 Apr 2016 22:52:47 -0500, Martin Eastburn
wrote:

Have you ever worked on a Desk top ? You have several layers of
Veneers. The whole thickness might be 1/16".

OK, and your point is?


Martin

On 4/13/2016 9:16 AM, krw wrote:
On Tue, 12 Apr 2016 22:46:45 -0500, Martin Eastburn
wrote:

When you have solid board core and a layer on both side that is pretty
it is PLY. Takes 2 to Ply.

Your requirements of this or that or orientation doesn't hold water.

Apple ply is not the same as a fur or pine ply.

Having a solid core is strong. The ply's on the outside is dressing.

I'd call that "veneer", not "plywood".

https://en.wikipedia.org/wiki/Plywood#History


"In 1797 Samuel Bentham applied for patents covering several
machines to produce veneers. In his patent applications, he
described the concept of laminating several layers of veneer with
glue to form a thicker piece – the first description of what we now
call plywood.[1] Samuel Bentham was a British naval engineer with
many shipbuilding inventions to his credit. Veneers at the time of
Bentham were flat sawn, rift sawn or quarter sawn; i.e. cut along
or across the log manually in different angles to the grain and
thus limited in width and length."

You are making commercial product and saying PLY has requirements to be
ply.

I've used Plywood since 51 or 52. They made it in the back shop of the
hardware store. They bought vernier sheets and made their own using
their waterproof glue for all uses.

Martin


On 4/11/2016 7:50 AM, John McCoy wrote:
Martin Eastburn wrote in news:IiEOy.11705$__
:

Plywood is simply veneer over another surface.

Well, no, not really. To be plywood the layers have to have
the grain going crosswise (or, rarely, at 45 degree angles).
That is what gives plywood it's dimensional stability.

Granted there are modern day composites used for "plywood"
cores that don't have grain, but those didn't exist when the
first manufacturers started making plywood.

John

Martin Eastburn wrote:
I know Leon. Baltic Burch is from the Soviet Union / aka Russia.
It is a high quality board.

Martin

Well, actually a high quality plywood. :-).

On 04/14/2016 11:33 AM, dpb wrote:
On 04/14/2016 10:34 AM, Leon wrote:
...

BTY stay safe in the next few days! Looks like rain and wind is in your
forecast.

We're hopin'...wind is always with us; rain, "not so much".

Just heard on the AgrTalk weather segment this morning they've
officially announced a La Nina watch which means likely end of the El
Nino cycle and typically puts us back into the dry slot again...we just
emerged this last year from five years of extreme drought so if that
comes come to pass it ain't lookin' good again for a while...so a real
soaking wet event would be a godsend first...

Well, we got home yesterday evening after being in SE KS for a family
funeral...rained on us in varying intensity from not far west of Iola
until nearly home where a shower had just passed. Many areas had from
4" to nearly 7"; there was a total of only 0.45" in the gauge at the
house only. But, guess we have to be thankful for that, 20 miles on S
was even less. The heavy rains "trained" over the same narrow bands for
two days and we were, as seems so often the case, in the are the inflow
setup and were thus "dryslotted" with heavier rains on both sides of us
as near as ten miles or perhaps less...radio in town said they had
around an inch which isn't 10 mi away to airport which is the
measurement location I presume they were using...

But, it is at least something altho won't last long....was a little
severe weather around, but not much other than some localized flooding
in the really local areas that got it. I'd not mind takin' my chances,
frankly given as dry as we've been for the previous five...a few
waterholes in low spots would be a novel occurrence.

--