What causes wood to warp?
 

I've heard and seen that moisture causes different layers of wood to
expand at different rates, and thus the wood warps. But it seems that
if you dry the wood back out it doesn't un-warp, usually it cracks.

Here's why I wonder: I'm working on a small end table with my wife.
We bought a sheet of layered (don't know what you REAL wood workers
call it) oak and maple. We've gotten quite a ways into the project,
but this sheet, which is for the table top, has significant warp.
Probally close to 1/4" in some dimensions. So I'm wondering how to
unwarp that so we can secure it to the frame of the table.

The ideas we've had to date:
(1) Right now, so it doesn't warp more we have clamped it to scraps
of oak that run across.
(2) There's a lot of different clamps out there. Since the plan calls
for a railing to run around the edges of the top, we are thinking that
we can just clamp it to the railing. This may not take out all the
warp, but it will warp with the railing. Better in some ways. [The
railing will be pegged to the top. And the top will be pegged to the
frame. No visible fasteners, right?.]
(3) I've read quite a few post about planing the top. I'm not too
wild about that since, the top layer of oak isn't thick enough so that
all the warp could be planed out. I suppose we could plane the
bottom, but it seems like a bad idea to plane through the laminate
layers.


Suggestions? I'm very new to wood working, so I'm very open to ideas,
comments, and suggestions.

Emil

If it's a plywood top, then yes, just attach it down to the frame to
straighten it out. you could screw it in from the bottom (no one is
going to see the screws on the underside of a side table).

Oh boy. First off, NEVER plane plywood. It will do unspeakable things to
your planer and ruin the wood. The veneer (top layer of oak or maple) is
probably only about 1/32" thick anyway. Try cutting it roughly to the size
you need and placing it on a flat surface, then either clamping it down flat
with some straight boards or placing some weights on it and leave it alone
for a few days. If that doesn't work, report back, we'll get ya going in
another direction. --dave



wrote in message
news:1106335598.2c1afd9871a8b9944e7ced2b41464fd7@t eranews...
I've heard and seen that moisture causes different layers of wood to
expand at different rates, and thus the wood warps. But it seems that
if you dry the wood back out it doesn't un-warp, usually it cracks.

Here's why I wonder: I'm working on a small end table with my wife.
We bought a sheet of layered (don't know what you REAL wood workers
call it) oak and maple. We've gotten quite a ways into the project,
but this sheet, which is for the table top, has significant warp.
Probally close to 1/4" in some dimensions. So I'm wondering how to
unwarp that so we can secure it to the frame of the table.

The ideas we've had to date:
(1) Right now, so it doesn't warp more we have clamped it to scraps
of oak that run across.
(2) There's a lot of different clamps out there. Since the plan calls
for a railing to run around the edges of the top, we are thinking that
we can just clamp it to the railing. This may not take out all the
warp, but it will warp with the railing. Better in some ways. [The
railing will be pegged to the top. And the top will be pegged to the
frame. No visible fasteners, right?.]
(3) I've read quite a few post about planing the top. I'm not too
wild about that since, the top layer of oak isn't thick enough so that
all the warp could be planed out. I suppose we could plane the
bottom, but it seems like a bad idea to plane through the laminate
layers.


Suggestions? I'm very new to wood working, so I'm very open to ideas,
comments, and suggestions.

Emil

Thanks! That's the path we're on, and it seems to be working. Thanks
again!
Emil

On Fri, 21 Jan 2005 21:28:35 GMT, "Dave Jackson"
wrote:

Oh boy. First off, NEVER plane plywood. It will do unspeakable things to
your planer and ruin the wood. The veneer (top layer of oak or maple) is
probably only about 1/32" thick anyway. Try cutting it roughly to the size
you need and placing it on a flat surface, then either clamping it down flat
with some straight boards or placing some weights on it and leave it alone
for a few days. If that doesn't work, report back, we'll get ya going in
another direction. --dave



wrote in message
news:1106335598.2c1afd9871a8b9944e7ced2b41464fd7@ teranews...
I've heard and seen that moisture causes different layers of wood to
expand at different rates, and thus the wood warps. But it seems that
if you dry the wood back out it doesn't un-warp, usually it cracks.

Here's why I wonder: I'm working on a small end table with my wife.
We bought a sheet of layered (don't know what you REAL wood workers
call it) oak and maple. We've gotten quite a ways into the project,
but this sheet, which is for the table top, has significant warp.
Probally close to 1/4" in some dimensions. So I'm wondering how to
unwarp that so we can secure it to the frame of the table.

The ideas we've had to date:
(1) Right now, so it doesn't warp more we have clamped it to scraps
of oak that run across.
(2) There's a lot of different clamps out there. Since the plan calls
for a railing to run around the edges of the top, we are thinking that
we can just clamp it to the railing. This may not take out all the
warp, but it will warp with the railing. Better in some ways. [The
railing will be pegged to the top. And the top will be pegged to the
frame. No visible fasteners, right?.]
(3) I've read quite a few post about planing the top. I'm not too
wild about that since, the top layer of oak isn't thick enough so that
all the warp could be planed out. I suppose we could plane the
bottom, but it seems like a bad idea to plane through the laminate
layers.


Suggestions? I'm very new to wood working, so I'm very open to ideas,
comments, and suggestions.

Emil