How to remove board warp, on thin stock

[dirk martin]

I've got some 1/4", 3/8", and 1/8" boards, about 24" long, and 6-10" wide.
cherry, ash, maple, red oak.
After resawing, many have warped somewhat.

Anyone got a trick to remove board warp?

[Dewey Torres]

Dirk,
Please post the intended application as it would help with the answer. Usually when folks re-saw, they are doing it for non-structural applications.

Example:

If these were going to be affixed to something flat and stable no problem...

[dirk martin]

Scroll sawing.

[Dewey Torres]

Ok... for my scroll work I usually plan to go thicker than the intended piece. I have a drum sander but if you leave room for a pass over the jointer and then to the plainer on the opposing side you will be flat every time. The problem with the jointer is that it won’t take stock that is very thin or small so it better to carefully plan your resawing if using that method. If you have a drum sander it will truly flatten, where as the planer will only transfer whatever the opposing side is... flat or otherwise. Be careful with thin stock through the plainer as well and make a carrier board, use double stick tape.

Secondly,
When you see wild grain on the long edges of a board it usually spells warp after resaw. Look for nice strait grain along the long edge and you will have better results.

[Chip Lindley]

Wood warps toward the side which dries fastest. (the side toward the air) Next batch, try clamping the boards together between flat cauls before they have the chance to bend.

Try moistening your warped boards well on the concave side and see them begin to flatten quickly. As they relax, clamp them between cauls for a time. Steaming is more radical but will certainly make the wood "plastic" so you may form it as you wish for a short time.

[dirk martin]

Dewey, maybe I wasn't clear, but the boards in question here, are already warped. I'm not trying to prevent warp, but instead trying to remove already existing warp in thin stock.

Chip, I'll try remoistening, on the concave side as you suggest, and see what happens. Thanks!