Straightening old wood for re-use help needed

[Aaron Rosenthal]

Background: I was the recipient of swack of Oak by one of my benefactors; it's all machined, and most the pieces are parts of pews. 2 3/4" wide, 8' long 5/8" thick, bullnozed one edge.
They're the vertical pieces that retain your prayer books from falling off the pews, so they naturally, they were never allowed to bow because of the screws each edge and in the middle.
I'd like to use them in 4' lengths, but they are bowed.
What I tried after research, was steaming the wood on the concave side (after cutting them to length) using an iron and damp towel; I put a weight on it as it "dried" but after a weekend the bow has returned.
I really do need to use wood that's straight for my project - and I'd really like to use reclaimed - I have it, and lots more.
Those of you who have bent wood, what can I do to reclaim this Oak?

[Lee Schierer]

You should take a look at this link that was provided in a different thread regarding how to straighten warped wood.

[Maurice Mcmurry]

I have experimented with dry heat (heat gun) and with steaming the entire piece then forcing it beyond straight and flat and holding it there. If steam does not do the trick I sometimes boil the wood. Boiling will make some wood species ugly and unusable for a natural or stained finished product. I have also tried splitting warped wood and reversing the two halves before glueing them back together. It is an uphill battle and the results are often not very good. The article from Lee is excellent and shows what forces are involved in a very good way.

[Mel Fulks]

Work on the convex side. That makes it worse ! But wait! The cells get mashed together, like too many fat people in an elevator.
Then the cells can’t recover, as they dry they they shrink (the cells …not the fat people). Now skinny, they “pull together “ straightening
the board. It’s called “compression ring-set” .

[Mel Fulks]

I’m sorry. Think I botched it . That method is more for warped stuff.

[Dan Hahr]

Oak is cheap. Buy some straight stock. Use the warped stuff for projects that you don't need straight wood for.
Dan

[Bradley Gray]

Oak is cheap. Buy some straight stock. Use the warped stuff for projects that you don't need straight wood for.
Dan

This. Use the warped wood to make butcher block for another project.