Bowed elm plank. Can it be flattened?

[brianhr]

I have a piece of elm about 5ft long x 7in x 1 1/4in that has established a nice bow. Laid flat the centre is about 1 1/2 inches above the level of the bench.
Any suggestions how this could be flattened?

 

[Richard T]

I would do it the hard way if it were me (I have no other way) by scrubbing then flat planing. Elm is horrid to plane but a scrub doesn't care about grain changes.
How much of your 1 - 1/4" will you have left?

 

[brianhr]

I would have nothing left. The bottom of the bow is higher than the thickness of the plank.

 

[Paul Chapman]

As it's only 1 1/4" thick I don't think there's much you can do with it except rip it into thin strips and try to find a use for them. Lipping for MDF perhaps?

Cheers :wink:

Paul

 

[studders]

I 'improved' a long, wide, very bowed piece by leaving it suspended on bricks and with a heavy weight, I used an old car battery, in the middle for several weeks. I say improved because it didn't go flat but was a whole lot better than it started off at. Once flat enough I ripped it down the middle and flipped them around before re gluing. Might be worth a try?

 

[woodbloke]

Elm that's warped like this is going to be difficult to correct. I'd try and bow it the other way (using a coupla G cramps) for a few weeks and see what happens, but my guess is that once is taken on this sort of bow, it'll be very reluctant to go straight
The other thing to do would be to cut it into smaller bits (thus reducing the curve) and keep them as a matched set for something like a set of drawer fronts - Rob

 

[Tinbasher]

Cut it into shorter pieces and use them as pre stressed bookshelves !

 

[brianhr]

Many thanks to all. It seem as though the better solution is to use it in smaller pieces. There could also be a lot of elm lipped shelving around in the future.

Brian

 

[AndyT]

We're all assuming it's evenly dried, but you've told us nothing about how it was being stored when it took on its present shape.

If - for example - it was leaning against the wall of a garage, with bright sun shining on one side, then it's just possible that the sunny side has dried more than the back and so shrunk, causing the problem. So it would be worth turning it round and getting the back dried out the same.

Or maybe the long side has been allowed to get wet? Try wetting the other side, then letting it dry out evenly (ie put it horizontal, well supported, under cover but with good airflow all round.)

Whatever the case, if you don't need to use it immediately, it might be worth some experiments.

 

[RogerS]

I'd also go along with what the others have suggested.

One thing I have learnt is that if I rip down a board and the kerf starts to close/widen or the two pieces on either side start to diverge vertically then I'll go get another piece as I know that, no matter how much work I do on that board, it is going to move later on.