How to Trim Warped Boards Straight

[William]

I have a number of two year old 8"x8' red oak planks that were rough-cut straight but have warped laterally about 4 inches. There's no cupping, just bent like a banana. The oak tree this wood came from was leaning over a boathouse on the river and the owner had the tree cut down. The warping is apparently due to unrelieved lenghtwise stress in the wood that came out during the drying.

My question is how can I trim the boards lengthwise straight to get the first side straight? If I put the convex side against the fence on a table saw, there'll be only one point of contact which will cause the board to wobble. If I put the concave side against the fence, the two points of contact will be constantly changing as the trailing curved part of the board comes in contact with the fence (the distance between the curved inside edge of the board and the fence will be constantly changing).

The only thing I can think of is to snap a chalk line along one side and hand feed the plank through a bandsaw, but that would still not give me a true flush side.

Any help would be appreciated.

William

[Juergen Hannappel]

[...]

Attach somehow to a straight board/post, and run that post against the tablesaw fence. This way you have a straight side to run against the fence.

[Doug Miller]

Correct diagnosis.

The best use for this wood is in a fireplace or wood stove (as fuel, not as trim around it). No matter what method you use for making straight boards from this lumber, there will still be internal stresses that will be partially relieved by removal of some wood, and the boards will crook again. And again. Further, if you do manage to get more-or-less straight boards out of these, the grain won't be parallel to the edges either (which gives an undesirable appearance).

This tree should never have been sawn for lumber. It should have been cut into

18" lengths and quartered with an axe.

If you're determined to use it as lumber anyway, read on...

Correct on all counts. The latter approach is the typical one when dealing with slightly crooked stock, but it won't work for a crook of the magnitude you're describing.

Close enough, though, that you can use that side as a reference surface against the tablesaw fence or on a jointer. Or you can bandsaw it as you describe, and then handplane it straight.

If you don't need the full 8' of length in a single board, cut them shorter first and then straighten them using any of the methods you suggested above. That will substantially increase the yield, and substantially reduce the magnitude of later changes in shape.

I still think this wood is best off in a fireplace, though.

-- Doug Miller (alphageek at milmac dot com)

How come we choose from just two people to run for president and 50 for Miss America?

[stoutman]

Check out the Joint'R Clamp.

Woodcraft sells em Product number: 15J50

[John Grossbohlin]

I'd be inclined to cut it into shorter lengths and straighten an edge on the jointer. It's nice to have 8' lengths but with tension wood it is likely to move around a lot indefinitely. Cut into shorter lengths and used for smaller projects would likely yield better results.

On the other hand, if you are determined to use the 8' lengths and have a 6" or 8" jointer, do as you suggest, then rip the opposite edge on the table saw. At this point don't worry if both edges are perfect... you're just trying to get it straight enough and narrow enough for the next steps. The next step is to face joint one side, thickness plane, then edge joint one edge, then rip the other edge on the table saw and finish the sawn edge by taking a light pass on the jointer. Now that it is straight, flat, and dimensioned, glue it to a 1/8" or 1/4" steel plate with epoxy to keep it that way. ;-) Seriously, it is unlikely to stay that way at 8'...

John

[William]

That's what I decided to do. That way the curvature is minimal on each section. I wouldn't have used this wood as you and Doug Miller mentioned except that it's a small project "for my eyes only" and the wood is what's available.

I do like overkill. A 1/4" steel plate behind each piece is a nice touch. After factoring in the cost of buying the steel and having it cut to size, I could probably buy 1000 board feet of straight red oak for the same price. But I do like the way you think! :)

Thanks to all for your replies.

Regards,

William

[Andy Dingley]

Why not use it for chair backs ? Saves steaming it to shape.

If "knees" are good enough for boatbuilding, why not chairs ?

-- What ? Me ? Evil Dictator of Iraq ? Nah mate, I'm just a Hobbit, honest