Hand Tools

Subject:
All twist doesn't have to be removed *PIC*
Response To:
Removing twist ()

Bill Tindall, E.Tn.
I find woodworkers fretting over flatness more than necessary. I don't deny that working flat lumber is easier but in practical woodworking we deal with unflat lumber, or reject a lot of lumber that isn't perfect.

There are a few occasions that require dead flat, an unframed door for example. If it is not flat it won't align in the opening and there is no way of pulling it flat in the assembly. If your board is destined for this application choose another.

At the other extreme there are boards and panels that are constrained by more or less stout framing or joinery. Those that are disturbed by radical woodworking practices should read no further. This table provides an extreme example of dealing with a very not flat board.

By cross cutting it in the middle and folding it back on itself the board that made up this top yielded a stunning, near book match pattern, of curly walnut. I was highly motivated to utilize this board for the top. The problem was that one end curled up, a lot. I carefully prepared the glue joint, laid the two boards on some stout bar clamps and forced the curved end flat against the clamps with jacks forced between the panel and the shop ceiling. After the glue was cured the top was unclamped and the corner of one end curled up about 3/4".

The top was to be fastened to a frame that defined a flat plane. I fastened the not flat top to the frame with table top fasteners, leaving the curled up corner largely curled up. Over the course of a month I tightened the screws holding the top to the frame. Eventually it pulled flat against the frame. That was 10+ years ago. Over time the stress of pulling the corner flat dissipated.

The point of this tale is that in many applications a board cupped or twisted will be constrained by framing or joinery to become flat. Not flat makes doing dovetails more difficult but I deal with this problem often. Most every panel I ever put in a frame and panel assembly was more or less cupped before installing in the frame (which pulled it flat enough and kept it so) It is just part of learning to do practical woodworking. Again, it is easier to work flat lumber when you can, but learning to utilize unflat lumber should be part of gaining experience in building stuff.

So, what is this board to be used for, and can you deal with a bit of twist in this application?

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