As with the example of cupping, when you decide to fix a specific problem of wood distortion, it should be with a goal in mind. In this example, the goal is to harvest a specific part from a board that is warped.
It only makes sense that if you have to straighten 18 lineal inches, the task will be easier and waste less material than removing material to straighten 36 lineal inches. For that reason, the evaluation phase of this process is best done with specific parts in mind.
The limitation to producing useable parts from a warped board is the thickness of the wood required to make a specific part. The full dimension of the part must exist within the volume of the wood you are machining.
If, by reason of the wood's curvature over its length, you need to remove so much material that the board's thickness is less than that of the part, you need to find another piece of wood or move to a different segment of the warped board you are looking at. The curvature of a warp will not be uniform down its length, so you might be able to produce a specific part from one section of the board, but not another.
For all of these reasons, the first step in dealing with a warped board is evaluation. When you have determined which segment of the overall board can produce the part you want, cut that section out. As the next step is face jointing, do not cut out a piece that is too small to safely face joint ... 16" is a minimum safe length.
After that, the process is very similar to that described in "Five Steps to Correcting Cupping.•bCrLf The only caveat is that you'll need to check the board for twist after you face joint. Do this with a pair of shop-made winding sticks (photo 3 of this "red•bCrLf sequence). Proceed through the steps and you will end up with a flat, parallel and square piece of wood from a warped source.
Dealing with twisted boards is essentially the same as the process of dealing with warped stock. The key difference is how you address the face jointing. See the sidebar at right.
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| 1. Evaluate segments of the warped board to access whether you can get your desired part out of the piece. A template of the part (on the saw table) is very useful during this process. |
2. After you cut out the piece of stock appropriate for your part, face joint the piece. For safety's sake, the piece should be at least 16" long. It is better to waste a bit of wood than get hurt. |
3. Don't assume that your stock is out of twist just because you face jointed it. Check your piece with a pair of winding sticks. A minute of patience is worth an hour of power. |
4. Plane the stock flat with parallel faces. The length of the piece is important here, too. |
5. With the stock flat and the faces parallel to each other, joint the edges square. The piece is now ready to be formed - from warped board to useful stock in five simple steps. |
| Click an Image Above to Enlarge |