Replies

1. 
   saschafer | Oct 08, 2007 06:54pm | #1

   First verify that your jointer's outfeed table is properly aligned. Take two boards that are a little longer than the length of the infeed table,  and joint their edges. Put the edges together and verify that they meet perfectly, without gaps at the center or the ends.

   Assuming your jointer is aligned: If a board is significantly bowed, and it's longer than the infeed table, it's best to first take out some of the bow by trimming the concave side surface at both ends. With the board concave side down, and using absolute minimum downward pressure on the infeed table (but normal pressure on the outfeed table), take a couple of light passes from one end, stopping as soon as the board rises enough that it stops cutting. Now turn the board around and take a couple of passes from the other end. Keep doing this, alternating ends, until the two flat sections meet in the middle.

   The above assumes that the bow is more or less uniform along the length of the board. If it's all concentrated at one end, then you have to work more on that end, of course.

   You have to work kind of like a stone sculptor: You have to sight along the edge of the board and mentally picture where that perfectly straight and true board you're looking for lies within the existing solid mass. If the board is really bowed, it may not be possible to get a flat board of sufficient thickness out of it. In that case, you have no choice but to look for another board, and save that one to be cut up into shorter pieces for another project.

   -Steve

    

   
   

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   Edited 10/8/2007 11:56 am ET by saschafer

2. 
   dherzig | Oct 08, 2007 07:28pm | #2

   I found that often when working with longer boards, particularly as the weight went up. I agree with your analysis that it is probably the weight of the board lifting the front end slightly as you start and the rear end slightly as you end. Now that I do the edge with a hand plane and the board in a vise I have no trouble. In the end it has turned out to be both faster and more satisfying that fiddling with in-board and out-board support to be just at the right height.

1. 
   WillGeorge | Oct 08, 2007 07:41pm | #3

   For what it is worth I agree. I have a old wooden 'jointer' that I only seem to use to 'correct' what my 'lectric' jointer or what 'I 'caused to happen.I would say if most of the 'sticks' are 'spot on', IT MUST BE ME!

1. 
   9619 | Oct 08, 2007 10:25pm | #4

   WG,
   Tell 'em to get an LN #8. No dust. No noise (expecially if you wax the bottom) and if you use a long shooting board, you will get the board flat! Ever since Norm got famous, we have had problems like this. :-)
   MelMeasure your output in smiles per board foot.