warp board issue

[fred henkin]

I have a 6' walnut board (natural edge) that is about 1 1/4" thick. I cut it in half length wise and am planning to add maple boards to the center to make a table. My problem is that there is a slight warp in the board length wise. Any suggestions about how I might get that straightened out? I planed it down form 1 1/2" which helped a little.

[glenn bradley]

What method were you using? If you removed 1/4" of material and still have warp I would consider that way more than a slight warp. I think slight ends at around a 1/16" for me but YMMV. When face jointing a severely warped board and wanting to minimize the material removal I will place the board on the jointer, teeter totter it to see how much movement I have. Let's say I have one portion of the board 1/4" off the surface when teetered or tottered to one extreme or the other. I place a shim about half that amount (1/8" in this case) under the trailing corner and keep that shim trapped while making a pass.

This means I am feeding the board with one corner up in the air and one on the table while approaching the cutterhead. The low corner gets the bulk of the cut and the high corner gets none. Same is true for the trailing end. I use old business cards or scraps of cardboard for shims so that when they hit the cutter they just "vanish". Repeat with a slightly smaller shim. Usually by the third pass I have enough flat surface to skip the shims and joint until flat. Plane to thickness and vois-la.

[David Keast]

I have a 6' walnut board (natural edge) that is about 1 1/4" thick. I cut it in half length wise and am planning to add maple boards to the center to make a table. My problem is that there is a slight warp in the board length wise. Any suggestions about how I might get that straightened out? I planed it down form 1 1/2" which helped a little.

You say planed down, the usual term is jointed, does this mean you fed it through a thickness planer ? If so, the result is not surprising, try the process Glenn proposes on this thread. If you dont have a jointer, you can do the same thing by hand, it just takes longer !