Planing a board on the bot?

[myxpykalix]

I have a couple large cherry boards that are 21" wide x 8' long x 1.5" thick and the girl who put them in her kiln was too impatient and dried them too fast which caused alot of cracking on some boards and some warping on these.
When the other end is flat on the table this end sticks up about .75" by the time you get to the other end of the 8' board. I would like to keep them as wide as possible and i need a total of 28" for the top i'm building so what would be the best way to get these flat without losing a whole lot of thickness on the bot?

[barrowj]

I would shim both ends and get them equal distance off the spoilboard, that will minimize the amount you will lose. To put it another way, lift the opposite end .375 and shim it, then shim the other end which should now be .375. I would use hot glue to hold the shims and boards in place. I do this quite frequently.

Joe

[Keith Larrett]

Rip them into 3" wide strips. Plane them and then glue them back together. If you keep them in order you will hardly notice the joints.

[coryatjohn]

I use my SB as a fancy expensive planer all the time. I use a big bit (2.25") and take just a tiny slice off in each pass. That way, the amount of hold down required amounts to nothing. I shim like barrowj does but use scrap boards to box it in instead of hot glue. All you have to do is keep it from jiggling. Once you've got the top flat, flip it over and grind down the back without any shimming.

Another way I've fixed such things is to cut the board down the middle with my bandsaw, flip the pieces over and glue them together. The bow generally cancels out and the board is straight. Then just run it through the drum sander and all is well again. Using this method, the least amount of thickness is lost and the board ends up being just as strong as it was before slicing it.

[Joe Porter]

I would cut the board down to near the 28" you want for the table top and see how that looks....joe

[harryball]

I've faced this exact problem. I did much as Joe suggested, split the difference of the warp end to end. Once flat I used the "trued" side to run it through a planer then flip and plane the marks left from the 2.5" surfacing bit. From experience, shim it not just on the ends but in multiple places along the sides to reduce any chatter from vibration as it moves along. Take slow passes and be patient making multiple passes and you should be able to sneak up on flat fairly easily.

[knight_toolworks]

beat me too it it takes a lot of warp out the shorter the wood is.