Squaring up long boards

[fred henkin]

I am working on 8' long pine boards that are 8/4 thick. They are rough and need to be squared up. I have a planer but need some guidance. I know that I can set the boards on another flat surface, shim them up then run them through the planers. What do you use for that flat surface taking into account how long the boards are. I would think that using any wood board would flex due to the length, defeating the purpose. ANy suggestions would be appreciated.

[Bradley Gray]

As long as you do the shimming with the support board sitting flat (on a flat surface) you should be good to go. The support board will sit on the bed of the planer and only the crown will be removed. Once you have a flat surface on the full length, flip to the other side.

[Mel Fulks]

Start by removing some wood from the convex side only. Many times that makes the piece straighten some. It seldom
(if ever) makes it get worse.
Convex side : meaning over whole length . Not across width