Over the weekend I resawed some 12″ cherry boards so I could bookmatch them and subsequently use them as panels in my armoire project. When I finished the resaw operation and planing the boards to remove saw marks, the finished pieces were roughly 5/16 of an inch thick.
And they cupped something fierce. Probably a half-an-inch from a side to the center of the board. One of them even developed a bit of a twist.
I wasn’t completely surprised, nor was I too concerned. My first attempt to flatten the boards was to set them out in the sun cupped side down. My thought was the Sun shining on the longer side would dry the board out and flatten it. Alas, that didn’t work very well.
When the humidity moved in today, I decided to try the opposite tact. I laid all the boards cupped side up on my workbench in an attempt to expose the shorter side to the humidity so it would expand. Wouldn’t you know it, the gambit worked. In less than a day no less. The boards are flat as a pancake now.
Chances are the technique wouldn’t work as well on thicker boards, but definitely something to keep in mind for future applications.