I'm building a screen door for a Galveston beach house and decided to use white oak. Found some at a local sawmill - 4/4 S2S. It looked straight at the mill, but after sitting on my workbench in the shop overnight, 3 of the 4 boards were slightly bowed. I stickered it for a couple of weeks and nothing changed.
Today I decided to cut one of the rails from one of the bowed boards, thinking a shorter piece would be easy to straighten. Jointed one side flat, jointed one of the edges and took it to the planer to flatten the second side. After planing, the board is once again bowed slightly. Grrrrr! It is now 3/4" thick and I really don't want it any thinner than that because I plan to use mortise and tenon joinery to assemble the screen and don't want the tenons to be so thin that they are weak.
Any ideas as to why the board bowed after planing the second side? I'm a little frustrated.