I know that this is something from Woodworking 101, but I’d like to see if I have a handle on it. Indulge me if you will.
I bought a (approx.) 54” board of 4/4 Jatoba on e-bay not long ago. It had been sitting in the shop for 3 or 4 weeks, so I assumed it had acclimated to the shop. A few days prior to Christmas, I milled this piece to ½” thickness in anticipation of using it for my next box. I then left the newly milled and perfectly flat board untouched (Christmas, vacation, etc) for about 10 days in an unheated shop. Upon my return home, I went into the shop to check on this board. To my disappointment, it is now cupped beyond my ability to use it for its intended purpose. Let’s see if I have a good handle on what happened.
I assume that this board was not as dry as it should have been (I don’t own a moisture meter) and that upon re-sawing, the board continued to dry - albeit unevenly - and thus the cup.
Could it have had anything to do with my unheated shop? Was there anything I could have done differently to avoid this? I assume that had I finished my project right after it was milled (and prior to the cupping) that the wood would still have attempted to cup, and would have ruined any assembled project for which this board was used. Does all this sound about right?