Question
I was given three beautiful 16' cherry logs and had them sawed to 1-1/8". I stickered it and covered with a tarp for 6 weeks. I got it to the kiln and the MC was 16%-18%. The gentleman that owned the kiln said he would have it for six weeks. He called me after three weeks and said it was ready and the MC was 6%. I got it home and stacked it up outside for two days before I got it inside. When I was bringing it in, I noticed some pieces were twisted. Just thought it was pieces that were on top in the kiln. I ended up with 5 pieces out of 400 bd. ft. that were flat. I called him and told him what happened and he told me that he never had this happen and didn't know what to do about it.
Forum Responses
(Sawing and Drying Forum)
From contributor M:
Black cherry will warp if it is not heavily weighted. I lost a 42" diameter log this way. I cut it into 2.5" thick table top slabs. It warped badly as it was stickered and waiting for the kiln to free up, and I did not weight it down. Lost the whole log. I just pulled some 8/4 thick cherry mantel stock out of the kiln. One row curled up about 4-5 inches about two feet from one end. The rows above this point were not as long; this meant the weights on this pack were not bearing down on this last two feet. Lesson learned; weight cherry heavily. What most likely happened is, your stock went on the top of the pack and was not weighted.
By the way, no one was ever able to offer an acceptable explanation, and in fact, most responses were something like "aw shucks, cherry is so easy to dry!"
As mentioned, crooked logs will produce warp-prone lumber no matter how sawn. The technical explanation for the warp is that the angle or slope of the grain was not parallel to the faces of the lumber.
Knotty wood also warps more, as you do not have the SOG parallel. Note: Slow drying will also make more warp, so when you covered the load with a tarp, you may have slowed drying too much.
