Q: We have just pulled some 4/4 ash lumber out of our storage shed that has been there at least a year. Guess what? The moisture content is no longer 7 percent MC but is pushing 10 percent MC. How can we redry this wood? Do we also have to relieve stresses (casehardening)?
A: You can redry the wood easily. Because it has been such a long time, I suspect that the added moisture is throughout the load of lumber and even the core MC is higher than desired. Therefore, you will need to restack the lumber. Then heat the kiln to 130F and set the humidity to an EMC that is halfway between the present MC and the desired final MC; in your case, halfway between 10 and 7 percent is 8.5 percent EMC. After about 24 hours, go to 140F and 5 percent EMC. You can then check the MC daily, raising the temperature 10F every day up to 160F and keeping 5 percent EMC. It will not be necessary to recondition, but check the stress to be sure.
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