Q: We are experiencing splitting of red oak panels that are glued from narrow strips. What is the cause? Our incoming lumber is 10 to 11 percent MC and our plant is held at 47 to 52 percent RH.
A: Are you in North America? If so, the interior climate in most homes and offices is around 30 percent RH in the wintertime; the wood will be trying to achieve 6 percent MC on the average. It is prudent to run the manufacturing plant at 35 percent RH so that changes between manufacturing and the in-use environment are minimal. Further, the lumber should arrive at the manufacturing plant at the same moisture as will be achieved in-use in the wintertime, that is, 6 to 7 percent MC. Failure to follow these suggestions very closely will lead to checking, open glue joints, warping and other defects related to moisture change. The Wood Component Manufacturers Assn. has a good video about cures for moisture problems in wood.
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