Q: We have some 3-inch cherry squares that have end checks that may be as long as 4 inches. We used an end coating, but we still got these checks. I have attached a kiln schedule that our operator uses. What next?
A: End checks develop from rapid drying of the ends. However, with the end coating, the ends should be drying quite slowly - unless you didn't get the coating on soon enough. Once a check starts, it is darn near impossible to stop the checks from developing. Do you know the history of the lumber? Was it old when you end coated it? Look inside some of the end splits and see if there is any coating inside the check, indicating that the check was already there when the coating was applied.
Next, the Dry Kiln Operator's Manual (U.S. Dept. of Agriculture Handbook No. 188) indicates that the correct schedule for 3-inch cherry squares begins with a 5 F depression, but your schedule uses an initial setting of 10 F depression. Your schedule will dry twice as fast as recommended! Try the correct schedule and your end checking will disappear.
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