Does anyone have trouble with degrade on oak when drying with a dehumidifier kiln? I air dry first but I seem to have better results from green. It's that last drying from 16%-10% that seems to create problems. Has anyone tried adding water in the kiln at the end of drying to get good results?
From Professor Gene Wengert, forum technical advisor:
Except for cup, all other degrade is the result of improper drying at much higher MCs... above 45% MC for oak. Because the wood is so strong at 16% MC, it is virtually impossible to initiate new checking or honeycomb degrade. Further, staining is also a high MC event. Because air drying is uncontrolled (drying rates can be too fast or too slow, and rewetting can occur from rain), air drying can cause a lot of degrade. That is why shed drying is often preferred for oak.
Adding water to partially dried lumber can create a tremendous amount of interior checking as well as some surface stain.