Just curious if you drying experts could tell me if this is a common occurrence. I buy a lot of hardwood, especially quartersawn white oak, and 90 percent of the time the wood I get is case-hardened. This is very aggravating.
Also, white oak is a real tough wood to dry properly. I would think that air drying for 6-plus months, then a slow (assuming 4/4 lumber), steam injected, kiln dry to the final 6 to 8 percent moisture content would lessen the chance of case hardening.
Have you thought about buying the lumber green and air drying it yourself? The kilns you are buying from may not be air drying the lumber long enough before starting the kiln drying. And, to maximize their throughput, they may be using a kiln schedule that is to aggressive for white oak.