I've dried a couple of loads in our kiln, the first being western red alder, then figured big leaf maple, now I'm working on some black walnut. All about 800-1000 bf. The first two loads went as intended, took me about 5 weeks to dry the loads; but this walnut is not drying correctly. I built a nice kiln box and installed a Nyle200m dryer. Trying to do this right. The trees were gifted to me, then they cut them down; the trees were diseased and dying. There is ring shake at about the 1/2 to 2/3 point of the circumference, which is anywhere from 20-30". Some burling in the sapwood. When I sliced the wood, it smelled kind of like vinegar, turned grayish, then back to brown again. 7/4 and 12/4 slabs. Started out around 50%mc on the 7/4, about 70% on the 12/4. Once in the kiln, I started experiencing the wet bulb wick getting slimy and not conducting water well or at all; it would dry up and turn brown if I didn't retrim it every 2-3 days (used bottled water). Took 3 months to work the 7/4 down to 12%, the 12/4 only went to around 60-65%. Dried some apple on top of this stack for a friend, it went from 30% to 8% in about 3 weeks. Took the apple out, kept at the walnut. Still smells a little odd. Got some water from the wood early, but it seems I'm just drying the wet bulb water now. I like to dry by watching how much water I get and the duty time of the compressor; I adjust the wet bulb accordingly. For the most part if I adjusted the wet bulb 2 degrees either way the compressor would either run at all times or not at all; was not this way with the first two loads. So...will diseased wood not dry, or is it me not knowing what I'm doing? Any comments are welcome, I'll answer questions as best I can. Thanx.