Where do you dry your lumber?

[Kyle]

electric.. gas is too expensive and steam generated by wood waste is highly inefficient except with large boiler operations. vacuum way too expensive.

DH uses an industrial HVAC unit and a heater coild system for the >135 temps..

[walnutjerry]

Originally Posted by Kyle

your buddy in drying wood is time. Too fast and you have honeycomb or severe checking and other defects.


One reason a real kiln is good is insects..powder post, green ash borer and their ilk can spring up years later if the drying temps do not get above 135 degrees for a minimum of 24 hours. The key word here is 135 degrees SUSTAINED which is impossible without an artifical means.

That is good information Kyle. Not many people woodworking as a hobby realize kiln drying does more than reduce the moisture content. I have been told that kiln drying also stress relieves the wood. Are you in agreement with that?

Jerry

[Gofor]

Originally Posted by walnutjerry

T I have been told that kiln drying also stress relieves the wood. Are you in agreement with that?
Jerry

I bought some 8/4 x 8"w white oak several weeks ago. I do not know if it was kiln dried or air dried, but the mc is too low to register on my HF moisture meter (less than 7% +/-1%). I cross- cut the nine foot boards in half today. One split at the cut along the rays in 6 places (I can't tell the depth yet, but the widest split is 1/32" x 2" long). The funny thing was that the split only occurred on one side of the cut, which tells me the stress is further down that piece. The boards are flat sawn but relatively close to the center of the heart. The mc was measured in the center of the board at the cut and I still could not get a reading meaniing it is below the 7%. Guess wood is going to do what it wants, regardless of how we try to prevent it.
Another observation today. I stacked/stickered the 8/4 I got from Jeff Sunday. Outside surface/end mc read about 18%. I cut off the split ends and sealed them. Mc at the center of the cut was 25%. Lesson for me learned: If you have a cheap mc meter like mine, you can't get deep enough into the board to get a good reading without making a cut.

JMTCW
Go

[Kyle]

Originally Posted by walnutjerry

That is good information Kyle. Not many people woodworking as a hobby realize kiln drying does more than reduce the moisture content. I have been told that kiln drying also stress relieves the wood. Are you in agreement with that?

Jerry

absolutely.. Stress relief is generally performed at the END of the drying cycle.you equilibrate the load with and over abundance of steam and turn off the vents. This will eliminate dry and wet pockets remaining and supposedly equilibrate the wood to all one moisture content.

Stress is a combination of the way trees grow and how the tree is sawn as well as how it is dried. I prefer to air dry first to allow the wood to move the way it wants and cull out the pieces that have grain splits, bow, twist or other malformation before kiln drying.