Air dried vs. Kiln Dried ??????

[Tim Vice]

I see alot of turnings that are made out of raw wood(air dried). I have always been told that you must use kiln dried wood to keep the changing tempatures from cracking the wood.

In the kiln dried the microscopic water pockets in the wood are ruptured keeping the changing tempatures from affecting it as bad.

Any one ever had problem with thier air dried stuff cracking?

Any coments are appriciated.

[Reed Gray]

I prefer air dried wood to kill (kiln) dried wood. The cracking problem comes from the air dried wood not being entirely dry. Air dried wood needs to dry for at least 1 year per inch of thickness, and then for another 6 months just to be sure. The exact dryness is hard to determine just by touch and feel without a moisture meter. I have some black walnut slabs that are 2 inches thick. I left them outside, stickered and covered for a year, and they have been in my shop for a year and a half to finish drying. This gets the moisture content to around 10%. Kiln dried usually goes down to 6 to 8%, but when left in a shop will go back up to 8 to 10%, depending on relative humidity in the shop, and the area you live in. The biggest difference in the 2 is that when ripping a kd board on my table saw, I get dust. When ripping air dried wood, I end up with shavings. Much nicer to work with, almost like the difference between turning wet and dry wood.
robo hippy

[Jim Becker]

For certain species, such as walnut, I actually prefer air dried even for furniture.

For turning, I'll use wet right from the tree through KD, depending on what it is and what the source was. But in general most folks prefer to turn, at least for the rough stage, material with a bit of moisture in it...it turns easier that way. Turning to a uniform thin wall thickness generally (but not always...) keeps the cracking issues at bay. In fact, there are some woods, like locust, oak, pecan, hickory and osage orange that are bears to try and turn if they are dry. Hard as a rock!

[robert hainstock]

I have always prefered air dried, and have seen much kiln dried check, change shape, become propellers, Etc. the previous two posts nailed it pretty good. One thing I would add is that wood is always changing, can only change across the grain, and If you study the way realy old furniture was assembled, you will see that this fact was always takin into account when assembling the piece. :(:(:)
Bob

[Wally Wenzel]

I think that air dried walnut wood is much better looking than kiln dried, the colors are much brighter, when they kiln dry it they steam it to try and drive the color into the sap wood. Wally