Kiln Dried Walnut

[Don L Johnson]

It is my understanding that the big hard wood dristributors typically sell walnut that has been kilned dried with steam, in order to make the wood more "standardized" looking. That's probably not the right way to say it. My question is as follows: There's a saw mill just a couple of hundred miles away that kiln dries their walnut without any steaming. Would the difference in the two be substantial? I'll be making a corner cabinet reproduction, and I would really like the walnut to be at its best. Thanks,

[David DeCristoforo]

Walnut has a wide variety of colors which most of us appreciate as one of the things that makes it a beautiful and desirable wood. But "most" people want to see a more consistent color. So most commercial kilns steam their walnut to accomplish this. It ends up being a fairly uniform purplish brown color. Unsteamed walnut has more variation with browns, reds some more amber tones and some black streaking as well.

[Quinn McCarthy]

Don,

The steam drying process halps to reduce the amount of sapwood that is visible through this process. If you want a more natural look go with the standard method. Some people really like seeing the sapwood streaks and other don't. You will have to decide for yourself what you want to see.

Hope that helps.

Quinn

[Lee Schierer]

There is a lot of discussion regarding the merits of each system; however, most of the color difference (purples and greens) in Walnut that is air dried disappears within a year or two after the project is finished and eventually (15+ years) the walnut will be tea colored instead of chocolate brown if it sees much daylight.

[Prashun Patel]

Don, you can do a lot with amber shellac or orange dye to warm up steamed walnut.

[David Keller NC]

"There's a saw mill just a couple of hundred miles away that kiln dries their walnut without any steaming. Would the difference in the two be substantial?"

Yes. As alluded to from several responders, the reason for steaming black walnut is to increase the yield from a given log. The chemicals that color walnut are mobile in the wood under conditions of high heat and water vapor, and the sapwood can generally be stained to closely match the hardwood by this process. But the result is a rather gray appearance, which is why some of us prize air-dried black walnut. In one sense, though, kiln drying without steam is about the same as the process with steam - it can case-harden the wood, and result in internal stresses that will crack, bow, warp or otherwise mess up boards re-sawn from a plank that was put into the kiln. This is true, of course, with other kiln-dried woods - it has a lot to do with the skill of the kiln operator and his patience (speed is not a friend to wood drying when it comes to case-hardening).

[Ron Bontz]

au natural for me. I wouldn't have it any other way. There's just something about those hues.:)

[Mike Parzych]

Kiln dried walnut can still retain its natural color IF it's air dried first - down to about 25%MC I believe.

There is NO comparison between steamed walnut and the real thing!

[Frank Drew]

I've used air- and kiln-dried walnut, but never steamed (I've always cut out sapwood). I agree with Lee that the purple grey/green color disappears under finish and with time; the older finished walnut I have is copper to copper/gold, depending on the light exposure.

Walnut's a beautiful wood but in my professional work I was rarely asked for it; around here its commercial popularity seems to have peaked in the late Seventies or early Eighties, right along about the time everyone started wanting cherry, which is a nice wood, of course, but doesn't have the visual interest of walnut. IMO.

[David Freed]

I agree with the comments about the differences in color between steamed and unsteamed, but the steaming process is not done in a kiln. Steam in a kiln is used to control heat and humidity in the drying process, and has nothing to do with coloring the wood. When walnut is steamed for color, it is a separate process before the lumber is put on sticks or put in a kiln. The lumber is put in the steam chamber dead-stacked right off the saw before it can start drying.

Here is a link to a detailed article about steaming walnut.
http://www.woodweb.com/cgi-bin/forums/comdry.pl?read=421015