Furniture from Air-Dried Red Oak

If "air drying" is understood to include drying to equilibrium in a conditioned indoor space, then the result can be useable wood. May 27, 2008

Question
I have some 2" red oak planks that have been air-drying for about 1 year. The attached picture show 4 of these planks. One of my lumber customers wants to use some of this oak to construct some furniture (tables). Is it possible to build furniture from this oak without kiln drying? If so, what is the minimum time the lumber would have to dry indoors to be usable? I have now moved all the planks into my basement in a stickered pile to thaw them out.

Forum Response
(Sawing and Drying Forum)
From contributor A:
The moisture will be about 12 % MC, so it is too wet for indoor furniture. It will likely shrink about 1.5% MC as it dries and may also warp. You also could have powderpost beetles, so you need to heat the wood to kill them. They will not show up now, but will show up when the wood is warm for a few weeks or more. I would not suggest that this wood be used without kiln drying.


From contributor B:
2" thick might not even be down to 12% yet, it depends where it was stacked. If he is making rustic furniture where nothing has to be perfect 12% would be OK keeping in mind the wider boards might bend a little. I've built lots of furniture where it's only been up to 120 degrees and never had a bug come out yet.

From contributor B:
I've been building furniture with air dried wood for over 15 years now, and have never had a problem. I've always started by letting the wood stay outside until it's down below 20%. Then, it gets restacked inside my woodshed, where it stays until it's down to around 12%, which is about as low as it's going to get around my neck of the woods. I keep around 200 to 300 bf of each of the species I use most frequently (cherry, maple, poplar, and walnut) inside the shop, and I always make sure I have enough stock inside for 2 to 3 months before using it, so it reaches equilibrium with the shop. The MC gets down to around 8%, and I've never (knock on wood) had an issue.

If your customer needs to work the wood immediately, then those boards aren't ready. However, if he can wait a little while, and put them inside, they should be ready inside 6 months. American craftsmen have been building furniture out of air dried lumber for over 400 years. If you know what conditions are required, it's not a problem at all. And, the beautiful colors of walnut and cherry are much more brilliant when not introduced into a kiln environment.


From Professor Gene Wengert, technical advisor, Sawing and Drying Forum:

Although contributor C indicates that the wood is air dried, it is actually further dried at room temperatures, which is also the way lumber was dried by people 200 years ago. Today, we also air dry and then dry it in a kiln in a few weeks rather than wait for it to air dry at room temperature.

The phrase "air dried" has the connotation of 20% MC (+ or -), so it would not be fair to state that furniture was built with air-dried wood. If we redefine the phrase to mean that wood that has been air-dried will always be called air-dried, then even the kiln-dried wood used for the past century could be called air-dried wood.


From contributor D:
You've made a good point Doctor. Air drying, verses going through the extra steps of finishing the job in an indoor controlled environment, are two different things. Good results can be achieved by taking those extra steps. So saying air-dried, when it was dried in an outdoor stack, is not the same as saying air-dried when it was further dried indoors. Of course you have many times pointed out the benefits of additionally kiln drying to kill the bugs and set the pitch. It makes me wonder how our ancestors managed to make furniture that didn't always succumb to powderpost beetles.

From contributor B:
Doc, I'm sorry for the confusion in terminology. I guess, in a way, I'm using the dry conditions in my shop, which are kept that way with dehumidifiers in the summer months, as "the kiln" to finish off the wood. The only difference being that I'm not getting it done in 5 to 10 days.

I began working with my own sawn lumber as an experiment, because I was having difficulty finding consistent quality kiln dried lumber in the Chicagoland area. There are many, many suppliers around here, but you might (or might not!!) be surprised at how many times I'd resaw a 12/4 slab for bookmatched doors, only to find out I have some real expensive firewood. I now always make sure I stay ahead of my wood consumption rate by continually milling logs of the hardwood I use the most. That way, I rarely find myself needing to pay a visit to the hardwood store, unless it's something I don't use a lot.
Thanks for all your information at this site, also. I don't post frequently here, but I've been a daily lurker for several years now, and have learned quite a bit about sawing and drying lumber. When the economy improves, I will be expanding my business to sawing and drying quality lumber and slabs, with the furniture maker in mind.

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