drying

[Tom Krueger]

Hey guys. Do you guys know, is it OK to use air dried lumber for furniture? Just talked to a guy said he had some qswo tthat has been drying for around 20 years.

[Mel Fulks]

Sure it's ok. That's all there was for a long time . Air dried moves more , but some say no. Any way ,quarter sawn wo is
a good stable wood....and I'm betting your house has central heat and AC .

[Cody Colston]

Lumber for indoor furniture needs to be ~7% - 8% moisture content. Air-dried is fine if it has been put somewhere it can reach that value. It it's indoors, even in an unheated building, it will air dry more than when outside because it doesn't see the near-100% humidity that occurs early mornings in most places. Ultimately, though, the MC needs to be brought to an acceptable value via heat, low RH and air flow before using it for indoor furniture.

Lumber used before modern kiln drying was mostly acceptable for furniture because the homes were not well sealed or air conditioned as they are now. Even then, however, some of the lumber was dried via fires to bring the moisture content down. Look through a period furniture book at pieces that were built in the 18th century. Many of those pieces that survived until the present are severely warped, especially table tops, because the lumber was not dried sufficiently when used...and that's just the ones that survived. There is a reason museums are humidity controlled.

Even "name" woodworkers like Garrett Hack, who use only air-dried lumber will bring the lumber into the heated shop and let it dry to the 7% - 8% MC value before working it. In effect, that lumber is no longer air-dried but kiln dried since the heated shop has the same effect as a kiln, only somewhat slower.

It doesn't matter how long the lumber has been air drying once it reaches equilibrium moisture content. Once it's there, it will get no drier unless its environment is changed.

So, the answer is to check the MC...at the wood core, not on the surface and see if it is dry enough for indoor furniture, again 7% to 8% MC, depending on where you live.

[Mel Fulks]

Well, the warps were mainly caused by wiping them with damp clothes. Water on one side makes cells on that side swell.
Since their movement is restricted by the lower dry cells ,they become oval ,then when they dry out they shrink occupying less
space than they did when dry . " Compression ring set".

[roger wiegand]

That's how it was done for thousands of years. Seems to have worked. Just like kiln-dried wood it needs to be in moisture equilibrium with its environment to be stable.

[Frank Drew]

A lot of the mildest, nicest-working wood I've used has been air-dried by me. As noted, absolutely bring it indoors for a fair amount of time before working it up.

Of course, how it was stacked and stored while air-drying can make a ton of difference.

[John TenEyck]

What Cody said. We only see the furniture from yesteryore that survived, and much of that has problems. The stuff that was built with no regard for control of MC self destructed long ago. So get a moisture meter and check the MC at the core. If it's been stored anywhere except indoors it's likely much higher than 6 - 8%. WO is not very stable, which is one of the primary reasons it often is quarter sawn, but whatever isn't checked at this point will likely be fine once it's really dry. How long it will take to get down to 6 - 8% MC depends upon the environment you put it in, but you will be looking at weeks or months unless you force dry it.

John

[Art Mann]

Anyone who doubts the durability or desirability of lumber that is not kiln dried should make a pilgrimage to Colonial Williamsburg, VA. They conduct demonstrations and seminars on how furniture was made before the US was even existed as a country. The whole town is full of exquisite pieces built in the 1600's and later. Some of this furniture built from air dried lumber has existed in its present form with out alteration or temperature/humidity control for 3 centuries.

[John TenEyck]

I was just in Colonial Williamsburg and took special note of the furniture in the buildings and there are many fine pieces, to be sure. The fact that some very nice pieces of furniture have survived all those years wasn't luck, it's because the folks who built them knew what they were doing and made accommodation for wood movement. While those craftsmen may have used AD lumber that was well above 6 - 8% MC, the buildings of the time were drafty and poorly heated, and never reached low humidity for sustained periods of time like in a modern house. Still, the pieces that disregarded the requirement to accommodate wood's need to move with humidity self destructed. What you have left are the very best examples of what the craftsmen of the time made.

AD or KD, it doesn't matter. What does matter is making sure the wood is at EMC with your shop and accommodating movement over the range of humidity the piece will be exposed to in use.

John

[Cody Colston]

AD or KD, it doesn't matter. What does matter is making sure the wood is at EMC with your shop and accommodating movement over the range of humidity the piece will be exposed to in use.

John

That is absolutely correct. 12% MC wood that will live in a 12% EMC environment is not a problem. Subject that same wood to the 5% EMC that it can see indoors in the winter and there will likely be problems, sometimes catastrophic problems.

[Prashun Patel]

In fact, if you are surfacing the lumber by hand, air dried stock can be a joy vis-a-vis kiln dried. It just seems to like to be planed more than kd.

Clear, QSWO is fantastic for furniture. Stable and beautiful.

One caveat with air dried lumber, it can have bugs. So, if you are acclimating it indoors, beware. Some places will kd it for a short period to kill organisms.