Adequate air-drying time for instrument woods?

[Eddie McRae]

This has never been an issue for me because all my woods are always kiln-dried but I now have a reason for asking. I'm located in GA and last year, the F4 tornado that ripped up most of the southeast came straight through the heart of where I live, and in the process, went straight through the heart of one of our farms. Left in it's path of destruction was a good bit of black walnut, cedar, and cherry which we had board-sawn and it's now been sticker-stacked in an opensided barn for a little over a year now. I have a friend who owns a sawmill that can kiln-dry some of it for me but I'm wondering if that's even needed. What is adequate drying time in a climate such as the south-eastern U.S.?

[Bob Gramann]

I have some walnut on the way to being a guitar that fell in 2007 or 2008 (in Virginia). It was sawn in 2008. I stored the quartersawn 1" planks in my shed for three years before I brought it inside and resawed it to guitar thickness. I weighed it when it after I sliced it and waited until it stabilized in my humidity controlled room. It didn't take long to settle at its final weight and seems to have been stable since then. I've heard others claim that 6 years is a good time to wait. I was impatient and it seems to be stable now.

[Michael Lewis]

The thinner you cut it the quicker it will loose it's moisture. The old "rule" is it needs to dry a year for each inch of thickness but I have found walnut often takes longer than that, and sometimes considerably longer.

It is best to cut to near, but a bit over size, to the size you will use while the wood is still wet so it dries more quickly and evenly. If you dry thick billets for a year or two and cut it to final size before it is dry the inside will have more moisture content than the outside surfaces, this causes the wood to shrink on the freshly cut surfaces which means cupping and warping. Weigh the wood and make notes of the weight and date, then do it again in a month or two, and again until it stays at one weight. As long as it looses weight it isn't dry.

I suppose you could seal a billet in plastic for a month or two to equalize the moisture content throughout, and then resaw it to your desired sizes and proceed to sticker and stack for a quicker drying process . Bruce Harvie suggested a method of drying green wood in a plastic garbage bag where you place your wood in a bag and seal it and set it in the sun for a day, remove the wood and turn the bag inside out to get rid of the accumulated water and put the wood back in the bag and seal it again for the next day. I don't know how long it would take to dry the wood but this would get the most moisture out with the least stress to the wood, which would speed the overall process significantly. I have not tried this process, I just air dry thick billets and wait several years for them to dry.

[Steve Senseney]

I place wood in my car when I want to quickly dry it. In the summer, while the car sits out side, it will get to 150 fahrenheit during the day.

During winter months, it still dries more quickly because of the heater running, without adding any moisture to the air.

[Dick (DT) Trottier]

Hi Steve,
Brilliant. I'd imagine a car trunk makes a good kiln in the summer!

[Clay Schaeffer]

Drying the wood too quickly can cause case hardening. Cutting the wood too thin initially can cause the boards to warp badly. If it has already air dried for a year at a 1 inch thickness, you should be able to resaw it to 1/4 inch, sticker it and allow it to finish air drying for a couple months more.

[Eddie McRae]

Thanks for all the input. I'll most likely resaw some of it and then re-sticker for a few months before I try using it.

[John Hamlett]

Drying times for wood vary widely with species, thickness, drying conditions and so forth. The 1 year per inch rule is pretty safe because most woods dry much faster than that in good drying conditions.
Dry is one thing, however, and "seasoned" is another. There is some disagreement, and even controversy, about how much benefit there is to tonewood from seasoning, and the only thing I know for sure that goes on during extended storage is gradual loss of hemicellulose, but most instrument makers wait a number of years for wood to season before using it.
As mentioned, weighing a sample repeatedly will tell you when it has reached equilibrium moisture content (EMC) where it is stored.

[Robert Eason]

When my sassafras was resawn by myself and a luthier friend of mine he recommended that I sticker them and place the stacks in my attic (actually my man cave upstairs) for at least 6 months as it is nice and warm there. The humidity is fairly constant I might add being as it is inside. While I didn't check with a meter it has stopped moving and is now being used in my 1st and 2nd builds which I'm doing at the same time.

[Alan Carruth]

Most wood will have some built-in stress that gradually relaxes as it seasons. The longer the better, though, since I'm not sure it ever totally works itself out. I cut some reaction wood a few weeks ago from a board of spruce that was resawn from a barn beam that was said to be between 200-400 years old (it's Austrian). I noticed the other day that the straight piece I made is now a little bit warped. I probably would have been a pretzel if it had been cut that thin green, but it's still not 'stress free'.