When is wood ready to build with?

[Szk]

I have some Osage Orange that was cut into 1" planks a year ago. It was then thinned down to 1/4" about 3 months ago. Some of it i've now sanded down to .150". It's been stickered and air dried the whole time. So i wonder what you guys think about it being ready for using in guitar builds in 3 months time. You think it's ok to use once it's down to 6% moisture content, or does it still need to be seasoned? I was hoping to be able to use it this winter, but don't want to run into problems.

[Szk]

and, is there a way to speed up the seasoning process? Don't have a kiln.

[LouieAtienza]

In theory mastergrade instrument woods are always air dried, where kiln drying can ruin the integrity of the wood cells. Fine for cabinetry, but maybe not so much for wood we want to prepare as thin as possible for a responsive instrument.

Usually, you would need about one year for every inch thickness. Now that you have the board resawn and stickered, it's just a matter of having them at a steady moisture content (maybe about 6%) and in a controlled humidity environment... Make sure the ends are always sealed to prevent end checking.

[John Arnold]

Speed up the drying by putting a fan on the stickered wood.
Seasoning is best accomplished by subjecting the wood to varying temperatures and humidity. In other words, in outside conditions, but protected from rain and snow. This process relieves the stresses in the wood that are caused by the fact that it dries from the outside in.
I have an unheated shop building that serves well for this part of the process....I leave the windows open.
Depending on the thickness, the wood I process may stay in the shop for over a year, after which it may be as low as 10% MC. Here in the sunny South, the MC will not get much lower than that outside. After that, I bring it inside under humidity control, and wait for it to equalize. Even at this point, stickering and using a fan is good practice, particularly if you are in a hurry. With a fan, thin wood should go from 10% to indoor equilibrium in less than a week.
You can tell when thin wood is equalized by laying one piece on a flat surface, exposing the top side. If the top side goes concave, that means the wood is still losing moisture to the air. Flip the wood over, and let it flatten. If it continues to curl again, repeat the flipping process until remains flat. At that point, the wood is in equilibrium with the ambient air.
If your wood is truly at 6% moisture content (which means in equilibrium with air that is about 30% RH), I assume that means that you now have it stored in humidity-controlled conditions. If that is the case, then it should be fine to use.

[Szk]

Thank you for the explanation John. Very helpful. Not climate controlled, currently around 50% RH, but come wintertime my indoor humidity is down to 25% (in Canada).