Luthier Wood Questions

[marmeduke]

I'm considering starting a guitar project and I'm wondering about wood. The project could be either electric or acoustic so please comment on both. This specific question is about kiln vs air dried wood. Does kiln drying effect wood detrimentally? Should I worry only about soundboard vs back/sides on acoustic? Or should I stay away from kiln dried wood all together? What about on electrics? Both body and neck or neither? Thx...Colin

[Martin Edwards]

The key thing is DRIED

Air driying is a slower process. This means that the wood has had longer to get used to the changes in all the internal forces so SHOULD be more stable.

Bear in mind also that when you bend a side you wet it some.............

that'll be all your drying gone then, right? ;o)

Most folks would recommend keeping your wood in your workshop environment for several months to allow it to aclimatise before you attack it with tools anyway, so the method of drying becomes less important the longer you store it.

My current stash of mahogany was a bar top in a powerstation club for 40 years before being stored in a work collegue's garage for 15 more.....

I have NO IDEA how it was dried, and y'know what?

I don't care!!

[Donald A. Fortune]

I think Martin has something there-- if you hapen to be lucky enough to get ahold of a hydrometer then your "in" -- the moisture content should be arround 12%...
Most of the time when you order from a guitar makers supply house like LMII your wood is ready to use...
Good luck with your build and have fun :)
Donald

[marmeduke]

Thx guys...but I'm not asking about cosmetics or stability. My worry is about tone quality. Research has raised concerns that kiln drying can mute or detrimentallly effect tone in various ways. Has anyone run into this?

[Frank Ford]

The phrase "kiln dried" may be the issue here. We tend to think of a kiln as an oven, but in this context it's not necessarily. Kiln drying is a controlled method of seasoning wood, and it's particularly important when dealing with tropical hardwoods, some of which are prone to cracking during air drying. Depending on the wood and its moisture content, kiln drying might proceed more slowly than air drying at first.

Any number of big an small guitar factories do their own kiln drying, as do suppliers such as LMI.

If memory serves, the conventional wisdom is that air drying takes a year per inch of thickness, which means that thin wood for acoustic tops and backs can equilibrate to ambient humidity in a matter of weeks.

Now, Taylor started many of us on the track of "baking" guitar tops, that is, drying them to zero moisture in an oven, and then storing them for future use. It appears that for spruce and other acoustic top softwoods, this rough treatment leaves them much more stable, just as they would be if stored in traditional manner - covered outside for many years.

An old Martin employee said they had a treatment they called "roasting" where they would hold Brazilian rosewood backs against a heated griddle until the resins bubbled out of the wood. I believe they did that before sanding and joining, and that they felt it improved finish and glue adhesion to get rid of a bit of the resin. No need for this process to be used on sides for obvious reasons.