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I am currently in the process of building my first guitar basically totally from thermally modified wood. This is frequently referred to as "torrefied", but the wood I am using has been done with the Thermowood process developed in Finland, so is more properly called "thermally modified". Everything in this guitar except the linings, fingerboard, bridge, bindings and other appointments will be from treated wood.

Since I don't typically see long build threads posted on this forum, I will just provide a link to the posting.

http://luthiercom.org/phpBB3/viewtopic.php?f=71&t=5230

Just thought I would share this with a larger audience FWIW. I will definitely be building more.

Questions and comments are welcome.

Grant Goltz

Hi Grant,
Good to hear you are still around. Hope the wife is well too.
Good luck on the build!

Cool bracing pattern. Hope you can post a sound clip when it's done

It is my understanding that torrefaction is done using a vacuum (low oxygen environment), which prevents torching the wood. Correct me if I'm wrong, but I only see a standard oven in the photos you posted. How do you prevent to wood self-BBQing in an oxygen environment ?

_________________
If thee meddle with dragon kin, thou will become crunchy and good with ketchup.

First of all, wood will not "torch off" at 380 F. Secondly the aluminum foil wrap keeps air from contacting the wood surface, so it can't, anyway. There seems to be some misunderstandings and confusion concerning various process of "heat treating" wood. I don't believe any of the processes use a vacuum. I do not know the details of the patented "Torrefaction" process, other than it was originally used as an alternative to chemical treatment for wood preservation, primarily at higher temperatures than most guitar wood is treated.

The patented "Thermowood" process was developed in Finland, originally for the same purpose. This is the process that my wood (other than the guitar sides) has gone through, and is the same process being used by several major instrument manufacturers, such as Fender, Gibson, and Music Man, to name a few. In fact, my wood has been on the same pallet as some of their's. This process heats wood to 180 C with no attempt to create a vacuum or introduce an inert atmosphere. Actually there is a slight positive pressure, about the equivalent to a breath of air, in the kiln

To my knowledge, there are currently 2 such kilns (manufactured by Jarvis) in operation in the United States, one here in northern Minnesota, and the other in Indiana. I am very familiar with the Minnesota operation. Just for grins, here is the inside of a Thermowood kiln looking out


And here is a pallet of my wood, mostly spruce tops with a few back billets and some 12/4 HOG for necks, just out of the kiln

The top 4 layers are somebody else's electric guitar bodies.

As I said, I treated my sides in a conventional oven after bending because the treated wood is almost impossible to bend. I first discussed this with the guy who operates the Thermowood facility and showed him a couple of samples. He said I was ending up with essentially the same thing. This works because the bent side has already been set into a shape by the bending process. I expect that a flat back plate would turn into a potatoe chip

Grant