The Torrefaction Process... Anybody know how to cook wood? Answered
For anyone out there who is not yet familiar with Torrefaction, it is a process of "baking" wood in an over between 200 and 320 degree Celsius (392 - 608 F), in the absence of oxygen. Don't quote me on those temperatures btw... I got them from Wikipedia, and they sound way too hot based on other articles I've read.
The idea is, wood contains a lot of biomaterials like sugars, resigns, tar, and water. After you cut down a tree, these materials begin to vacate the wood through evaporation, sublimation, and all the other _'ations...It takes 100 years or so, but eventually, they all are gone, and the wood is super stable, and no longer expanding, moving, contracting and changing. This old wood is also extremely rot resistant and can withstand the elements. For this reason, Torrefied wood is used for decking and outdoor projects mostly.
However, the guitar industry has also started to adopt using it, because you have basically aged the wood 100 years in the course of a few hours. You have also increased the price of the damn guitar to the, "your firstborn child" level. I build guitars, and I cannot believe that it can be too hard to bake some wood myself. Here are the variables that I see...
1.Vessel: How to create an environment that can be brought to a specific temperature (~350-400 d F), but has also had all oxygen removed? Even if you welded together a steel box that could be locked down air-tight, and had a valve that you could pump all the air out, if you could figure out a way to heat that box to 400 d F, the water inside the wood would def. begin to boil and I imagine would be re-introducing O2. I guess you'd have to re-pump the air out every so-often until all the water was gone.
2. Temperature: Torrefication is also the exact same process that is used to turn ordinary hardwood into charcoal. I have no idea what the temperatures are, but lovely baked spruce for a guitar top has turned a slight aged tan color. But if you cranked the temp, it would eventually turn into pure carbon and be jet black like charcoal. I have no idea how to tell what temp achieves what I want.
3.) Time: I always read that Torrefied wood is baked at these temps for "several/many" hours. How would I ever know?
4.) Pressure/Flames/Bomb: I know from watching YouTube videos, that when charcoal is made, wood is superheated in an oxygen-free env. until the volatile oils, resins, etc ignite and burn off, thus leaving Charcoal. I do not want to weld together a heavy steel box that becomes a high temp pressure cooker, that blows my kitchen apart when the oils in the wood inside of it ignite.
Does anyone know what I am talking about and/or have any suggestions?