Thermal modification of tonewood (TMT) is an exciting new development in the guitar world. TMT uses a specialized kiln to apply heat to wood in the absence of oxygen. Under the right circumstances, such modification can improve the acoustic properties of the wood. The resulting guitars can feature improved resonance and tone. TMT guitars are much more stable; they shrink and swell less in response to changes in humidity, making them more durable and constant.
TMT is a tricky technique for several reasons. TMT applies oven temperatures to wood and, like all ” cooking,” it can be easily over done, resulting in a degradation of the acoustic properties that we seek to improve. In addition, there are several methods, and several different kiln designs, for doing thermal modification. No one is certain whether one technique is superior to the others. Recognizing this complexity, Pacific Rim Tonewoods has embarked upon the world’s first comparative study of the four main methods for thermal modification. We have engaged an international expert in this field, Prof. Alexander Pfriem of Eberswalde University, Germany. Dr. Pfriem and his research team are presently modifying spruce tonewood from PRT, and comparing the results using precise acoustic measurements. Phase I of the study will be completed in early 2016. Through this unprecedented research, we hope to gain insight into the optimal “recipe” for TMT, and use this knowledge to provide the best possible product to the guitar industry.
For a more thorough explanation of thermal modification and its applications for spruce tonewoods, please look here:
Thermal Modification of Spruce Tonewood, by David Olson, MD, MS (83kb, PDF)