Sign in to follow this  
Allan Speers

Thermo-treated wood?

Recommended Posts

Has this been discussed here, yet?

http://www.westwoodcorporation.com/what.html

Very interesting.

note something written part-way down: "The molecular structure of the thermo-treated wood is comparable with a 350-year old wood."

Hmmm. Stability, resonance

This stuff could be a huge boon to instrument makers, though standard dimensions might have to be modified as the modulus ratio likely changes. Also, I have a feeling that Spruce is not high up on the company's priority list, though. Maple yes, but probably not figured Maple and certainly not Bosnian. Still, they evidently take special orders, if you send them 10 - 12' beams.

I bet it's really hard to work with hand tools, though.

Share this post


Link to post
Share on other sites

Has this been discussed here, yet?

Maybe not that specific company, but yes... thermally processed wood has been discussed. Search for "processed" and you should find it.

I have made my last 3 violins out of processed wood. The last VSA papers (from an ancient meeting) had an article about it.

Share this post


Link to post
Share on other sites

Maybe not that specific company, but yes... thermally processed wood has been discussed. Search for "processed" and you should find it.

I have made my last 3 violins out of processed wood. The last VSA papers (from an ancient meeting) had an article about it.

Don may be an authority on the topic. Haven't observed him pushing an agenda, as much as I've seen him just posting outcomes.

Share this post


Link to post
Share on other sites

While I'm far from knowledgeable on the topic, I understand that heat treatment of wood for violins has been going on for centuries. I've read disparaging comments regarding such practices over the years.

Since it seems to be ongoing, a brief synopsis of modern thought on the topic would be of interest. Has the process been found worthwhile? What drawbacks have been noted? Have the results won over any modern makers?

Share this post


Link to post
Share on other sites

From my own results using pressure and humidity (a version of the "Plato" process), the main effects are a decrease in density, decrease in EMC (equilibrium moisture content), and getting a brown color. Modulus decreases significantly crossgrain, but very little parallel to the grain, therefore speed of sound and radiation ratio along the grain end up at higher values. Damping is also reduced. This is for spruce; maple only seems to turn brown, without much benefit property-wise.

The main use for these processes today is to create wood that is more stable and less prone to rot, essentially by removing and/or hardening the softer components in the wood. It is hard to believe that processed wood, at least in several lifetimes, would degrade or warp faster than unprocessed wood. However, due to the significant crossgrain weakening, it would be more prone to accidental damage and splitting... but NOT from shrinking.

In my testing, unpressurized heating of wood does not gain much in the way of a permanent change, other than color.

Share this post


Link to post
Share on other sites

"Modulus decreases significantly crossgrain, but very little parallel to the grain, therefore speed of sound and radiation ratio along the grain end up at higher values."

How would sound propagation differ from what one would find in an aged violin? In a relatively new one made from kiln-dried wood?

Share this post


Link to post
Share on other sites

There is some logic to the idea that the chemical changes in processing may be similar to what happens in natural aging, only faster. I don't have any direct measurements of old wood to back this up, though.

Kiln dried wood should be no different from air-dried wood; the temperatures are far too low to cause the chemistry changes of "processing". It might be possible to distort the cell structure (a bad thing) if the kiln drying is done poorly, although I have no direct evidence of that, either.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.