Bruce Tai

Secrets in the wood (Stradivari's maple)

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13 minutes ago, thirteenthsteph said:

It is one of Stradivari's secrets that he indeed invented the deodourant. 

If I understand it correctly, he actually invented deodorant for use not the violin, since the wood smell so badly after being fumigated....

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5 hours ago, David Burgess said:

Except for boron and aluminum, aren't all of these present in human sweat?

Aluminum: Isn't that a common ingredient in anti-perspirants?

David, one must dig deep into the murky accounts of personal amusements common in the times of the Ancients.  My understanding is that a favored pastime was a game in which players flapped their arms vigorously on two sides of a table, moving air in the direction of the opposing team, seeking to send a feather across and over the edge of the table.  The Italian name roughly translates as BO.

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20 minutes ago, Berl Mendenhall said:

Here is something that no one is talking about. What if those old guys were wrong and the treatment did nothing.

Then they weren't "wrong" ... it didn't do anything bad.  And, assuming they actually did some treatments, we don't know what the purpose was.  Perhaps it was just to prevent fungus, mold, and insect attack (which sounds reasonable to me), and then they may have been right.

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2 hours ago, Don Noon said:

It is tempting (and many people appear to fall into the trap) to focus on the mysterious treatments, added chemicals, and magical properties that result.  However, I have not yet seen the connection.

In digging into the appendixes, the bottom line appears to be an increase of approximately 0.75% by weight of metals in the old maple vs. the new samples.  If it is dead weight, I would challenge anyone to tell an acoustic difference.  Cellulose is not going to be stiffened by this stuff, so the only question is if these added metals can somehow stiffen or polymerize the hemicellulose and lignin.  I'm a skeptic there.

Somewhat glossed over is the natural aging effect of hemicellulose decay and reduced EMC.  That is a comparatively huge known effect... about 4% by weight of dead water, a known damping material.  Any other natural age-relate polymerizing effects (and I expect there are some) are not quantitatively known.

So, bottom line:  I don't see that a tiny amount of metals or salts would do much other than make the wood less appetizing for bug and fungus, although that could help a wooden instrument survive 300 years without excessive degradation.  However, the effects of natural aging appear to be comparatively large acoustic factors.  This has guided what I have chosen to do, which includes some fungicide/pesticide treatments for minimizing harmful degradation, and accelerated aging for acoustic effects.

For a real expensive and heavy piece of French furniture there is a record of it's as new weight. In 360 years it seems to have lost some  8-9% of it for whatever reason.

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3 hours ago, thirteenthsteph said:

It is one of Stradivari's secrets that he indeed invented the deodourant. 

Possibly. If he was less stinky than other makers of the time, that might have contributed something to his success.

3 hours ago, Julian Cossmann Cooke said:

David, one must dig deep into the murky accounts of personal amusements common in the times of the Ancients.  My understanding is that a favored pastime was a game in which players flapped their arms vigorously on two sides of a table, moving air in the direction of the opposing team, seeking to send a feather across and over the edge of the table.  The Italian name roughly translates as BO.

If I'm starting to understand your mind even a little bit, I'd guess this is a twist on the Oberlin "halitosis" game, where one tries to blow a ping-pong ball over the opposite side of the table, versus opponents who are blowing in the other direction.

The "halitosis" game did not originate at Oberlin, but the Oberlin version took on some fun and interesting twists. :D

Looking forward to trying the arm-flapping version next year. With our current version, most of the casualties have been due to hyperventilation. With aggressive arm flapping, the heart attack rate might rise.

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23 minutes ago, Don Noon said:

Then they weren't "wrong" ... it didn't do anything bad.  And, assuming they actually did some treatments, we don't know what the purpose was.  Perhaps it was just to prevent fungus, mold, and insect attack (which sounds reasonable to me), and then they may have been right.

If it was only a means of pretreating against infestation, diatomaceous earth would have been a possibility. There are some high quality DE deposits in Europe,  especially Spain,  I read.  Or what about volcanic ash deposits? Either would explain finding aluminum and some of the other stuff. But without knowing what silicate were found,  if any, it's just an idea. 

Why wouldn't they have tried to treat the wood for an acoustic result? Or maybe acoustic results were just a bonus.  

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4 hours ago, not telling said:

Why wouldn't they have tried to treat the wood for an acoustic result? Or maybe acoustic results were just a bonus.  

Since we don't have any evidence of WHY they treated wood (assuming for the moment that they actually did intentional treatment), it is possible that there was an intended acoustic benefit.  However, at the moment there is no evidence or logic for added chemicals actually doing anything acoustically beneficial, and that's what seems most important.

Just because Cremonese makers (maybe) did something doesn't mean it did anything.

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39 minutes ago, Don Noon said:

Since we don't have any evidence of WHY they treated wood (assuming for the moment that they actually did intentional treatment), it is possible that there was an intended acoustic benefit.  However, at the moment there is no evidence or logic for added chemicals actually doing anything acoustically beneficial, and that's what seems most important.

Just because Cremonese makers (maybe) did something doesn't mean it did anything.

Right. My point was that just because there may have been wood treatment, it did not necessarily produce an improvement in tone. 

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There is no question as to whether salts were used historically as fungicides or insecticides - they still are.

I don't really buy into the idea that this would also be done for tonal results. But if someone could demonstrate that treated woods were unequivocally more successful tonally, and that this was unique to golden period Cremonese instruments, I would stir myself and pay attention.

I'm with Don on this one. I believe that a violin which sounded great to start with, and which has had 300 years of wood deterioration possibly held back by the use of salts could well be a winning formula.

But impossible to reproduce ...!

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There is no solid evidence to suggest that multi-step treatments with different mineral solutions have an effect on wood acoustics, but these possibilities need to be considered:

1. The removal of sap residues and wood extractives. Ancient Chinese books emphasize that it is critical to remove sap residues to get clear tones in guqin (7-string zither). The purpose of soaking wood in mineral solutions may be removing sap and extractives. 

2. If the treatment was alkaline (wood lye or lime water), it may promote some hemicellulose decomposition. I don't think this happened in Cremona, but ancient Chinese did recommend this for tonewood processing. 

3.  Having some hygroscopic salts in the wood will help retain more moisture on cold winter days and prevent excessive shrinking, which may be acoustically beneficial in the long run due to better protection. 

4. Metal ions may crosslink wood fibers to compensate the breakdown of hemicellulose over time, stabilizing the ultrastructure of wood. This may be acoustically beneficial in the long run.  

5. Treatments may alter the surface properties of wood. Treated wood may be easier to smooth or react differently to stain/wood sealer (as seen in Brandmair's book). Wood surface treatment may also have some effects on acoustics. 

6. Some of the minerals are clearly fungicides and pesticides. 

All six points listed above are of speculative nature. But are we really sure that none of these things matter in the long run? 

   

 

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30 minutes ago, Bruce Tai said:

All six points listed above are of speculative nature. But are we really sure that none of these things matter in the long run? 

Over 300 years, there's no way we can tell with certainty what any of these things might do.  But, in the near-term, I think there's plenty of evidence that nothing good happens right away.

I have tested a bunch of stuff on my own and samples sent from others, wood soaked in borax, iron salt, zinc, salt, various other salts, weak alkaline solutions, etc., and none have done diddly to the important acoustic parameters of density, modulus, and damping, except for higher concentrations that made the wood heavier.  Not only that, but getting any solutions into spruce wedges takes a lot of effort; even with alternating cycles of pressure and vacuum submerged in a chamber, it's sometimes impossible to get full wetting.  And forget about just sticking the wood in a vat.  Maple is a lot easier, and it would be interesting to see if the Cremonese spruce showed anything unusual.

In any case, until someone can show significant quantitative effects of any of these chemical treatments on wood acoustic properties (and spruce in particular), I'm staying a confirmed skeptic.

1 hour ago, martin swan said:

I believe that a violin which sounded great to start with, and which has had 300 years of wood deterioration possibly held back by the use of salts could well be a winning formula.

But impossible to reproduce ...!

Don't be too sure about that last one. ;)  However, I would go along with "But impossible to prove it has been reproduced."  Or, "Even if reproduced, nobody will really care anyway, because they secretly like the sound of new violins but won't admit it, except for the diehard old violin crowd, but they are in the minority."

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11 minutes ago, Don Noon said:

Over 300 years, there's no way we can tell with certainty what any of these things might do.  But, in the near-term, I think there's plenty of evidence that nothing good happens right away.

I have tested a bunch of stuff on my own and samples sent from others, wood soaked in borax, iron salt, zinc, salt, various other salts, weak alkaline solutions, etc., and none have done diddly to the important acoustic parameters of density, modulus, and damping, except for higher concentrations that made the wood heavier.  Not only that, but getting any solutions into spruce wedges takes a lot of effort; even with alternating cycles of pressure and vacuum submerged in a chamber, it's sometimes impossible to get full wetting.  And forget about just sticking the wood in a vat.  Maple is a lot easier, and it would be interesting to see if the Cremonese spruce showed anything unusual.

In any case, until someone can show significant quantitative effects of any of these chemical treatments on wood acoustic properties (and spruce in particular), I'm staying a confirmed skeptic.

Don't be too sure about that last one. ;)  However, I would go along with "But impossible to prove it has been reproduced."  Or, "Even if reproduced, nobody will really care anyway, because they secretly like the sound of new violins but won't admit it, except for the diehard old violin crowd, but they are in the minority."

I am not trying to be argumentative, but it sounds like you are saying the properties we ascribe to sound quality are not measurably affected so the so7nd quality could not be affected. Has anyone tried the treatments and tested for 5he impact on the sound itself. And i am not even how one would test that, so that you knew it was the treatment.

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1 hour ago, Frank Nichols said:

I am not trying to be argumentative, but it sounds like you are saying the properties we ascribe to sound quality are not measurably affected so the so7nd quality could not be affected. Has anyone tried the treatments and tested for 5he impact on the sound itself. And i am not even how one would test that, so that you knew it was the treatment.

Sounds like you have passed over the observable elephant in the room:  natural aging, natural hemicellulose degradation, and 40% reduction in moisture content, as described in the research.  I have pretty good evidence that these DO measurably affect acoustic properties, and have a hard time believing a tiny  amount of added stuff would do more than that.  And it appears to be a waste of time to try to hear tonal effects in a treatment when there are no measurable changes in the wood.   Wood properties are so widely variable, as well as construcion variables, that this looks like a guaranteed failure... or great success, if the experimenter is judging the results.

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Bruce, I read the article form the OP but I'm not sure how did you measure the increase of the elements... When the wood loses some weigth over the years but the amount of mentioned elements stays constant it results in increase relative to the new weight of wood...

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On 9/10/2017 at 1:37 PM, David Burgess said:

Possibly. If he was less stinky than other makers of the time, that might have contributed something to his success.

If I'm starting to understand your mind even a little bit, I'd guess this is a twist on the Oberlin "halitosis" game, where one tries to blow a ping-pong ball over the opposite side of the table, versus opponents who are blowing in the other direction.

The "halitosis" game did not originate at Oberlin, but the Oberlin version took on some fun and interesting twists. :D

Looking forward to trying the arm-flapping version next year. With our current version, most of the casualties have been due to hyperventilation. With aggressive arm flapping, the heart attack rate might rise.

If you are beginning to understand the way my mind works, David, I advise being very afraid.  And yes, I suspect there is a link between BO and halitosis.  Another topic for one of our intrepid researchers.  Does the heart attack come before the rotator cuff tear or after?

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As I've passed through these first years experimenting and researching, I've been open to trying almost anything that I thought might potentially have been used in old making.   I 'tawed' one violin.   This is normally a treatment to prepare leather, but I thought I'd try it.   Tawing is meant to meant both to stabilize a skin, but also to leave it very soft and supple.  I figured that if any of that translated to the wood, it might be a positive.   Anyway, my 'tawing' process consisted of treating the wood with a brine of vinegar, salt, and alum -- mixed with egg yoke.   This was applied and allowed to sit on the instrument for hours, then was thoroughly cleaned away and the process repeated several times.      While certainly a long shot to be something they actually did regularly, I can at least imagine that some drunken old Italian maker might have tried it at least once.  

Did it have an effect???    I don't think or anyone else could look at this violin and say 'that wood was tawed'.    On the other hand, this was one of my early experimental instruments, and it's ended up as principal violin, which I play daily.   And I absolutely love playing it.    The tawing certainly didn't hurt.

I'm finally coming out of my years long research project.  I'm back in the workshop beginning to build a pair of twin violins embodying my research on the geometry seen in classical making.  I'm thinking I might make just a very differences in the twins.   Perhaps I'll taw on of these.

 

 

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On 9/11/2017 at 4:33 PM, Don Noon said:

Sounds like you have passed over the observable elephant in the room:  natural aging, natural hemicellulose degradation, and 40% reduction in moisture content, as described in the research.  I have pretty good evidence that these DO measurably affect acoustic properties, and have a hard time believing a tiny  amount of added stuff would do more than that.  And it appears to be a waste of time to try to hear tonal effects in a treatment when there are no measurable changes in the wood.   Wood properties are so widely variable, as well as construcion variables, that this looks like a guaranteed failure... or great success, if the experimenter is judging the results.

Amen.

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On 09/11/2017 at 2:35 PM, Don Noon said:

Over 300 years, there's no way we can tell with certainty what any of these things might do.  But, in the near-term, I think there's plenty of evidence that nothing good happens right away.

I have tested a bunch of stuff on my own and samples sent from others, wood soaked in borax, iron salt, zinc, salt, various other salts, weak alkaline solutions, etc., and none have done diddly to the important acoustic parameters of density, modulus, and damping, except for higher concentrations that made the wood heavier.  Not only that, but getting any solutions into spruce wedges takes a lot of effort; even with alternating cycles of pressure and vacuum submerged in a chamber, it's sometimes impossible to get full wetting.  And forget about just sticking the wood in a vat.  Maple is a lot easier, and it would be interesting to see if the Cremonese spruce showed anything unusual.

In any case, until someone can show significant quantitative effects of any of these chemical treatments on wood acoustic properties (and spruce in particular), I'm staying a confirmed skeptic.

Don't be too sure about that last one. ;)  However, I would go along with "But impossible to prove it has been reproduced."  Or, "Even if reproduced, nobody will really care anyway, because they secretly like the sound of new violins but won't admit it, except for the diehard old violin crowd, but they are in the minority."

If low wood damping is important for violins then the attached reference on treating spruce wood might be helpful:

fulltext.pdf

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26 minutes ago, Marty Kasprzyk said:

If low wood damping is important for violins then the attached reference on treating spruce wood might be helpful:

fulltext.pdf

Interesting, but it's not all good.  A considerable mass of additive is needed to have an effect.  It increases density AND decreases modulus... pretty significantly.  I don't think it would be worth it for violins.

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On 2017/9/12 at 5:40 AM, HoGo said:

Bruce, I read the article form the OP but I'm not sure how did you measure the increase of the elements... When the wood loses some weigth over the years but the amount of mentioned elements stays constant it results in increase relative to the new weight of wood...

The original research article with full details is here, open access for all:

http://www.pnas.org/content/114/1/27.full

Thanks to Chimei Museum for sponsoring the open access publication fee, so that everyone can read this freely. 

 

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On 2017/9/12 at 4:33 AM, Don Noon said:

Sounds like you have passed over the observable elephant in the room:  natural aging, natural hemicellulose degradation, and 40% reduction in moisture content, as described in the research.  I have pretty good evidence that these DO measurably affect acoustic properties, and have a hard time believing a tiny  amount of added stuff would do more than that.  And it appears to be a waste of time to try to hear tonal effects in a treatment when there are no measurable changes in the wood.   Wood properties are so widely variable, as well as construcion variables, that this looks like a guaranteed failure... or great success, if the experimenter is judging the results.

From your observations you brought up many good points, Don Noon. 

First, minerals don't easily penetrate the wood as you said. We soaked think shavings of maple in 1% alum solution for 3 days and after rinsing only detected weak aluminum signals in the wood. When we measured significant minerals from deep inside the Strad neck samples, I am sure that some soaking was involved. 

Aging matters a lot, and it is possible that the treatments mainly assist better aging. To age to into a mature sound without losing the brilliance is very unusual when things are breaking down inside.  Perhaps it can be considered as chemically assisted aging. And I am not just making this up. Supportive evidence for such processes will be presented in our next paper.

The real surprise is that Amati, Stradivari, and Guarneri were experimenting with the mineral formulations for over 120 years based on our available samples. This will become evidence in our next paper. If it was only for preservation, I think the Amati instruments are preserved just fine and why change? I think Stradivari and del Gesu were really trying to achieve something different when they conducted chemical experiments.  I suspect that their ability to sense meaningful acoustic changes in wood is still more informative than the routine acoustic tests that we know how to perform at this point. 

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10 hours ago, Bruce Tai said:

 I suspect that their ability to sense meaningful acoustic changes in wood is still more informative than the routine acoustic tests that we know how to perform at this point. 

 

Hi Bruce,

What is your evidence that they, in fact, sensed meaningful acoustical changes with chemical applications? Were they instead experimenting with varnish grounds on top of wood preservatives? 

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11 hours ago, Bruce Tai said:

First, minerals don't easily penetrate the wood as you said. We soaked think shavings of maple in 1% alum solution for 3 days and after rinsing only detected weak aluminum signals in the wood. When we measured significant minerals from deep inside the Strad neck samples, I am sure that some soaking was involved. 

 

I've heard of some makers soaking neck blocks to prior to and as they carve the scroll.  

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