Bruce Tai

Secrets in the wood (Stradivari's maple)

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1 hour ago, Philip Perret said:

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

Philip, maybe that was so the would be easier to carve?

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2 hours ago, Michael_Molnar said:

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? 

With only some wiggle room it is possible to fit a square peg in a round hole.

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On 9/11/2017 at 4:40 PM, 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 changes in weight are small, but the compositional changes are quite large.  The compositional data are in Table S10.  Look for the supporting information (SI).

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The damping qualities of spruce might be important for violin tops.  The below reference describes how treating spruce with pernambuco extracts reduces damping

On 9/11/2017 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 the old Italian master treated their wood is some manner it would be helpful to discover what they they did to   avoid repeating it.

 

 

Journal of Wood Science

December 1999, 45:470

Vibrational property changes of spruce wood by impregnation with water-soluble extractives of pernambuco (Guilandina echinata Spreng.)

  • Masahiro Matsunaga
  • Kazuya Minato
  • Fumiaki Nakatsubo
    •  
    •  
    •  
  1. 1.
Original Article
Received: 
28 January 1999
Accepted: 
24 March 1999

Abstract

Sitka spruce (Picea sitchensis Carr.) was treated with water-soluble extractive components of pernambuco (Guilandina echinata Spreng. syn Caesalpinia echinata Lam.) by two methods: impregnation under evacuation using an aspirator and repetitive surface application using a brush. The influence of these treatments on the vibrational properties were examined. The loss tangent (tan δ) of the impregnated specimen decreased, up to nearly a half of its original value, with increasing weight gain. It is suggested that the decrease in tan δ results from impregnation of the extractive components into the amorphous region of cell walls, forming secondary bonds between matrix substances. The surface application of the extractive components, on the other hand, hardly brought about the desirable change in vibrational properties.

Key words

Pernambuco Vibrational property Extractives Impregnation Musical instrument 

Part of this work was presented at the 47th annual meeting of the Japan Wood Research Society, Kochi, April 1997, and the 48th annual meeting of the Japan Wood Research Society, Shizuoka, April 1998

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On 15. 9. 2017 at 2:55 PM, La Folia said:

The changes in weight are small, but the compositional changes are quite large.  The compositional data are in Table S10.  Look for the supporting information (SI).

Thanks for that, didn't have the time to read the whole appendices.

BTW, is there a chance that the old pieces were contaminated with glue  from construction (hide or casein) while modern samples were from clean unused tonewood.

What elements would HG add?

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It does seem like some of these minerals could come from sweat, as previously mentioned. 

I was going to make a Sodium joke but, na.

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Bruce, I'm sorry, but going out to prove ideas is not science.  Rather, science tries to disprove ideas.  If you are in love with your ideas you may make serious mistakes (like neglecting contrary evidence, or demonizing your critics).  I think that you need to do some reading about how science is properly done.   Something seems very wrong here.

"Joseph Nagyvary made some bold hypotheses and went out to prove them. Nagyvary got some of it right, and we expanded his findings"

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On 9/22/2017 at 7:37 PM, TimDasler said:

I was going to make a Sodium joke but, na.

Li K! :)

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On 2017/9/12 at 2:06 AM, Bruce Tai said:

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? 

   

 

The top and back of a Chinese guqin are as thick as a dinner table. The top of a guqin is made by Chinese parasol(梧桐) that really needs rain, water or something soaking and long period of sun tanning to remove acid and tannin. But the weight, dampling factor and Young's modulus are what violinmakers don't want.

In my experience in playing good new guqin and listening some hundreds years old guqins playing in front of me, they have totally different sound. To me, the material of guqin plays a major role to make a good guqin. Try put a tuning fork on different dinner tables and hear the sound. In the book 洞天清錄,it says if you get the old wood, you may make a guqin better than master Chang and Lei( strad and del gesu in guqin making). 

But making a good violin is not only wood. 

 

In the same book, metal,copper , clay, bone powder ground is mentioned. But guqin ground and varnish are thicker than wall. Some Cremonese ground is thin and the pores are open.

The book also says whatever how you treat the wood, it's not better than natural aging.

i am curious what cremonese makers have used on the neck and inner size. How do you know the minerals are not from the long time playing dirt or copper fingerplane, ancient sand paper?

Edited by SFTong
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On 2017/9/24 at 11:11 PM, Luigi said:

Bruce, I'm sorry, but going out to prove ideas is not science.  Rather, science tries to disprove ideas.  If you are in love with your ideas you may make serious mistakes (like neglecting contrary evidence, or demonizing your critics).  I think that you need to do some reading about how science is properly done.   Something seems very wrong here.

"Joseph Nagyvary made some bold hypotheses and went out to prove them. Nagyvary got some of it right, and we expanded his findings"

 

Interesting point.

I guess my motivation is to disprove that Stradivari did not possess any secret. The null hypothesis is that his wood is nothing special, just wild maple. But its elemental composition is so strange that the null hypothesis has to be rejected. The hard evidence suggests that he treated his wood chemically, and we did not know about it. The fact that we did not recognize chemical preservatives as an integral part of the Cremonese method makes it a lost secret, only to be recovered by modern science. 

I then wanted to disprove that Stradivari did this trivial trick out of the blue. So I checked Girolamo Amati's wood and it was chemically treated, front and back. Amati had a simpler chemical recipe and Stradivari and Guarneri expanded it by adding more chemical substances. Since we all agree that Amati, Stradivari, and Guarneri were genius makers, this chemical formulation must have mattered a lot for them. So I disproved that (in my next paper) the Cremonese invented violin making based on natural, air-dried wood. They were never into using natural wood, and insisted on applying chemical treatments. I cannot prove its acoustic influence right now, but no one can disprove it either. We don't know exactly how they did it and how things are affected hundreds of years later.  

Technically we cannot prove anything but only falsify something which is the opposite. But there is no need to get into logical games. In experimental science, we present measured facts and offer logical explanations.   

Cremonese masters never intended to build their violins using natural wood. This is a historical fact and the proof will be presented in my next paper. Whether or not this new discovery matters entirely depends on each person's perspective. 

Oh, by the way, I am writing a new paper to show that Andrea Amati and Gasparo da Salo were mimicking the baritone voice with their newly invented violins. Stradivari was able to push it to the alto voice. This is based on formant analysis and it will hopefully be published soon. Geminiani wrote in 1751 that the ideal tone of the violin shall "rival the most perfect human voice." I think Amati and Stradivari were trying to do exactly that.   

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On September 24, 2017 at 11:11 AM, Luigi said:

Bruce, I'm sorry, but going out to prove ideas is not science.  Rather, science tries to disprove ideas.  If you are in love with your ideas you may make serious mistakes (like neglecting contrary evidence, or demonizing your critics).  I think that you need to do some reading about how science is properly done.   Something seems very wrong here.

"Joseph Nagyvary made some bold hypotheses and went out to prove them. Nagyvary got some of it right, and we expanded his findings"

Tai’s research is pseudoscience by definition: Extraordinary claims backed-up by unverifiable, unreproducible, and incomplete data and presented with phony statistical analyses.  

As Carl Sagan famously said, “Extraordinary claims require extraordinary evidence.”

Tai’s work has plenty of the former and none of the later. It fails the Sagan Standard.

This has all been discussed in an earlier thread, and I don’t plan to rehash it here.

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27 minutes ago, GeorgeH said:

Tai’s research is pseudoscience by definition: Extraordinary claims backed-up by unverifiable, unreproducible, and incomplete data and presented with phony statistical analyses.  

As Carl Sagan famously said, “Extraordinary claims require extraordinary evidence.”

Tai’s work has plenty of the former and none of the later. It fails the Sagan Standard.

This has all been discussed in an earlier thread, and I don’t plan to rehash it here.

What on Earth is The Sagan Standard ??? Who's Sagan ???? :lol: 

Bruce Tai is a professional of some serious standing, has the opportunity and ability to carry experimental work none of us could dream about and has been kind enough to share with us his results and his interpretation of those. I for one am very grateful and so are others. Nagyvary might've exaggerated his claims but his research was surely competently carried out and definitely light years ahead of negative rants from unknown quantities on ...... MN. Same for Barlow, Echard and Brandmair . All have done and are doing incredibly valuable work given the exceptional restrictions this field places on the actual subject of said research.   

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