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Curious about this finish


MikeC
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So I decided to browse youtube and came across this video by Andreas Preuss.   At 1:30 into the video there is an incredibly black substance on the maple back plate and then you see him wipe a bit of some powder on it and start rubbing.    Have you ever seen anything like that?  What could it be?   Looks like soot or something?  Black mystery stain?  Surely that would burn / lock the flame?      

 

Did Strad have a stream and water wheel in the courtyard of his rented townhouse/shop ?  

 

 

 

 

Edit,  almost said something rude about Facebook,  Rube Goldberg power tools and a lack of science in the 18th C.  but decided not to.    (no water powered sawsall?)

Edited by MikeC
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yeah,  it does kind of look like that.  That's why I wondered if it's soot or something.    I wonder what Preuss's fiddle looked like after it was finished.  I didn't see that.   Actually,  I found a link with some more pictures.  Some of it looks pretty good. 

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probably so.  He talks about alchemy and the use of water.   But didn't Strad live in a rented town house?   I don't think he had a stream and water wheel in his courtyard or did he?    It reminds me of a Rube Goldberg thing.  Make something really complicated when a simple hand tool will do.

Also regarding a lack of science in the 18th C.    Newton invented calculus in the mid 1600s.  They were not exactly a bunch of rubes. 

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Guitar manufactures use a black gel stain to accentuate the figure in wood. Carvin calls it the "deep triple step finish" you may be able to find examples in some of their factory tour video.

The gel does not penetrate very much and then its sanded away, leaving remants in the flame.

 

Some examples of with and without the stain.

post-29938-0-20704200-1435331953_thumb.jpg

post-29938-0-72948000-1435331985_thumb.jpg

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My take on the black color mentioned in the initial post of this thread is that it is a surface result of some kind of water immersion treatment. To my eye it appears that the maker is applying some kind of tripoli type abrasive rub to the surface of the wood to remove this black coloration. The rest of the wood shown in the video has a grey coloration which I would associate with some kind of water immersion especially given that Mr Preuss mentions water immersion. Interesting video of a fine and  interesting luthier..,lots of thought provoking stuff to see there.

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Thanks for pointing that out Melvin,

This is wood that I ponded (top) for about three months in the cool of my basement . looks about the same.

I choose my least desirable set of red maple to try it on .   it's easy to see a large amount of movement in the wild grain , I might feel more like using it now , with less fear of warpage in the finished instrument .

 

post-30189-0-61858300-1435343725_thumb.jpg

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In that scene it does appear quite wet where he is wiping it with the cloth.    But wouldn't water emersion cause the center seam to come appart?   It doesn't look like there is any purfling in the maple at this point in the process.  

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I bought something called "extrato de nogueira" at a local cabinet makers shop, i think the translation would be something like "tung extract"

Composition: mineral, fossil and organic substracts, minerals, carbonate, magnesium, sodium hidroxide and silica. Non toxic. (traslation can be wrong, sorry)

It says that it is soluble in water, and its uses are: Wood stain, Wood figure enhancer and pore filler.

I made a water based solution with it and rubbed in this non figured maple i have:

 

CCcsS5e.jpg

 

The black pieces are the "tung extract", the black dye is the solution, and the maple you see is after aplied and sanded.

I think it looks a lot like what Preuss used, and it really enhances the figure, but it kind of kills the chatoyance.

I dont have any good figured maple to test it on unfortunately

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Lung extract  oh my!  In that picture it looks like it fills the pores and grain.  It doesn't look very transparent so I can understand that it would kill the chatoyance.  

 

In the Preuss video I slowed it down and looked at it frame by frame.  It's clear the wood is wet (shiny) initially and then he dries it off with the white cloth. Then he puts a smear of pink colored powder and begins rubbing it with something that looks like a piece of horsetail grass.  So I think the powder may be an abrasive rather than a pore filler. 

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Lung extract...my 2nd oldest brother lungs no doubt must look like this. It's interesting and I have to wonder where they harvest this. Never heard of it. Have you Mike?

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TUNG extract ...

   I have no idea what the paste is ,"hard tellin ...not knowin" 

could be volcanic ash or a Melvin suggested some sort of Tripoli . might be smoothing and filling at the same time ..? the water wetting ( assuming it was water) could help with packing the pores. I noticed he also mentioned 7 steps , perhaps he was not telling the hole story...

I think his whole point was that we a modern luthiers might find some advantage to look a bit beyond purely scientific means, if we want to recreate Strad methods entirely . I have no idea if  he's correct about Strads ponding, whether he did it or not .. I can say the wood that I did has fantastic chatoyance under varnish. And judging by the amount of movement or warping , there was considerable amount of internal stress relief. something that could have acoustic impact beyond simple SG and strength to weight ratios . "hard tellin ..not knowin"

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My take on the black color mentioned in the initial post of this thread is that it is a surface result of some kind of water immersion treatment. To my eye it appears that the maker is applying some kind of tripoli type abrasive rub to the surface of the wood to remove this black coloration. The rest of the wood shown in the video has a grey coloration which I would associate with some kind of water immersion especially given that Mr Preuss mentions water immersion. Interesting video of a fine and  interesting luthier..,lots of thought provoking stuff to see there.

We agree - lots of food for thought. I too immediately thought the pink materials was tripoli. I thought the black paste was asphaltum, but I have doubts about that initial idea. I now think it is wood ash.

 

I totally agree with the alchemist idea. That is something worth pursuing.

 

BTW, take a look a Joe Robson's page on his web site:

 

http://www.violinvarnish.com/

 

 

 

Mike

Edited by Michael_Molnar
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  • 5 years later...

Digging up an old thread here.  I was reading a paper on mineral analysis of Cremona instrument wood and found this quote

 One cannot rule out the possibility that an alcoholic solution of chimney soot was also applied to the wood, this having been the practice of the last great Cremona trained violin-maker, G.B. Guadagnini [23].

So did Guadagnini really use chimney soot?   It reminded me of this old video by Andreas Preuss with the very dark black wood.  

Here is the reference citation

23. Dipper A, Woodrow D. Count Cozio di Salabue: Observations on the Construction of String Instruments and Their Adjustment. Translated from Italian with commentaries. Trowbridge, Wiltshire, England: 1st edition, published by Redwood Burn Ltd; 1987. p. 64. [Google Scholar]

Here's a link to the article 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2621340/

 

 

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9 minutes ago, MikeC said:

So did Guadagnini really use chimney soot?   It reminded me of this old video by Andreas Preuss with the very dark black wood.  

 

(Eyebrows raised, looks up and to the right....) so, there’s this “art” thing I do with found wood. I burn it with a butane torch and burnish it with river rock and linseed oil. I’ve found that, on some wood, it changes the harmonic resonance of the wood from a clunk to more of a chime. Maple showed a large change. As does Madrone and of all things, Lavender.   It’s all very unscientific but there is a very clear and delightful audible change.  What if... a  violin being built had this treatment to the back, prior to final assembly... Just throwing it out there for the more adventurous and those with a great deal of time (or OCD) to spend running a rock back and forth. 

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15 minutes ago, Mystic said:

(Eyebrows raised, looks up and to the right....) so, there’s this “art” thing I do with found wood. I burn it with a butane torch and burnish it with river rock and linseed oil. I’ve found that, on some wood, it changes the harmonic resonance of the wood from a clunk to more of a chime. Maple showed a large change. As does Madrone and of all things, Lavender.   It’s all very unscientific but there is a very clear and delightful audible change.  What if... a  violin being built had this treatment to the back, prior to final assembly... Just throwing it out there for the more adventurous and those with a great deal of time (or OCD) to spend running a rock back and forth. 

Well I had some real wood charcoal that had a nice ring to it when tapped but of course you can't build a fiddle out of charcoal.  Don Noon partially carbonizes his wood though heating in the absence of oxygen.  Personally I wouldn't do that.  

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7 hours ago, MikeC said:

Digging up an old thread here.  I was reading a paper on mineral analysis of Cremona instrument wood and found this quote

 One cannot rule out the possibility that an alcoholic solution of chimney soot was also applied to the wood, this having been the practice of the last great Cremona trained violin-maker, G.B. Guadagnini [23].

As far as I am aware there is no solid evidence that G.B. Guadagnini was trained in Cremona

 

7 hours ago, MikeC said:

Here is the reference citation

23. Dipper A, Woodrow D. Count Cozio di Salabue: Observations on the Construction of String Instruments and Their Adjustment. Translated from Italian with commentaries. Trowbridge, Wiltshire, England: 1st edition, published by Redwood Burn Ltd; 1987. p. 64. [Google Scholar]

This is a reference to the Mantegazzas using a dye extracted from fuligine, which (apparently) they applied after having sized the wood with glue

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1 hour ago, plasterercaster said:

As far as I am aware there is no solid evidence that G.B. Guadagnini was trained in Cremona

 

This is a reference to the Mantegazzas using a dye extracted from fuligine, which (apparently) they applied after having sized the wood with glue

I don't know much about Guadagnini just a little from the wikipedia article on him.  That he was born 30 kilometers from Cremona and his father was a contributing maker of instruments for Stradivari's workshop, whatever that means.  

 Maybe the authors of the paper got it wrong but I thought it was interesting the quote about using chimney soot.  

a little more searching and.. 

soot dye guadagnini.PNG

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