Danube Fiddler

The ground ( sealing) of the great masters - which was it ?

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15 minutes ago, Michael Darnton said:

The oil in the pan was raw oil from the art store. Art restoration books talk about linseed oil going through such changes that the age of the oil can be determined over a period of time reaching 600 years. In some of those phases, the oil varies through alcohol solubility and also insolubility, and returns to near liquid at some points. I think, then, that any casual statements about such characteristics (particularly the alcohol solubility characteristics commonly mentioned here as "proof" of oil vs spirit varnish*) may be dangerously unproven.

All I know about this issue is that back in the Victorian era, one eccentric had the mistaken theory that Stradivari used spirit varnish on his violins, and he "proved" it by demonstrating that alcohol could dissolve the varnish on a Stradivarius.

Now, we know that linseed oil, while not soluble in alcohol, unlike spirit varnish, when initially applied, undergoes changes with time, and can dissolve in alcohol when 300 years old or so.

So I thought this controversy was completely settled at the present time.

As for generalizations, I do tend to accept the notion linseed oil good, spirit varnish bad. When Guadagnini used spirit varnish, his violins weren't as good, they say. And spirit varnish tends to soak into the wood more, stiffening it, than linseed oil - even the latter soaks to some extent, so you need a ground coat, but spirit varnish tends to soak through ground coats.

This is based on what I have encountered in my reading that seemed like sensible advice, corroborated by the more credible writers. It could be that even that, though, is too oversimplified: but I hope the situation is not so complicated that it is not possible to derive any useful general rules as a guide to good practice.

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9 minutes ago, Quadibloc said:

 

As for generalizations, I do tend to accept the notion linseed oil good, spirit varnish bad. 

See: you are doing exactly what I warned against, because this has been proven incorrect over and over again. This is precisely the problem: you responded to my post by providing myths you have no personal experience about.

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26 minutes ago, Quadibloc said:

Now, we know that linseed oil, while not soluble in alcohol, unlike spirit varnish, when initially applied, undergoes changes with time, and can dissolve in alcohol when 300 years old or so.

If you try to dissolve raw linseed oil in alcohol you will fail in a high degree. If you try to dissolve linseed-oil in a mastix-spirit-solution, you will succeed immediately, not only after 300 years. I assume the same for colophon.

So I don´t believe in this old test to separate spirit and oil-varnish.

Additional : If there should be an oil - ground, I assume, that a later applied spirit varnish will not remain a spirit - varnish but will mix togehter with soluted oil of the ground and resulting in an oil-varnish. If this happens, could highly depend on the used resins in the spirit varnish.

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One can speculate.  One can observe.

I observe a ground treatment that:

Illuminates the wood structure to a degree that is stronger than the tinting power of the varnish.  This details varies with the kind and intensity of the light used.

Reveals all details of the wood, even at great age,with or without the protection of the varnish.

Does not fill the pore/grain structure.

Dents before it fractures when struck.

Is extremely protective from almost all environmental factors and organic solvents,even at great age.

on we go,

Joe

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25 minutes ago, joerobson said:

One can speculate.  One can observe.

I observe a ground treatment that:

Reveals all details of the wood, even at great age,with or without the protection of the varnish.

Does not fill the pore/grain structure.

Dents before it fractures when struck.

Is extremely protective from almost all environmental factors and organic solvents,even at great age.

on we go,

Joe

If the observed ground treatment didn´t fill the pores and grain-structure (= cell cavities or at least vessels ? ), what then finally will be in the pores ? Coloured varnish ? 

What you could have observed ?

not soluble in almost all organic solvents ---->  not a resin      /     not a wax

resistant to nearly all environmental factors ( also humidity or water ) -----> not a protein or one of the few not water-soluble ones ( after application) like casein or a highly alum-treatet glue ( which keeps in my experience water sensitive ) However all these proteins in a dry condition would no dent, isn´t it.

-----> not a protein 

What remains ?

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14 minutes ago, Danube Fiddler said:

If the observed ground treatment didn´t fill the pores and grain-structure (= cell cavities or at least vessels ? ), what then finally will be in the pores ? Coloured varnish ? 

What you could have observed ?

not soluble in almost all organic solvents ---->  not a resin      /     not a wax

resistant to nearly all environmental factors ( also humidity or water ) -----> not a protein or one of the few not water-soluble ones ( after application) like casein or a highly alum-treatet glue ( which keeps in my experience water sensitive ) However all these proteins in a dry condition would no dent, isn´t it.

-----> not a protein 

What remains ?

it was my impression that Joe meant that nothing was in the pores, so just air? which would mean the ground lays practically on top of the wood....

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1 minute ago, Emilg said:

it was my impression that Joe meant that nothing was in the pores, so just air? which would mean the ground lays practically on top of the wood....

In the wood, not on the wood. 

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1 minute ago, Danube Fiddler said:

May I repeat my question : What will finally be in the pores ? Your observed ground apparently does not.

As the varnish follows the geography of the wood, what is observed from the surface will depend on the structure of the wood.

pores.jpg

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What Joe's photo shows is "ventilation ducts" of unsealed pores coming through to the varnish surface and something that is very commonly seen on the later Cremonese violins with particularly beautiful varnish. I think I've seen it most often on Carlo Bergonzi's violins.

Here's a GB Guad from his Piacenza period:

Guad-pinholes.jpg

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47 minutes ago, Michael Darnton said:

What Joe's photo shows is "ventilation ducts" of unsealed pores coming through to the varnish surface and something that is very commonly seen on the later Cremonese violins with particularly beautiful varnish. I think I've seen it most often on Carlo Bergonzi's violins.

Here's a GB Guad from his Piacenza period:

Guad-pinholes.jpg

Thank you for the photo Michael.  Excellent detail of the Ground and transitions to varnish.

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1 hour ago, joerobson said:

As the varnish follows the geography of the wood, what is observed from the surface will depend on the structure of the wood.

pores.jpg

So, in the pores at first will be air, at least in the deeper ones, because the quite high-viscous oil - varnish can´t displace the air so fast. However later this will be done, resulting in a pore-filling just by varnish. 

I think the primary treatment should be quite unimportant for sound, because this should be a very small amount of materia, whatever it is. Any procedure should be equal, which preserves against a very deep penetrating.    As Brandmeir reports, a mediocre penetration ( 2/10 mm) was not avoided by the ancient primary ground.

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2 hours ago, joerobson said:

One can speculate.  One can observe.

I observe a ground treatment that:

Illuminates the wood structure to a degree that is stronger than the tinting power of the varnish.  This details varies with the kind and intensity of the light used.

Reveals all details of the wood, even at great age,with or without the protection of the varnish.

Does not fill the pore/grain structure.

Dents before it fractures when struck.

Is extremely protective from almost all environmental factors and organic solvents,even at great age.

on we go,

Joe

Sounds like some kind of oil.

WW

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2 minutes ago, JacksonMaberry said:

Hallelujah

Why "Hallelujah " ?    Is it not very naturally, that a ground or sealer has to be in the wood ? 

However I believe to understand, what Joe means : This pre-treatment should be something, which closes only the smallest passages in the wood. Eventually a watersoluble material, fastly getting high-viscous, when the wood absorbes water from the solution. Could glues be such a material ?

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19 minutes ago, Danube Fiddler said:

  Is it not very naturally, that a ground or sealer has to be in the wood ? 

No, not at all. Many approaches lay a film down on top of the wood surface and penetrate little if at all into the wood surface. 

Also I think you're misinterpreting Joe's posts. I'll leave it to him to clarify as he sees fit. 

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10 minutes ago, JacksonMaberry said:

No, not at all. Many approaches lay a film down on top of the wood surface and penetrate little if at all into the wood surface. 

Also I think you're misinterpreting Joe's posts. I'll leave it to him to clarify as he sees fit. 

I will wait for it.

Another idea :   Possibly the pre-treatment was a material, which didn´t close any smallest passages, but did alterate the adhesion of a later applied varnish or oil-treatment to the wood and therefore reduced the capillary - action of this second application so much, that the varnish/cooked oil/ raw oil couldn´t penetrate the wood in a normal degree but only very little.

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8 hours ago, Michael Darnton said:

http://darntonviolins.com/tag/linseed-oil/
The oil in the pan was raw oil from the art store. Art restoration books talk about linseed oil going through such changes that the age of the oil can be determined over a period of time reaching 600 years. In some of those phases, the oil varies through alcohol solubility and also insolubility, and returns to near liquid at some points. I think, then, that any casual statements about such characteristics (particularly the alcohol solubility characteristics commonly mentioned here as "proof" of oil vs spirit varnish*) may be dangerously unproven.

I have experimented with oil quite a bit this side of those examples. Oil did not appear to affect the sound too much compared with my violins with no oil. There are a lot of ways to put oil on. It is possible, for instance, totally seal a violin with less than 5 (measured) drops of oil, counting what gets left on the applicator! I don't see how this could have any tonal effect worth talking about, and it has not, for me. In the 70s there was talk about the possibility of sealing violins by rubbing a walnut meat over the wood to leave a layer of walnut oil. I never tried that, but that would be similar. Using this type of oil coating, it's important--crucial--to let the first coat dry completely before the second, and the second again before varnishing, or the subsequent coat will just pick up the previous and carry it along inside, rather than it acting as an insoluble sealing layer. I'd say a week in the light box is a bare minimum, by real experience.

* [Bill Fulton, the varnish experimenter, mentioned somewhere a test he had performed aging oil varnish in the sun on the dashboard of his car. He commented that initially, after curing for a couple of months, it was not alcohol soluble, but that some years later it became soluble again. This is my experience, also]

 

My experience with oil aging is the same as Michael's, it never gets hard and so it is not advisable to deeply impregnate wood with it, a substance that hardens completely would be more advisable for me. However if you use it appropriately in an extremely thin layer as Michael describes it does not cause acoustic problems, even if I have never tried to do it.  Here is how looks like and behave the polymerized linseed oil and naturally oxidized in air for a long period of time :

 

After the initial oil polymerization, it takes at least five or six years of natural oxidation to complete the process of transformation and make it completely soluble in alcohol. This is thirty years old (polymerization process started in 1986 year) and it is transformed into a stable substance, very plastic and not hard at all. In ethyl alcohol  it dissolves completely in a few minutes.

 

 

 

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This might be of interest from a 1900 Strad magazine.  Wonder how that Whitlaw varnish worked out over time--but it is the finest varnish in the world.   I bet there is a lesson in this.

Mike D

 

image of page 22

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Back to what G&G and Echard found. 

Wouldn't a short (perhaps very short) oil varnish satisfy the criteria that Joe and others have observed, as well as result in what our scientists have seen in the wood, namely oil and resin? No reason to believe the oil and the resin aren't cooked together, no? 

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7 minutes ago, JacksonMaberry said:

Back to what G&G and Echard found.  Wouldn't a short (perhaps very short) oil varnish satisfy the criteria that Joe and others have observed, as well as result in what our scientists have seen in the wood, namely oil and resin?

This is, what I assume - even if you should use only a quite high-viscous cooked oil. 

Brandmeir found a proteinous pretreatment in the first wood-cell-rows. That´s all, what she found or could detect below the oil-varnish-filling of the pores.  The protinous material apparently mostly didn´t fill but in the Guadagninis it had also coloured the filling material in a lot of cell-cavities of the first cell-rows.

The amount of this first-application-substance is so small, that I can´t imagine any direct acoustical benefits.

Do you know, why many makers do use a proteinous pre-treatment also in our days. Nobody could explain me until now, which function it exactly has. In my own experiments it could not seal an end-grain-surface against spirit-varnish at all, even if I applied it very strong. I assume because of producing a lot of micro-cracks while drying and contracting. Nearly all attempts to close the surface by using other materials did suceed much more !

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1 hour ago, Davide Sora said:

My experience with oil aging is the same as Michael's, it never gets hard and so it is not advisable to deeply impregnate wood with it, a substance that hardens completely would be more advisable for me. However if you use it appropriately in an extremely thin layer as Michael describes it does not cause acoustic problems, even if I have never tried to do it.  Here is how looks like and behave the polymerized linseed oil and naturally oxidized in air for a long period of time :

 

After the initial oil polymerization, it takes at least five or six years of natural oxidation to complete the process of transformation and make it completely soluble in alcohol. This is thirty years old (polymerization process started in 1986 year) and it is transformed into a stable substance, very plastic and not hard at all. In ethyl alcohol  it dissolves completely in a few minutes.

 

 

 

Quite impressing !

Does this linoxyn still stick ? 

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