what does ossify mean?

[Carl Stross]

Sodium silicate is available in both alkaline and neutral.

A chemist would be nice just about now...

[captainhook]

Sodium silicate is available in both alkaline and neutral.

Hmm. Don't know about that. Sodium silicate is the salt of a strong base and a weak acid, so it is always going to be alkaline. That doesn't mean it is strongly alkaline, as lye is, it is still a salt after all. But solutions of it usually do contain a little bit of lye.

The relevant wood chemistry gets a little more complex than I want to get into at the moment. Stuff I learned making cellophane and paper over 33 years. I find benefits to using waterglass on wood but it helps to be a chemist.

[scordatura]

On a less than scientific hunch, I feel that there is something to the acoustic properties of the sealer (the first contact with the wood). Not only the composition but the method of application. I have found that Sacconi's, Peresson's and Zigs clues reguarding this to be thought provoking.

[MikeC]

I posted two threads, this one and also one where I asked the meaning of 'refractive' ground. I know the usual meaning of refractive and ossify but not in the context of violin wood. What prompted me to ask is that I have something that I applied to some curly maple that really brings out the 3D depth of the flame. I haven't tried it on a sample of spruce since I don't have any. I was wondering how it compares to the classic Cremona ground since it is the best first contact substance I've seen so far. After reading Joe's information on his balsam ground I think it is something similar to that. Not a silicate.

I'm not familiar with Peresson. I'll have to google that name.

In all the analysis of Cremona instruments has anyone found any evidence of silicates or mineralization? And I don't mean the electron micrographs. The ones showing a granular texture which everyone automatically assumes is mineral, and a ridiculously thin layer of supposedly varnish.

[Bill Yacey]

The answers to your questions are all dependent upon who you ask. As I'm sure you are aware there are essentially two camps, the mineralists and the minimalists. From my perspective, I haven't seen anything other than "Take our word for it; it's there" from the mineralists, and yet no irrefutable evidence. The minimalists aren't really looking for something that they presuppose isn't there, so they simply argue against the claims of the mineralists. Recent studies indicate a protein ground.

This would be the prerequisite makings for a bar room brawl if they were all in the same room drinking together.

[JimMurphy]

The answers to your questions are all dependent upon who you ask. As I'm sure you are aware there are essentially two camps, the mineralists and the minimalists.

And then there are the 'compromisers' who may be mineralists for Maple and minimalists for Spruce.

Jim

[scordatura]

Sergio Peresson was an interesting maker. Much sought after in the 70s and 80s. His fame was secured when Jacqueline DuPre used one of his cellos. Eugene Fodor was another proponent. Many of the Philadelphia Orchestra members at least at one time used his instruments. The better instruments have good volume and projection.

In model and approach he evolved into a maker that took a left turn. Worked for Moennig. Some became critical of him after the demand went up. His fiddles go for a decent amount.

[David Burgess]

If one wants to experiment with potassium silicate, Rubios information might be a good starting point. He reacts it with minerals in a way which supposedly leaves it insoluble and ph neutral.

http://www.rubioviolins.com/

Click on "Mineral Ground recipe & research"

Sodium and potassium silicates have been used as a concrete sealer and hardener, and are said to react with free calcium in the concrete to become stable and waterproof. Attempts to use it in fresco painting (based on the same reaction?) haven't worked out too well though.

Getting back to an earlier question, Strad wood splits and exhibits grain direction like any other wood, in my limited experience. Though sometimes you get this "punky" wood in old fiddles (including some Strads), which is a little different, which I've guessed was due to degradation from moisture/micro-organisms. Is there a mention of less evident grain direction in the Sacconi book? The only mention popping into my head right now was from Bill Fulton, referring to properties of ammonia fumigated wood.

If it's mentioned in the Sacconi book though, I generally trust his observations (if not always his interpretations), and he would have done way more cutting on Strads than I have. Perhaps it's subtle enough not to notice without having done a lot of cutting?

[NewNewbie]

The Strad July 2011 has an article by Koen Padding of Magister Varnish Products and in it he points out that Sacconi was getting information from Louis Condax, and this lead to some of his ideas.

"Sacconi on varnsih

Simone Sacconi’s ideas about Stradivari’s varnish relied as much on hypothesis as hard evidence, and led to recipes that were largely impractical. But as Koen Padding explains, Sacconi’s concept stacks up well against the latest scientific analysis" - July 2011 The Strad

I think the question that he, Sacconi, raises about Stradivari's instruments surviving shipwrecks lead him to think that the ground coating was responsible for this durability, and thus his use of the term 'ossification'.

If you did not get the July issue, there is a "Publications Section" at Koen Padding's site which should hopefully one day have a download-able copy of the article.

[scordatura]

I was just rereading some of the Curtain/Alf stuff about their approach. They mention fuming with ammonia for 15-20 min.

I have the Condax research somewhere. I am going to dig it up.

[scordatura]

And then there are the 'compromisers' who may be mineralists for Maple and minimalists for Spruce.

Jim

I would think the opposite would be more effective.

[JimMurphy]

I would think the opposite would be more effective.

And yet Echard's recent study claims no mineral ground was found [allegedly] on Spruce.

Jim

[Janito]

The paper contains some interesting facts:

- proteins are easily degraded by alkaline hydrolysis (I knew this)

- large carbohydrates like cellulose are very resistant (I did not know this - I expected the same behaviour as glycogen and starch which are easily broken down).

The differential effect of alkaline hydrolysis on cellulose and other polymeric carbohydrates such as starch has had me thinking...

(i) Could it be that there are 'chemical' ways of accelerating the loss hemicelloluse, while preserving the structural cellulose?

(ii) Is it possible that the beneficial effects of silicates have nothing to do with ossification, but instead are due to the removal of hemicellulose and other disadvantageous materials in the wood?

This is from the Wikipedia article on hemicellulose:

A hemicellulose is any of several heteropolymers (matrix polysaccharides), such as arabinoxylans, present along with cellulose in almost all plant cell walls. While cellulose is crystalline, strong, and resistant to hydrolysis, hemicellulose has a random, amorphous structure with little strength. It is easily hydrolyzed by dilute acid or base as well as myriad hemicellulase enzymes.

[scordatura]

And yet Echard's recent study claims no mineral ground was found [allegedly] on Spruce.

Jim

Depending on the sample(s) used there seems to be some inconsistencies in the various studies. The recent strad article did point out basic agreement between the three systems outlined.

[Don Noon]

(i) Could it be that there are 'chemical' ways of accelerating the loss hemicelloluse, while preserving the structural cellulose?

The only ways I am aware of are thermal, fungus, and enzyme treatments. I have experimented with other acids and alkalis, none of which did anything good.

((ii) Is it possible that the beneficial effects of silicates have nothing to do with ossification, but instead are due to the removal of hemicellulose and other disadvantageous materials in the wood?

"beneficial effects" have not been evident in my tests, or with many others who have tried it. But let's say there are. If it's only a very thin surface treatment, then the removal of hemicellulose wouldn't do much, and even less if it is only the outside surface of the instrument. Adding a thin high-performance layer would seem to be much more effective than removing a portion of less-good stuff.

[GlennYorkPA]

If one wants to experiment with potassium silicate, Rubios information might be a good starting point. He reacts it with minerals in a way which supposedly leaves it insoluble and ph neutral.

http://www.rubioviolins.com/

Click on "Mineral Ground recipe & research"

Sodium and potassium silicates have been used as a concrete sealer and hardener, and are said to react with free calcium in the concrete to become stable and waterproof. Attempts to use it in fresco painting (based on the same reaction?) haven't worked out too well though.

Getting back to an earlier question, Strad wood splits and exhibits grain direction like any other wood, in my limited experience. Though sometimes you get this "punky" wood in old fiddles (including some Strads), which is a little different, which I've guessed was due to degradation from moisture/micro-organisms. Is there a mention of less evident grain direction in the Sacconi book? The only mention popping into my head right now was from Bill Fulton, referring to properties of ammonia fumigated wood.

If it's mentioned in the Sacconi book though, I generally trust his observations (if not always his interpretations), and he would have done way more cutting on Strads than I have. Perhaps it's subtle enough not to notice without having done a lot of cutting?

David,

Unfortunately, my copy of Sacconi is in Italian so it's taking me a while to work through it again but he makes some quite specific assertions regarding Strad's wood preparation.

He says something was used to harden the soft portions of the wood (summer growth). It was absorbed into the soft wood but not into the harder parts, This process of hardening, 'let's call it ossification', as if by crystalization, confers on the wood a greater capacity to vibrate. He goes on the say that this allows the wood to be carved much thinner to a final thickness that would not be possible without the ossification treatment.

Later, on p164, he asserts that chemical analysis indicates a notable quantity of silica and potassium leaving no doubt that silicate of potassium and calcium was used.

He says it should be diluted to watery consistency (as Lyndon has said) . It should be allowed to penetrate the wood. After the treatment, the wood becomes rough and should be smoothed with fine fish skin.

In summary, he seems to be making the following assertiones:

1. Strad gave the wood a treatment which ossified the wood making it impervious to sweat, dirt and abrasive wear.

2. This treatment enabled the wood, especially the top, to be thinned to a greater degree than would have been possible with untreated wood.

3. That the treatment was undoubtedly diluted water glass as used for preserving eggs.

He doesn't say that the treatment prevents the wood from splitting.

Glenn

[Bill Yacey]

1)

I don't understand the logic of protecting the wood from sweat dirt and abrasive wear when the varnish fulfills this purpose until the varnish wears away entirely. Did Strad realize beforehand his varnish would fail quickly and took extra precautions? In my mind, this is kind of like wondering how durable the underlying primer will be on a motor vehicle long after all the paint peels off.

Maybe this is just modern mentality, but did the Cremonese really care how well the instruments would stand up to the vestiges of time if they could instead sell another replacement instrument when the original one failed after a number of decades of use?

2.)

If Strad and the other Cremonese makers employed this treatment to the wood with the goal of the ability to work the wood thinner, why have so many of these violins been regraduated through history, if they were already worked thinner by the makers compared to using using conventional non-treated wood? Yet contrary to this idea, many of the old instruments appear originally to have been made quite thick by modern standards.

3)

If Brandmair's study is accurate, she apparently didn't find any quantities of silica beyond what naturally occurs in the wood.

Sacconi's observations seem to create more conflicting data than what it answers. I can understand in his era he didn't have available many of technological advances we now have access to, but there may still be some partial truths to what he observed.

[David Burgess]

He says something was used to harden the soft portions of the wood (summer growth). It was absorbed into the soft wood but not into the harder parts, This process of hardening, 'let's call it ossification', as if by crystalization, confers on the wood a greater capacity to vibrate. He goes on the say that this allows the wood to be carved much thinner to a final thickness that would not be possible without the ossification treatment.

Later, on p164, he asserts that chemical analysis indicates a notable quantity of silica and potassium leaving no doubt that silicate of potassium and calcium was used.

He says it should be diluted to watery consistency (as Lyndon has said) . It should be allowed to penetrate the wood. After the treatment, the wood becomes rough and should be smoothed with fine fish skin.

In summary, he seems to be making the following assertiones:

1. Strad gave the wood a treatment which ossified the wood making it impervious to sweat, dirt and abrasive wear.

2. This treatment enabled the wood, especially the top, to be thinned to a greater degree than would have been possible with untreated wood.

3. That the treatment was undoubtedly diluted water glass as used for preserving eggs.

It's widely agreed that there is something under the colored varnish which is quite resistant to wear, perspiration and dirt, at least on most of the instruments. The disagreement is over what it is. Fine particulate matter in some medium was one explanation which could have accounted for silica and potassium content, but now that's been called into question too.

As I mentioned before, I tend to trust Sacconi's observations. It's his conclusions, like when he tried to weave his observations into a specific varnishing system, that might be weak.

[MikeC]

It's widely agreed that there is something under the colored varnish which is quite resistant to wear, perspiration and dirt, at least on most of the instruments. The disagreement is over what it is. Fine particulate matter in some medium was one explanation which could have accounted for silica and potassium content, but now that's been called into question too.

As I mentioned before, I tend to trust Sacconi's observations. It's his conclusions, like when he tried to weave his observations into a specific varnishing system, that might be weak.

David, when you say something under the colored varnish, is that something impregnated into the wood with no surface thickness? Or does it have some thickness over the wood surface?

[Carl Stross]

David, when you say something under the colored varnish, is that something impregnated into the wood with no surface thickness? Or does it have some thickness over the wood surface?

It has SOME thickness, it floats on the wood but also impregnates. ( That's provided I'm not looking in the wrong spot ). To my eye is another varnish.

[MikeC]

It has SOME thickness, it floats on the wood but also impregnates. ( That's provided I'm not looking in the wrong spot ). To my eye is another varnish.

So all who have had first hand observation would agree with this? That is has 'some' surface thickness? What other characteristics does it have? color? how thick? I assume fairly thin? Thinner than the colored varnish layer? And harder? Is it hard as in brittle? like rosin? or just tough as in wear resistant?

[NewNewbie]

And yet Echard's recent study claims no mineral ground was found [allegedly] on Spruce.

Jim

Do you really think that Echard and the rest of the investigators forgot to look at the maple parts?

Picture link

Alleged picture of Echard.

[NewNewbie]

Later, on p164, he asserts that chemical analysis indicates a notable quantity of silica and potassium leaving no doubt that silicate of potassium and calcium was used.

Glenn

So if chemical analysis indicated "a notable quantity of silica and potassium" how did the calcium sneak in there?

[NewNewbie]

1)

I don't understand the logic of protecting the wood from sweat dirt and abrasive wear when the varnish fulfills this purpose until the varnish wears away entirely. Did Strad realize beforehand his varnish would fail quickly and took extra precautions? In my mind, this is kind of like wondering how durable the underlying primer will be on a motor vehicle long after all the paint peels off.

Maybe this is just modern mentality, but did the Cremonese really care how well the instruments would stand up to the vestiges of time if they could instead sell another replacement instrument when the original one failed after a number of decades of use?

If you read up on how art work was handled during this time period, you might see their approach/attitude that they had towards final coatings.

2.)

If Strad and the other Cremonese makers employed this treatment to the wood with the goal of the ability to work the wood thinner, why have so many of these violins been regraduated through history, if they were already worked thinner by the makers compared to using using conventional non-treated wood? Yet contrary to this idea, many of the old instruments appear originally to have been made quite thick by modern standards.

They have also had wood added to them as well, but who is to say that everything done to them was beneficial.

3)

If Brandmair's study is accurate, she apparently didn't find any quantities of silica beyond what naturally occurs in the wood.

Maybe she didn't look at the maple parts???? :blink: :blink:

Sorry couldn't resist a laugh.

See post # 47.

If you are a slave to a rigid formula, then not having a mineral ground does seem to be breaking the rules.

That would then beg the question of why do we see so much variation in just one makers work?

Surely a rigid set of rules doesn't produce variation.

If however they were free to use judgement, then perhaps each violin was seen as; and treated as; an individual unique challenge, and handled according to the judgment of the maker.

This would help to explain why violins seem to defy 'mass production'.

Sacconi's observations seem to create more conflicting data than what it answers. I can understand in his era he didn't have available many of technological advances we now have access to, but there may still be some partial truths to what he observed.

Have you read the article in the July issue of The Strad 2011 titled "A Fresh Look at Sacconi's Varnish Research" by Koen Padding of Magister Varnish Products?

See post # 34 in this thread for links.

[NewNewbie]

So all who have had first hand observation would agree with this? That is has 'some' surface thickness? What other characteristics does it have? color? how thick? I assume fairly thin? Thinner than the colored varnish layer? And harder? Is it hard as in brittle? like rosin? or just tough as in wear resistant?

'Yes' along with some 'No' thrown in for good measure 'Plus or Minus' and a 'Maybe So' or two, 'Give or Take', if you catch my drift, nudge nudge, wink wink, you know what I mean .... huh?

Of course I may get an argument from some, but I am totally ready to abandon my position at a moments notice.

You are asking the $64,000.00 question!