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what does ossify mean?


MikeC
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Yes but I believe Ozzie would have said the same thing had he been asked about Elvis... :D

I don't think you can safely be the leader of Black sabbath and keep a very clear mind for 40 years.

Having said that I had been fortunate enough that I had never heard about J. Bieber until 1 or 2 months ago when the kid banged his head into a revolving glass door. So I thought he was a young comic actor in the making.

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What other characteristics does the unicorn of a Cremona ground layer have? Seems like I've read descriptions like 'reflective'? 'sparkling'?

One of the biggest chores dealing with anything having to do with authentic Cremonese varnish descriptions, is the gaining an ability to strip away the various "romantic" descriptions and hyperbole.

If one was to list all of the miraculous attributes given to this varnish, they would rival the Bibles depiction of heaven itself.

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Perhaps one of the biggest chores dealing with anything having to do with authentic Cremonese varnish descriptions, is the gaining an ability to strip away the various "romantic" descriptions and hyperbole.

If one was to list all of the miraculous attributes given to this varnish, they would rival the Bibles depiction of heaven itself.

That is the voice of wisdom.

Reading again Echard et al work conclusions.

So lots of italian sun and a natural yellow/golden brown wood, a little bit of linseed/drying oil first, then a colored oil/resin varnish (iron oxyde/vermillon, cochineal or madder lake depending of the mood of the day) and voila!... :)

This sounds so simple even I should be able to do it :D

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That is the voice of wisdom.

Reading again Echard et al work conclusions.

So lots of italian sun and a natural yellow/golden brown wood, a little bit of linseed/drying oil first, then a colored oil/resin varnish (iron oxyde/vermillon, cochineal or madder lake depending of the mood of the day) and voila!... :)

This sounds so simple even I should be able to do it :D

so simple even a caveman could do it :lol:

So they DID find linseed at the wood surface? Was it definately identified as linseed? or could it have been something else?

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Reading again Echard et al work conclusions.

So lots of italian sun and a natural yellow/golden brown wood, a little bit of linseed/drying oil first, then a colored oil/resin varnish (iron oxyde/vermillon, cochineal or madder lake depending of the mood of the day) and voila!...

IF a little bit of oil first and no mineral ground, then 'ossify' doesn't matter ['cause 'oil' doesn't ossify]. :)

Jim

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One of the biggest chores dealing with anything having to do with authentic Cremonese varnish descriptions, is the gaining an ability to strip away the various "romantic" descriptions and hyperbole.

If one was to list all of the miraculous attributes given to this varnish, they would rival the Bibles depiction of heaven itself.

At the risk of being branded an unromantic heretic, I'll offer my casual and unprofessional observation of the Titian:

Old, with some clear-ish stuff on the wood and a few remaining areas of deep red-brown varnish on top. Didn't notice anything reflective or sparkling or glowing or dancing across the room. In fact, it seemed rather the opposite: lacking the brightness and glitter of fresh new work, and showing the effects of genuine age that are nearly impossible to copy. I tried to imagine a new Titian, covered completely with that heavy but intense red-brown, and I'm glad most of it is worn off so we can see more of the wood.

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so simple even a caveman could do it :lol:

So they DID find linseed at the wood surface? Was it definately identified as linseed? or could it have been something else?

According to the 2010 article in Angew Chem. Int. journal, they typically found 2 layers. A layer of drying oil (but no, they don't say it's linseed oil, just that it's partially oxidized) that penetrates into the first cell of spruce and maple (deeper in maple), then a second layer with seemingly the same drying oil but with resin and sometimes pigments.

The same pattern was found in 5 instruments attributed to Stradivari, that span nearly 30 years. they don't say the exact location of the wood/varnish samples they used, but state the areas were "carefully chosen". So I expect some luthier advised them so that no trivial error was introduced or bias when the sample were chosen.

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IF a little bit of oil first and no mineral ground, then 'ossify' doesn't matter ['cause 'oil' doesn't ossify]. :)

Jim

You're right, and the picture that you posted, showed in the article, seems quite clear that except for the first one or 2 layers of wood cells (filled with the drying oil), the rest of the wood looks empty. Of course one could always argue that the treatment before EM could have messed with it (and it's a common worry for EM scientists I met and in microscopy in general), but if really a solution of silicate or other had been used to soak the wood, some of it most likely would have been detected.

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So they DID find linseed at the wood surface? Was it definately identified as linseed? or could it have been something else?

As I recall, reading somewhere, there is pretty much a toss up between; was it linseed oil, or walnut oil? - but again, I usually don't bother keeping too close an eye on the "latest" resaerch,

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At the risk of being branded an unromantic heretic, I'll offer my casual and unprofessional observation of the Titian:

Old, with some clear-ish stuff on the wood and a few remaining areas of deep red-brown varnish on top. Didn't notice anything reflective or sparkling or glowing or dancing across the room. In fact, it seemed rather the opposite: lacking the brightness and glitter of fresh new work, and showing the effects of genuine age that are nearly impossible to copy. I tried to imagine a new Titian, covered completely with that heavy but intense red-brown, and I'm glad most of it is worn off so we can see more of the wood.

Now, now...Sacconi tells you to put a drop of oil to "reviva".

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Reading again Echard et al work conclusions.

So lots of italian sun and a natural yellow/golden brown wood, a little bit of linseed/drying oil first, then a colored oil/resin varnish (iron oxyde/vermillon, cochineal or madder lake depending of the mood of the day) and voila!... :)

From working on them a bit, I doubt whether that is the whole picture. The layer at the bottom seems much more durable than linseed oil, unless linseed oil changes more in 300 years than I realize. Still, it shows evidence of having been pretty durable early on, much more so than the top varnish. That's one of the reasons I asked Bruce Tai (in another thread) whether the testing methods would have been capable of finding everything which could be there.

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From working on them a bit, I doubt whether that is the whole picture. The layer at the bottom seems much more durable than linseed oil, unless linseed oil changes more in 300 years than I realize. Still, it shows evidence of having been pretty durable early on, much more so than the top varnish. That's one of the reasons I asked Bruce Tai (in another thread) whether the testing methods would have been capable of finding everything which could be there.

It would have to be something really elusive and pretty thin, almost molecular thinness. One thing possible though is that the wood itself can react with the linseed oil over time to create a barrier that would be harder than the wood or the oxidised oil, but that would not be detectable since it doesn't contain anything new (it would be confused with the remnant of the oil detected).

So rather than ossification, we would be talking about mummification.

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does anyone think that maybe the linseed oil on the surface got there after stradivari, obviously linseed oil could never fit the physical characteristics of the ground coat as david points out, its common to polish instruments with abrasive and linseed oil, did the researchers take their ground samples from exposed areas, or actually peel off some varnish and get under it? of all the undercoats that i have seen proposed only silicate and possibly casein seem to match the hardness and resistance to wear of the strad undercoat, linseed oil is certainly not known for its resistance to wear.....

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Greiner and Brandmair indicate this being a protein based upon UV color and chemical tests for protein, followed by a clear, short oil varnish. Casein once hardened is like a hard plastic, in fact they used to make buttons and other plastic articles from it. Being a water based solution, it seems reasonable that it would be easy to apply as a thin solution , would fill the top layer of the wood and harden into a very solid base for the varnish. It is also unaffected by water and most solvents after curing. Casein was well known even in ancient times, so it wouldn't be unreasonable to think the 15th century craftsmen utilized it.

If you accept their research as being valid and accurate, it fits the observations of Sacconi, only a different , mineral free substance is utilized compared to Sacconi's speculation.

I'm sure most of us are all aware of these facts, but I thought I would repost this info for the benefit of those newcomers considering mineral grounds.

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At the risk of being branded an unromantic heretic, I'll offer my casual and unprofessional observation of the Titian:

Old, with some clear-ish stuff on the wood and a few remaining areas of deep red-brown varnish on top. Didn't notice anything reflective or sparkling or glowing or dancing across the room. In fact, it seemed rather the opposite: lacking the brightness and glitter of fresh new work, and showing the effects of genuine age that are nearly impossible to copy. I tried to imagine a new Titian, covered completely with that heavy but intense red-brown, and I'm glad most of it is worn off so we can see more of the wood.

I'm glad to hear this description, I get the impression it is more realistic than all the grandiose adjectives.

"I tried to imagine a new Titian, covered completely with that heavy but intense red-brown, and I'm glad most of it is worn off so we can see more of the wood."

Does this mean the red brown varnish is not entirely transparent so you wouldn't see the wood as clearly through it? Now that's getting into varnish rather than ground but it's all related so I have to ask.

I don't suppose anyone knows what the mythical ground substance might be soluble in? Not sure if that would be a clue since the solubility of things may change over time and 300 years is a long time.

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does anyone think that maybe the linseed oil on the surface got there after stradivari, obviously linseed oil could never fit the physical characteristics of the ground coat as david points out, its common to polish instruments with abrasive and linseed oil, did the researchers take their ground samples from exposed areas, or actually peel off some varnish and get under it? of all the undercoats that i have seen proposed only silicate and possibly casein seem to match the hardness and resistance to wear of the strad undercoat, linseed oil is certainly not known for its resistance to wear.....

good point too, and with polishing maybe there might end up a deposit of abrasive particles and maybe a thin layer of french polish over that and what might that look like under an electron microscope?

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Greiner and Brandmair indicate this being a protein based upon UV color and chemical tests for protein, followed by a clear, short oil varnish. Casein once hardened is like a hard plastic, in fact they used to make buttons and other plastic articles from it. Being a water based solution, it seems reasonable that it would be easy to apply as a thin solution , would fill the top layer of the wood and harden into a very solid base for the varnish. It is also unaffected by water and most solvents after curing. Casein was well known even in ancient times, so it wouldn't be unreasonable to think the 15th century craftsmen utilized it.

If you accept their research as being valid and accurate, it fits the observations of Sacconi, only a different , mineral free substance is utilized compared to Sacconi's speculation.

I'm sure most of us are all aware of these facts, but I thought I would repost this info for the benefit of those newcomers considering mineral grounds.

I seem to remember reading somewhere that they may have used casein rather than hide glue to glue the ribs to the blocks? and maybe for the center seams also? But that was just someone speculating.

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