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what does ossify mean?


MikeC
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Trying to understand some terminology..

ok, I know the dictionary definition but in some posts on MN and google search I found that Sacconi (I don't have the book) thought that the Cremona builders used Pot. silicate, modern makers seem to think that's a bad idea.

What I'm wondering though is what physical characteristics of the wood prompt Sacconi to use the term ossified? What does ossified mean in the context of violin wood? Does that mean that the wood is harder than normal wood? or what ?

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Trying to understand some terminology..

ok, I know the dictionary definition but in some posts on MN and google search I found that Sacconi (I don't have the book) thought that the Cremona builders used Pot. silicate, modern makers seem to think that's a bad idea.

What I'm wondering though is what physical characteristics of the wood prompt Sacconi to use the term ossified? What does ossified mean in the context of violin wood? Does that mean that the wood is harder than normal wood? or what ?

Mike,

You will be familiar with the fact that wood has a directional structure owing to the grain. This means that how it behaves under the chisel or gouge depends on how you are working it in relation to the grain.

Sacconi was fascinated by the fact that in old Cremonese violins, the wood seemed to have lost its grain. It behaved in the same way regardless of whether he was working with, or against the grain. He used the word 'Ossification' to describe what had taken place in the wood to produce this effect i.e transformed into bone or ivory.

Glenn

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Just so nobody has to look it up... ossificatin has to do with formation of bone, or hardening in a more general sense. I suspect a more appropriate term would be "silicification", where wood becomes replaced with silica, as in petrified trees. At one time, that seemed to me to be a promising avenue... silica does have good acoustic properties, and if you could get silica into a low-density cell-like structure, it might be interesting. And maybe that's true, but nobody has been able to make such a material, and attempts by me and others to use silicates to modify or coat wood have all been pretty poor.

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Mike,

You will be familiar with the fact that wood has a directional structure owing to the grain. This means that how it behaves under the chisel or gouge depends on how you are working it in relation to the grain.

Sacconi was fascinated by the fact that in old Cremonese violins, the wood seemed to have lost its grain. It behaved in the same way regardless of whether he was working with, or against the grain. He used the word 'Ossification' to describe what had taken place in the wood to produce this effect i.e transformed into bone or ivory.

Glenn

There are a few posters on this board who have worked quite extensively on old Cremonese instruments. Can they confirm whether or not Sacconi was correct in this claim?

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What Sacconi probably meant by "ossify" was to harden, or cause to become more rigid, and he seems to have associated it with the incorporation of minerals, as when wood is becoming petrified. His theory was that this was accomplished by coating or impregnating the surface with a "liquid mineral" (potassium silicate or sodium silicate), which would then harden.

It doesn't seem to work very well in practice, and I would advise against using it. For one thing, it lowers the long-term resistance of the wood to bending. Not that the general concept is necessarily without merit, but it would need more work, or a different approach.

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i had very good results using potassium silicate under the varnish on my clavichords, its very important to dilute the silicate 3 or 4 parts of water to one part silicate, stronger solutions dont help the tone at all, suprisingly while the silicate was a big help with engelmann spruce soundboards, when i used heavier tennessee red spruce(which is more similar to european in density) it wasnt necessary.

ive heard people in the business say silicate is most usefull when an instrument is overly thin and needs to be strengthened, but not so useful for a normally thick instrument, given that a lot of people are reccomending very thin graduations here on maestronet, i think experimenting with a light watered down silicate solution may not be such a bad idea, it brightens the sound and seems to improve the ring when you tap on the wood, using full strength silicate will deaden the tone though and i think thats where the previous posters got their distaste for it

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What Sacconi probably meant by "ossify" was to harden, or cause to become more rigid, and he seems to have associated it with the incorporation of minerals, as when wood is becoming petrified. His theory was that this was accomplished by coating or impregnating the surface with a "liquid mineral" (potassium silicate or sodium silicate), which would then harden.

It doesn't seem to work very well in practice, and I would advise against using it. For one thing, it lowers the long-term resistance of the wood to bending. Not that the general concept is necessarily without merit, but it would need more work, or a different approach.

David,

Sacconi certainly claims that Stradivari's wood preparation imparted 'resistance' to the wood separate from the tonal effects.

He mentions specifically that Strad's instruments do not show the same degradation due to hand wear and sweat as is seen on the tops of instruments by other makers.

He also adds that chins and beards wear the wood into grooves between the annual growth rings but this is not seen on Strad violins.

If true, and given his familiarity with Italian violins there seems no reason to doubt him, this strongly suggests a special treatment of the wood to give it bone-like strength.

It then become reasonable to suppose that such treatment had some influence on performance characteristics.

Lyndon, I'm interested in your experience with soluble silicates. I tried Sacconi's waterglass treatment many years ago but I used it thick and viscous. I wish I had tried diluting it as you suggest,

Glenn

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David,

Sacconi certainly claims that Stradivari's wood preparation imparted 'resistance' to the wood separate from the tonal effects.

He mentions specifically that Strad's instruments do not show the same degradation due to hand wear and sweat as is seen on the tops of instruments by other makers.

He also adds that chins and beards wear the wood into grooves between the annual growth rings but this is not seen on Strad violins.

If true, and given his familiarity with Italian violins there seems no reason to doubt him, this strongly suggests a special treatment of the wood to give it bone-like strength.

It then become reasonable to suppose that such treatment had some influence on performance characteristics.

Right. It's just that "waterglass" doesn't seem to be a very good candidate, unless it is reacted somehow to make it more inert. It performed very poorly as a protectant when I used it on knife handles, which is one way I test varnishes and coatings. And in my tests, it made the frequency of test strips drop over time, even if they had become higher than untreated wood upon initial application. It also seemed to cause wood to undergo an exaggerated change in water content with humidity fluctuations.

I tried it in various dilutions.

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thanks glen to reproduce my success with silicate, here is what i did; i ordered potassium silicate from kremer pigments which is about the consistency of honey or a little more fluid, water this down 3 or 4 parts water to one part silicate, one coat brushed on thick, then a minute later wipe the excess off with a dry cloth and let dry, it will turn the wood a greenish tint, dont worry this will change to a nice yellow brown over a few days, the silicate seals the pores and stops the varnish from soaking in very effectively so you can go straight to oil varnish over the silicate ground, the silicate mostly boosts the highs so if youre not interested in a brighter sound, the silicate is probably not for you.

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He also adds that chins and beards wear the wood into grooves between the annual growth rings but this is not seen on Strad violins.

I've seen this on Strads. Maybe he wanted to indicate that there is not as much of it on Strads compared to other violins of the same age? But I'm not sure about this. Could also be that Strads have been treated better than f.e. a Ruggieri to begin with.

Matthias

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like i said i was using silicate on clavichord soundboards, i never had a glue join fail or the soundboard warp, youre getting the wood wet but for a very short time, as far as it rotting wood, i find this very hard to believe, silicate dries to a hard, glass like nature, how this could interact with the wood to rot it, i cannot see that, perhaps there talking about silicate prepared by the directions in sacconis book

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David,

Sacconi certainly claims that Stradivari's wood preparation imparted 'resistance' to the wood separate from the tonal effects.

He mentions specifically that Strad's instruments do not show the same degradation due to hand wear and sweat as is seen on the tops of instruments by other makers.

He also adds that chins and beards wear the wood into grooves between the annual growth rings but this is not seen on Strad violins.

If true, and given his familiarity with Italian violins there seems no reason to doubt him, this strongly suggests a special treatment of the wood to give it bone-like strength.

It then become reasonable to suppose that such treatment had some influence on performance characteristics.

Lyndon, I'm interested in your experience with soluble silicates. I tried Sacconi's waterglass treatment many years ago but I used it thick and viscous. I wish I had tried diluting it as you suggest,

Glenn

It seems to me that application of casein as has been suggested from research, could produce the same properties in the wood.

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Potassium silicate has a ph of 11.3. At least this was from an online source. Not sure of the concentration. I had heard that the alkaline nature of waterglass is bad for the wood over the long term. As pointed out above it is hydroscopic. But then again so is wood...

Did the cremonese have access to potassium silicate?

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as a liquid it may be quite alkaline, but when its dried its a very hard solid, dont know how that can be alkaline, but it doesnt redissolve in water once dry as i remember, doesnt it at least have to soften in water to be hydroscopic

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Potassium silicate has a ph of 11.3. At least this was from an online source. Not sure of the concentration. I had heard that the alkaline nature of waterglass is bad for the wood over the long term. As pointed out above it is hydroscopic. But then again so is wood...

Did the cremonese have access to potassium silicate?

I wonder how this could react with a acid resin ..over the long haul? with moisture cycling?

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Wood is pretty stable stuff, in the right environment. Ph extremes are probably a no-no.

as a liquid it may be quite alkaline, but when its dried its a very hard solid, dont know how that can be alkaline, but it doesnt redissolve in water once dry as i remember, doesnt it at least have to soften in water to be hydroscopic

In our normal environment (and particularly in the vicinity of a player), there is always moisture present. Something does not need to dissolve in water to be hygroscopic.

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It's amazing how violin making can lead to all kinds of subjects, even the most unlikely

Yes, and they can be informative.

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).

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Yes, and they can be informative.

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).

Oh yes, I have been working with proteins for quite a while. My post was refering to your previous link about the funeral alternative to body cremation but you posted the second link while I was typing :) ...

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Wow, lot's of responses. The first response mentioned that the grain structure is lost that the wood becomes homogeneous? That would mean that the wood would not split along grain lines but haven't I seen pictures of patches under the belly of Strads due to cracks? or not? So it is the general concensus that silicate application is not a good idea unless it is diluted as Lyndon says.

Has anyone ever thought of or tried soaking tone wood in water that has a high mineral content to mineralize it?

I also read somewhere recently the idea of boiling tone wood in salt water, has anyone ever heard of that?

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any prolonged exposure to water is not good for tone in my experience, my experience is lumber that has got wet in the yard is ruined as far as soundboard use goes, on the other hand some claim strads wood was soaked in water as logs before being made into violins, theres just one problem with this theory, logs that are soaked in water dont float, they are waterlogged and sink to the bottom of the river/bay, in floating a log down the river i dont think the water penetrAtes that far

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