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Old Italian Sealer


Nicolaus
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Well, who can imagine what 350 years will do to the way a burnished surface appears? It's possible that even though the interior wasn't finely finished, it may still have been given the once over with a burnishing stone to smooth things out a little for a neater appearance.

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I imagine a burnished, untreated surface would inhibit moisture transfer more than a surface left rough from application of a tool. But after several centuries' worth of moisture exchange, would one even be able to determine if a surface had been burnished?

Also, great minds want to know . . . how many of you folks have actually licked the inside of a 300 year old violin?

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.....And some old, much repaired and well working fiddles probably have a fair bit of glue size on their insides.

Hi Melvin.

Do you mean something like a 1:10 water diluted hide glue?

Also, great minds want to know . . . how many of you folks have actually licked the inside of a 300 year old violin?

Sounds like a sort of deviation, nobody will ever admit it :) .

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I remember Darnton claiming that there is a distinctive taste to the interior surface. My tongue can't fit :) , so I wonder whether he ever came up with a candidate.

Anyone buy into casein?

Mike

Mike,

Well, yes, I did buy casein... some 12 pounds or so. As you well know. But I have no knowledge of its use in violins other than what Charles Hargrave has written about.

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As a theologian by trade I would hope at least some of us do...

We have spoken privately. You know that I am not against philosophical discussion, with or without theism. I welcome it. I am recently concerned with what I learned about Islam from my shrink. He is no longer in my town, but some things were rather frightening. I would not want to live in society where apostacy was considered a crime. I like to think, I don't like to accept dogma. I assume you feel the same way.

That goes for violin dogma also.

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QUOTE (jezzupe @ May 20 2010, 12:03 AM)

I for one am personally offended by discussions about faith and religion in general and would appreciate people not discussing it on a violin forum...

---------------

Maestronet is no longer a violin discussion forum, but it has become a very poor excuse for one.

However, I do wonder what it is about discussing "faith and religion" that could possibly be (personally) offensive to you = or anyone = for that matter.

The holy scriptures state that Jesus died once, for ALL. What's so "personally offensive" about that?

lulu out.....

These things are not all that common. Much is drivel anyway. How much can one say about violins? One can say volumes about what he does not know. This entire forum probably would fit on a single hard drive. Since it started.

Your last sentence turns your first one on its head. You stand accused. (And I don't believe everything I read. But you can say that if you want.) The statement is not offensive, it just makes no sense to me.

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Mike,

Well, yes, I did buy casein... some 12 pounds or so. As you well know. But I have no knowledge of its use in violins other than what Charles Hargrave has written about.

Yes, John, I know something about that purchase. (grins) By "buy into" I was suggesting that someone may be using casein as an interior coating, and would like to share that experience.

This was my attempt to get this thread back on track, namely discussing violin issues.

Stay tuned.

Mike

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When we do western blot we transfer some proteins of interest on a nitrocellulose membrane. But before we use the membrane further we have to "block" it with BSA (serum albumin bovine) or casein or very often using a simple solution of fat free milk (it's cheap and you can buy the powder milk at the local supermarket). So I guess blocking the membrane and sealing the wood are similar in a way. In this case casein, gelatine, ovalbumin, BSA, milk, all could work fine for violin?

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violins, acoustics, religion, all pretty much the same. We all believe what we want to believe. All based mostly on blind faith :)

John, I know you started doing acoustical tests of varnishes-what did you find re casein?

Oded

Oded and Mike,

Ok, I will resurrect my primitive acoustical testing equipment and run some tests. I remember reporting that casein actually decreased the weight of wood. See anti-gravity ground. And Oded supported that conclusion (as I recall).

As for the necessity of sealers on the inside, I am reminded of my studio piano. It has a thick cloth covering on the back, installed by its previous owner to hide the wood (????? wood is ugly?????). I imagine this cloth dampens the sound. I imagine the clean bare wood on the inside of a violin has tiny fibers standing up that act like this cloth to dampen sound. A sealer would hold these tiny fibers in place and reduce damping. My theory.

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I suppose that if the sealing process of the outside of the plate is to prevent varnish from entering too deeply in the wood this could be tested (and I believe several of the members of this forum already did it) on scraps of spruce with the different solutions proposed on the thread.

I certainly can't define "fine" in term of violin accoustic, but I can say that whther I use BSA, milk, casein or few others, I (and many thousands of others around the world) was able to saturate the nitrocellulose or nylon or PVDF membrane with very similar efficiency :)

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I have never seen a coating decrease the weight of my samples, unless you measure the weight after warming in a dry oven (in which case, you're seeing water loss).

Casein was one of the better performers in the coatings category... it didn't change the wood properties much. Generally, I have found the coatings are not as good as the wood iteslf along the grain, so less effect is better. Across the grain there is more effect, but I'm presently of the opinion that crossgrain properties are much less important.

One problem with the testing is that the effects are (in the better cases) small, and not terribly repeatable. Then there's moisture content to jumble the results, too.

So my current opinion is that a good interior sealer is about the same as none, and a bad one will be worse. I haven't tested everything yet, so there might be something good somewhere. For the exterior, you definitely want some sealer to prevent oil from getting to the wood.

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I have never seen a coating decrease the weight of my samples, unless you measure the weight after warming in a dry oven (in which case, you're seeing water loss).

Casein was one of the better performers in the coatings category... it didn't change the wood properties much. Generally, I have found the coatings are not as good as the wood iteslf along the grain, so less effect is better. Across the grain there is more effect, but I'm presently of the opinion that crossgrain properties are much less important.

One problem with the testing is that the effects are (in the better cases) small, and not terribly repeatable. Then there's moisture content to jumble the results, too.

So my current opinion is that a good interior sealer is about the same as none, and a bad one will be worse. I haven't tested everything yet, so there might be something good somewhere. For the exterior, you definitely want some sealer to prevent oil from getting to the wood.

Don,

I plan to try to record "rustle" as the wood is scratched. I think this is related to damping properties at higher frequencies. Have you recorded rustle?

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Don,

I plan to try to record "rustle" as the wood is scratched. I think this is related to damping properties at higher frequencies. Have you recorded rustle?

Yes, I have done that with wedges of wood. My coated samples are way too small (I think) to get a good rustle test... haven't tried it on them. I just use the free bending mode amplitude decay to calculate damping.

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violins, acoustics, religion, all pretty much the same. We all believe what we want to believe. All based mostly on blind faith :)

John, I know you started doing acoustical tests of varnishes-what did you find re casein?

Oded

This John?? Just that Chinese violins coated inside and out with about 10% ammonia casein are more centered and bighter (without being harsh.) I like the effect, others may not of course.

Paint it on and wipe off excess after a short time. What remains looks like wood. The ammonia darkens somewhat, but just barely. It is not an especially good sealer, but has some sealing properties.

In other words, it is not a ground. I think it would be a mistake to build it up to make a shiny surface. Likely adherence of varnishes would be very bad.

By the way, the "rustle test" is louder with the casein.

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Yes, I have done that with wedges of wood. My coated samples are way too small (I think) to get a good rustle test... haven't tried it on them. I just use the free bending mode amplitude decay to calculate damping.

I am also thinking of the aye-aye and tapping. I am quite sure tapping with the fingernail on bare wood and coated wood will give different results. I hope my cheap little microphone can tell the difference.

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For the exterior, you definitely want some sealer to prevent oil from getting to the wood.

Which contradicts Echard, et al's, latest research. So are you saying he is wrong, or that Stradivari was wrong? I've applied oil to bare wood on actual fiddles, but since you "know" what happens I won't bother to report the results.

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I know what happens in my tests, which is similar to Schleske's varnish test results: oil on wood leads to high damping, which deadens the sound. Naturally, my tests only span a year or two, and Schleske's was over 9 years. 300 years is likely to be different, but I want to achieve a certain result within my remaining lifetime. Strad may have put oil directly on the wood... but we don't really know what they sounded like then, or how the sound changed over time.

If you have some results that are different, please share.

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I know what happens in my tests, which is similar to Schleske's varnish test results: oil on wood leads to high damping, which deadens the sound. Naturally, my tests only span a year or two, and Schleske's was over 9 years. 300 years is likely to be different, but I want to achieve a certain result within my remaining lifetime. Strad may have put oil directly on the wood... but we don't really know what they sounded like then, or how the sound changed over time.

If you have some results that are different, please share.

Here is one on tung oil. Not much added damping here..

post-25136-1274574410.jpg

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Here is one on tung oil. Not much added damping here..

Which brand?, not all tung oils are alike, many, like Watco have dryer's which will make them harden and not be so "oil" like. Raw tung oil would not harden, and would take much more time to dry out. Tung oil in general is a thinner oil.

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