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scordatura

Casein as a Sealer Questions

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2 hours ago, jezzupe said:

Well for those who may be using egg, I, being a Chickeneer :D or Poultryman {one who keeps chickens} am starting to come to the conclusion that not all eggs are the same and that diet modifications in your fowl will modify the end product and characteristics of the egg,it's shell, components and the byproducts of those components.

For example there are those who will feed black oil sunflower seeds regularly,vs just for treats, there is a distinct difference in the eggs quality and characteristics

Just to throw one more potential tangent out there, maybe there were special Stradivarius chickens fed special diets to produce a certain type of glair or base for tempera  

edit; not to mention the difference in the eggs based on breed 

 

Ah the nuances of the "you are what you eat" premise. Perhaps I need to rethink my own consumption. That is what my wife tells me...:unsure:

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2 hours ago, scordatura said:

Ah the nuances of the "you are what you eat" premise. Perhaps I need to rethink my own consumption. That is what my wife tells me...:unsure:

Well, I just like the thought of some special chickens being "the secret" :lol: ba'kop'

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10 hours ago, Don Noon said:

I'm sure it does... by making the whole instrument look like a ghost.

As I am unburdened by the need to maintain historical accuracy or appearance, that lets me decide what I want my instruments to look like, and test whatever materials and processes get the desired result.

As the "glue ghost" issue implies, I have found that water-born protein, be it glue or casein or whatever, tends to reduce contrast and visibility into the wood.  Maybe that's OK for spruce, but I think it kills off the fire of the maple.  And maybe it's even historically accurate... I don't know.

But in my limited observations of a few old Italian instruments, many of them DO look to me rather flat and dull compared to more modern instruments.  Below are some comparisons of a modern (mine), with a Guarneri and a Strad taken in the same place, same lighting, same camera.  I was especially struck by  the complete lack of any sparkle in the spruce... no rays, no nothing, like it was a painting.  I have no idea why that would be, but since the same effect was present in the areas of original varnish AND the areas where it was completely worn off, I'm kinda thinking that the cell walls have become extremely opaque. (BTW, my instrument has torrefied wood, and the spruce is a very dark example from my earlier batches).

In any case, the point is to test out all these ideas and make a serious evaluation of what you get, and decide if that's what you want.

839603152_Topcomparison.jpg.0ed0c4fad7682f03eb452d90bafc7911.jpg1093400329_Backcomparison.jpg.bdd8a1ca8036cc12cc1b56ecb80ad1db.jpg

Don do you just go with a lean colorless linseed/resin for your first contact? You make your own varnish from what I remember.

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12 hours ago, scordatura said:

Don do you just go with a lean colorless linseed/resin for your first contact? You make your own varnish from what I remember.

I'm not sure I've done the exact same thing twice, but mostly I have been trying to use a resin/solvent on the wood.  Things I have tried:  shellac, terpene, copal, pontianak, damar, often with slight added colorant.  I'll probably do something different next time.

I have used casein/ammonia at times as well, mostly on the spruce.

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18 hours ago, jezzupe said:

Well for those who may be using egg, I, being a Chickeneer :D or Poultryman {one who keeps chickens} am starting to come to the conclusion that not all eggs are the same and that diet modifications in your fowl will modify the end product and characteristics of the egg,it's shell, components and the byproducts of those components.

For example there are those who will feed black oil sunflower seeds regularly,vs just for treats, there is a distinct difference in the eggs quality and characteristics

Just to throw one more potential tangent out there, maybe there were special Stradivarius chickens fed special diets to produce a certain type of glair or base for tempera  

edit; not to mention the difference in the eggs based on breed 

 

I was told by a poultry scientist that free-range chickens lay orange yolk eggs because they nibble on plants having chlorophyll.

Another factoid from my vast warehouse of worthless knowledge.  :D

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12 minutes ago, Michael_Molnar said:

I was told by a poultry scientist that free-range chickens lay orange yolk eggs because they nibble on plants having chlorophyll.

Another factoid from my vast warehouse of worthless knowledge.  :D

I don’t see how. Maybe carotenoids?

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22 hours ago, jezzupe said:

fwiw, those who use "glue" for a sealer, and are concerned about cracking, the addition of some sugar will eliminate the cracking issue by dramatically reducing the glue strength 

Right. My reading points to polysaccharides such as gum Arabic. Lots of linked sugar molecules. 

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On ‎11‎/‎9‎/‎2019 at 2:01 PM, Michael_Molnar said:

Checking again B&G, I disagree with your cavalier dismissal of protein identification as an unintentional or accidental contamination by morning breakfast or sloppy workmanship. The use of protein follows a standard historical practice of artistic coloring during the Renaissance: Tempera.

An artist tempera is not a sealed ground. On Strad's iinstruments, I claim that a tempera infuses the underlying wood fibers unobstructed by a sealant. This produces beautiful optical effects that enhance the wood figure. Ordinarily, artists put a ground gesso on wood panels to hide the figure. Strad enhanced it.

Modern makers use proteins as a sealant to avoid blotching from capillary action wicking up the colorant. (My tempera does not blotch spruce.) I believe that Greiner made this mistake of sealing the wood due to his formal training as a luthier. Collagen and casein are such sealants. 

I hope this clears up the noise for @sospiri who needs to read B&G big time.

 

So that's your hypothesis, that Strad used tempera. Why didn't Echard find it?

I'm not dismissing the idea, but why should we accept it. Yes we need to avoid blotching from capillary action and a method of enhancing the wood figure. Why can't linseed oil do that? Have you tried it? And if you did, would you not expect collagen from the manual rubbing to be present?

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8 minutes ago, sospiri said:

So that's your hypothesis, that Strad used tempera. Why didn't Echard find it?

I'm not dismissing the idea, but why should we accept it. Yes we need to avoid blotching from capillary action and a method of enhancing the wood figure. Why can't linseed oil do that? Have you tried it? And if you did, would you not expect collagen from the manual rubbing to be present?

The problems with just going hog wild with linseed oil on a white violin are well understood. Not saying it can't or shouldn't be a small components of a ground, but that is probably it 

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1 minute ago, JacksonMaberry said:

The problems with just going hog wild with linseed oil on a white violin are well understood. Not saying it can't or shouldn't be a small components of a ground, but that is probably it 

I have explained how to get round the problems enough times. It gets boring after a while. A small amount seals the wood.

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20 minutes ago, sospiri said:

I have explained how to get round the problems enough times. It gets boring after a while. A small amount seals the wood.

Forgive me if I'm misremembering, but are you the person who described rubbing powdered rosin and linseed in with your fingertips? I agree that a small amount of linseed (a few drops mixed with some other ingredients) can make for a good ground, but that's as far as I'd go.

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I encourage you to read the literature. Start with V. Bucur, “Handbook of Materials for String Musical Instruments” (2016). Therein you will see how many researchers have detected proteins in Strads and other Cremonese instruments. Read the recent work by the Italian researchers at the Arvedi Lab for more work on proteins (2017 and more recent).

Echard’s (2010) failure to detect protein in the Sarasate (Strad 1724) may be a red herring for two reason. Given the variability in Cremonese work, it is possible that this (one?) instrument has no protein, but maybe instead a polysaccharide which he did not look for. The other reason could lie in a problem with his experiment. In any case, Echard did not refute the use of proteins.  Does anyone know if Echard still stands behind this null detection?

The amounts of proteinaceous layers does not look like accidental.

My hypothesis of a tempera is based on well documented historic artist practices.

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1 hour ago, Michael_Molnar said:

I encourage you to read the literature. Start with V. Bucur, “Handbook of Materials for String Musical Instruments” (2016). Therein you will see how many researchers have detected proteins in Strads and other Cremonese instruments. Read the recent work by the Italian researchers at the Arvedi Lab for more work on proteins (2017 and more recent).

Thanks for the heads up on these publications Mike. I will check them out.

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7 hours ago, sospiri said:

I'm not dismissing the idea, but why should we accept it. Yes we need to avoid blotching from capillary action and a method of enhancing the wood figure. Why can't linseed oil do that? Have you tried it? And if you did, would you not expect collagen from the manual rubbing to be present?

As to your second point about linseed oil in place of proteins, I am researching  historic methods, not the best methods. That is an important point. Your LO layer could produce superior results and so could rosin infusion.  But I am not focused on better techniques.

If you read the research papers cited in Bucur, you realize that this is not contamination. 

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1 hour ago, Michael_Molnar said:

I encourage you to read the literature. Start with V. Bucur, “Handbook of Materials for String Musical Instruments” (2016). Therein you will see how many researchers have detected proteins in Strads and other Cremonese instruments. Read the recent work by the Italian researchers at the Arvedi Lab for more work on proteins (2017 and more recent).

Echard’s (2010) failure to detect protein in the Sarasate (Strad 1724) may be a red herring for two reason. Given the variability in Cremonese work, it is possible that this (one?) instrument has no protein, but maybe instead a polysaccharide which he did not look for. The other reason could lie in a problem with his experiment. In any case, Echard did not refute the use of proteins.  Does anyone know if Echard still stands behind this null detection?

The amounts of proteinaceous layers does not look like accidental.

My hypothesis of a tempera is based on well documented historic artist practices.

Mike,

Echard has considered protein presence in more than one Strad (and a range of other instruments).  As a starting point, the conclusion in this paper is possibly worth noting: https://www.researchgate.net/publication/47511057_Identification_of_the_finishing_technique_of_an_early_eighteenth_century_musical_instrument_using_FTIR_spectromicroscopy   His Ph.D thesis should also be mentioned.  Included are papers, some of which provide more detail on protein detection and presence. 

Future results from the Arvedi Lab may prove interesting.  If Stradivari's varnish system is your focus, basing anything on the Sgarabotto sample results may be slightly premature....

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1 hour ago, John Harte said:

Future results from the Arvedi Lab may prove interesting.  If Stradivari's varnish system is your focus, basing anything on the Sgarabotto sample results may be slightly premature....

I was not referring to the Sgarabotto sample.  Thanks for the heads up, nevertheless..

 

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20 hours ago, JacksonMaberry said:

Forgive me if I'm misremembering, but are you the person who described rubbing powdered rosin and linseed in with your fingertips? I agree that a small amount of linseed (a few drops mixed with some other ingredients) can make for a good ground, but that's as far as I'd go.

You aren't misremembering. I still do that. It works very well. I use three combinations, powdered rosin and oil, powdered rosin and turpentine, and all three together. But those are all for layers above the oil ground.

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2 minutes ago, sospiri said:

You aren't misremembering. I still do that. It works very well. I use three combinations, powdered rosin and oil, powdered rosin and turpentine, and all three together. But those are all for layers above the oil ground.

Can you post a picture please? Would be nice to see the result of what you describe.

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14 hours ago, Michael_Molnar said:

I encourage you to read the literature. Start with V. Bucur, “Handbook of Materials for String Musical Instruments” (2016). Therein you will see how many researchers have detected proteins in Strads and other Cremonese instruments. Read the recent work by the Italian researchers at the Arvedi Lab for more work on proteins (2017 and more recent).

Echard’s (2010) failure to detect protein in the Sarasate (Strad 1724) may be a red herring for two reason. Given the variability in Cremonese work, it is possible that this (one?) instrument has no protein, but maybe instead a polysaccharide which he did not look for. The other reason could lie in a problem with his experiment. In any case, Echard did not refute the use of proteins.  Does anyone know if Echard still stands behind this null detection?

The amounts of proteinaceous layers does not look like accidental.

My hypothesis of a tempera is based on well documented historic artist practices.

Echard and his team examined five Stradivari instruments. What they found was a linseed oil ground and a pigmented oil/resin layer. That's it.

There have been all sorts of claims from research about his varnishing methods and Echard et al found nothing to substantiate the supposed mineral or protein layers.

Your tempera hypothesis is interesting. I will look into it.

13 hours ago, Michael_Molnar said:

As to your second point about linseed oil in place of proteins, I am researching  historic methods, not the best methods. That is an important point. Your LO layer could produce superior results and so could rosin infusion.  But I am not focused on better techniques.

If you read the research papers cited in Bucur, you realize that this is not contamination. 

I want something that looks good and doesn't turn the instrument into a screech box. I think that what players with a good ear for tone are seeking is not an instrument that is either bright or dark, but rich in tone. Both bright and dark. I believe a good mix of linseed oil and resin can help achieve that aim.

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19 minutes ago, Wood Butcher said:

Can you post a picture please? Would be nice to see the result of what you describe.

I need some help in that direction. I know how good some of the newer phone cameras are, but I don't have one.

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On 11/8/2019 at 12:11 PM, Bill Yacey said:

Are you suggesting the casein made from cheese curds is unsuitable for our purposes,  or is it suitable? I wasn't sure what your example indicates.

Bill,

When I first became interested in casein I was intrigued with the famous "cheese glue" of Theophilus Presbyter. I tried making this many times with different kinds of cheese— complete failure every time. I was, however, using aged lime putty and not quicklime, which by my way of thinking should have been an improvement. But the essential point is that I couldn't get the cheese to work. My greatest disappointment was with one of the cheese varieties that may have been eaten by Stradivari: Taleggio.

Finally, I decided to investigate the reason why the recipe was failing. Happily, there is a vast amount of material available on dairying and casein (e.g., from trade associations and institutions), and I soon discovered the reason for failure: the majority of modern cheese and similar foodstuffs are made from rennet curd/casein (enzymatic, i.e., the enzyme rennin/chymosin) as opposed to acid curd/casein. The chemistry is complex to say the least, but they do differ from each other, and thus each is suitable for particular purposes in industry.

As for cheese specifically, I was advised by a dairy researcher that the enzyme continues to be active in the cheese, and that this is not desirable in an adhesive.

Therefore, I concluded that trying to make the old cheese glue with cheese and similar products made from rennet curd will not work. I could easily break apart the glue joint. The dried glue resembled plaster, not the cement-like appearance of the real substance.

This is also an excellent example of why the old recipes need to be scrutinized, and to evaluate failure in the light of using the wrong ingredients, as well as any alterations we make with a recipe.

As for the use of rennet curd in a sealer, I understand some here do use it successfully, where aggressive adhesiveness is not desired or required.

Dave

 

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On 11/8/2019 at 3:00 PM, David Burgess said:

I still consider the use of Casein as a sizing or "filler" to be a bit sketchy. In my own experience, as well as that of some respected colleagues, it contracts so much upon drying, that it can form tension cracks. I have not used it on an actual fiddle, but one or more of my colleagues has, and there were problems, maybe not right away, but somewhere down the road.

I'll add that while some have claimed it to be water insoluble once cured, I have not found that to be true in any formulation I have tried so far.

David,

You make some valid points.

Because a thin casein solution is still an adhesive, there is naturally the risk of cracking when drying, particularly if anything less than a very, very thin layer is applied.

Cracking could also be due to the wrong type of casein and/or lime as I've mentioned. But it may occur even when the best materials are used, or sometimes the particular reason can't be identified.

For a sealer, I test the formulation using a small paper plate to observe the film quality and mechanical characteristics, primarily flexibility.

Regarding casein's water resistance, I have made seemingly waterproof casein glue with a variety of formulas, soaking the samples until the wood is saturated (see photo below). But I usually end up breaking them apart to test their wet strength, which fails after some time (samples not exposed to water retain their strength); a truly waterproof glue wouldn't yield after applying moderate force. 

Therefore, based on my testing I conclude that the historical type of casein glue should be considered water-resistant, but it is not waterproof like modern glues and epoxies made for that purpose.

Dave

 

#1 Saturated wood (casein glue water test).JPG

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On 11/9/2019 at 6:39 AM, MikeC said:

Hi Dave,  what optical characteristics are you referring to? 

Mike,

I have in mind Dr. Tai's excellent JVSA paper (2007) on Stradivari's varnish, in particular part one (pages 130-134) where he discusses minerals, particle size, their relation to transparency, and being invisible to the eye. I also mean the luminous quality of the lime crystal, and in particular its pearlescent appearance. But photos are better than talk.

First, this is a really neat photo of some very fine lime. I don't remember the specifics, but I put some of Kremer's aged lime putty in water. This is the thin layer that formed on top of the water:

106700668_2Limewaterdetail.JPG.04e181b102ab8963b601a69cdd706b0d.JPG

Second,  a caseinate sealer made with aged lime putty can be applied very thinly, to the point where it almost appears to be invisible, except in reflected light. This sample was burnished afterwards to show detail; it makes the film thickness look thicker than it actually is. Note that it doesn't fill the pores.

1438734336_3CaseinateonMaple(1).JPG.787df91777e756068b3db710d5dcf5fc.JPG

Finally, here is my caseinate sealer under the varnish on a finished instrument. I have observed that a very thin sealer with the right optical properties will allow the grain on maple to appear to rise up and roll when viewed from just the right angle, as here on the left side:

1831707743_43Dwave.JPG.4770a6c0432dfc152afd2c342e39c21b.JPG

 

Dave

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