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Casein as a Sealer Questions


scordatura

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9 minutes ago, MANFIO said:

Bene, io, si può dire, sono Italo Brasiliano....  this make things even more complicated!

Most of us US residents come from various combinations of cultures and ancestry, too. 

My wife probably is partly Cherokee, and I am probably largely of Scottish ancestry, based on oral history passed down through our families. Neither of us have done genetic DNA testing yet, because we don't think that determination of genetic background really matters.

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1 hour ago, jezzupe said:

I'm sure you'd agree that once you get past that hard crunchy part it's all smooth sailing from there ;), hey your wife should run for president!

I would question whether she is ferociously  loud-spoken and inherently combative enough to have any sort of a chance. She has attained high levels in her trade, but probably wouldn't want to take on all the bashing and BS involved in a presidential run.

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On ‎11‎/‎5‎/‎2019 at 12:16 PM, joerobson said:

 Ms. Brandmair holds to the findings without speculation.   Taking the findings and testing methods to those familiar with the tests was revealing.   The test is extremely sensitive.  The protein on the surface could be egg from breakfast, glue smears, or most likely the evidence that the wood was handled by humans. 

Beyond that,  the other characteristics of the Ground do not agree with a casein sealed surface.

Protein grounds can be quite effective.   It is just not as found on the classic Cremonese instruments that have been studied.

on we go,

Joe

Thank you Joe. That makes so much sense amongst background noise of the could be and the maybes.

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Back to the topic...

This is a quote from the B&G book from page 18. This seems to put aside the accidental and possibly insignificant contamination. This is from Greiner's section so the nay sayers have some ammunition here.

"We consistently found significant quantities of protein in the uppermost structure of the wood. ... Had we found only isolated areas of protein on the instruments, we would have had to consider the possibility of glue residue or an accidental transfer of protein, through foodstuffs, for example. However, due to the consistency with which we were able to establish the presence of these proteins in all samples across the entire production span of Stradivari's instruments and at different places on the instruments, the possibility of a coincidence can be ruled out."

This does contradict the findings from Echard where no protein was found. 

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25 minutes ago, scordatura said:

Back to the topic...

This does contradict the findings from Echard where no protein was found. 

Echard also only identified linseed oil in the ground so his findings are incomplete. I don't think the protein is casein.   Just as an aside,  none if them found a thick mineral ground either.  

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Electron microscope images (Source John Harte casein top, hide glue bottom) showed that casein is more porous than hide glue (at least in that casein formulation). IF one was going to use a sealer, is this desirable if you seal first and then stain? By stain I mean using an oxidizer like sodium or potassium nitrite or a pigment tempera as Mike Molnar, etc. I think that Mike does not seal...Does the porosity of the casein allow stain penetration but not  have an uneven application due to more or less absorption (end grain) when NOT sealing? It seems to me that the concentration and/or thickness of the sealer is also a significant factor.

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On 11/5/2019 at 5:16 PM, joerobson said:

Yes. Ms. Brandmair holds to the findings without speculation.   Taking the findings and testing methods to those familiar with the tests was revealing.   The test is extremely sensitive.  The protein on the surface could be egg from breakfast, glue smears, or most likely the evidence that the wood was handled by humans. 

Beyond that,  the other characteristics of the Ground do not agree with a casein sealed surface.

Protein grounds can be quite effective.   It is just not as found on the classic Cremonese instruments that have been studied.

on we go,

Joe

If all of the histological findings are due to contamination, how it is possible that they found casein on 3-4 cell layers under full varnish? 

 

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8 minutes ago, MikeC said:

I thought B&G identified it as having a resin content?  no?   Also they found protein and stain which Echard didn't find.  

Yes as I understand it they did not detect only linseed oil. They mention a 4 to 1 resin to linseed oil combination. It might have just been Greiner. I will have to check my book.

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4 hours ago, MikeC said:

I thought B&G identified it as having a resin content?  no?   Also they found protein and stain which Echard didn't find.  

Who do you want to believe? I don't know, myself. Both seem to be really good research.

I do tend to be a bit suspicious of conclusions drawn from viewing under UV light, since back when I was trying to hide repairs from even the experts,  it was possible to match any succession of color layers, using a variety of dyes and pigments.

In other words, I don't think that a color alone under UV light tells you much. I would like to see it fleshed out with chemical analysis.

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7 hours ago, scordatura said:

Electron microscope images (Source John Harte casein top, hide glue bottom) showed that casein is more porous than hide glue (at least in that casein formulation). IF one was going to use a sealer, is this desirable if you seal first and then stain? By stain I mean using an oxidizer like sodium or potassium nitrite or a pigment tempera as Mike Molnar, etc. I think that Mike does not seal...Does the porosity of the casein allow stain penetration but not  have an uneven application due to more or less absorption (end grain) when NOT sealing? It seems to me that the concentration and/or thickness of the sealer is also a significant factor.

Scordatura, these are good questions but difficult to answer.  You touch on factors that will have a significant influence on how things work or don't.  The best that you can do is to try as many options as you can and find what works for you.  A casein size can absorb stain.  However the concentration and/or thickness, what you use to create the casein size; i.e., quicklime, ammonia etc., the extent to which the casein size has dried/hardened, the type of stain involved, the nature of the wood etc., etc., will all matter.

Nitrites are normally applied directly to wood.  A casein size might be applied after that if you want to avoid varnish penetrating into the wood structure.  Other stains might be best applied after some form of glue size is applied.  It depends on what you are using and the look that you are after.

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Let me add this which I discussed with @joerobson this morning. I am writing up my notes and here are excerpts that are very appropriate to share at this time.

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

My procedure focuses on four layers in the Stradivari varnishing system defined in B&G. Interestingly, this 4-layer model was used also by Karl Roy with some minor differences.[1]

·         Layer 1: Priming the wood with proteins.

·         Layer 2: Coloring the wood by staining and filling the wood pores.

·         Layer 3: Clear varnish coat.

·         Layer 4: Colored varnish coat(s).

The similarity between B&G and Roy suggests to me that their interpretation, specifically Greiner’s and not Brandmair’s, is skewed and biased by modern luthier training. It is important to realize that the B&G book has two sections. The first is by luthier Greiner with his interpretations while the second is by scientist Brandmair with her methodology, data, analysis, and conclusions. So, Brandmair did not always buy into Greiner’s interpretation.  I arrived at my system purely out of necessity, namely to get the observed varnish appearance and stay within the scientific findings of Brandmair and others:

·         Layer 1: Darken the wood surface by staining with aqueous reactants.

·         Layer 2: Permeate the wood with protein-infused colorant that fills wood pores.

·         Layer 3: Clear varnish coat.

·         Layer 4: Colored varnish coat(s).

So, my system digresses from Greiner’s section in B&G in the order and details of Layers 1 and 2. However, this still agrees with Brandmair’s data and interpretations that she offered. In addition, it fits in with observations by other researchers.

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

Greiner in B&G defines Layer 1 as the protein impregnation layer and here we differ. My very extensive tests found that protein applied to bare wood seals and hinders any subsequent staining or coloring of wood structure.[2] Most makers feel that proteins such as hide glue (collagen), egg yolks (or whites), or casein[3] are needed to prevent blotching. The strong capillary wicking of aqueous colorant produces staining on end-grain protruding on the recurve sections of the violin plates. This is true especially for spruce where the end-grain fibers behave as straws drawing excess colored stain and producing ugly blotches.[4] Greiner’s training as a luthier may have biased his interpretation of Brandmair’s data. However, I found that protein sizes are not needed to prevent blotching. In fact, proteins applied too early in the process prevent color entering the wood.

Brandmair detected casein, egg albumin and/or collagen (gelatin or hide glue) under Stradivari’s varnish. She and Greiner believed that the purpose of the protein was two-fold. First, it can optically wet the wood making fine details discernible and increases the contrast by encapsulating wood fuzz that scatters white light. Wood workers say that sizing makes the wood figure “pop”. Second, the protein controls the saturation of the pore-filling stain that she described as a polar aqueous medium.[5]

Brandmair differs from Greiner in assigning the process order for protein infusion. She explains that the proteins that she detected could have been applied in several different orders and methods.[6] That is, the protein could have been dissolved in water then: (1) rubbed into the wood and followed by coating with the stain, (2) laid over the dried stain on the wood, (3) applied to wet stain on the wood, or (4) mixed with the stain before working this into the wood. I will explain later that I rejected method 1 and now use a hybrid procedure of options 2 and 4.


[1] Karl Roy, “The Violin: Its Making and History”, p. 296.

[2] I owe a debt of gratitude to John Harte for pointing out this evidence with his extensive photographic library of classical instruments.

[3] skim milk, quark a.k.a. farmers cheese

[4] B&G, p. 17.

[5] B&G, p. 22 referred to this aqueous medium as polar which means that it could be water or alcohol, but water is extremely polar.

[6] B&G, p. 61.

 

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47 minutes ago, jezzupe said:

I'm just going to throw this out there, I think using casein as a sealer is pretty cheesy.

:lol:

37 minutes ago, Michael_Molnar said:

Let me add this which I discussed with @joerobson this morning. I am writing up my notes and here are excerpts that are very appropriate to share at this time.

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

My procedure focuses on four layers in the Stradivari varnishing system defined in B&G. Interestingly, this 4-layer model was used also by Karl Roy with some minor differences.[1]

·         Layer 1: Priming the wood with proteins.

·         Layer 2: Coloring the wood by staining and filling the wood pores.

·         Layer 3: Clear varnish coat.

·         Layer 4: Colored varnish coat(s).
 

I still am not very impressed. I do things much differently, and it seems to work out OK. ;)

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1 hour ago, Michael_Molnar said:

Let me add this which I discussed with @joerobson this morning. I am writing up my notes and here are excerpts that are very appropriate to share at this time.

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

My procedure focuses on four layers in the Stradivari varnishing system defined in B&G. Interestingly, this 4-layer model was used also by Karl Roy with some minor differences.[1]

·         Layer 1: Priming the wood with proteins.

·         Layer 2: Coloring the wood by staining and filling the wood pores.

·         Layer 3: Clear varnish coat.

·         Layer 4: Colored varnish coat(s).

The similarity between B&G and Roy suggests to me that their interpretation, specifically Greiner’s and not Brandmair’s, is skewed and biased by modern luthier training. It is important to realize that the B&G book has two sections. The first is by luthier Greiner with his interpretations while the second is by scientist Brandmair with her methodology, data, analysis, and conclusions. So, Brandmair did not always buy into Greiner’s interpretation.  I arrived at my system purely out of necessity, namely to get the observed varnish appearance and stay within the scientific findings of Brandmair and others:

·         Layer 1: Darken the wood surface by staining with aqueous reactants.

·         Layer 2: Permeate the wood with protein-infused colorant that fills wood pores.

·         Layer 3: Clear varnish coat.

·         Layer 4: Colored varnish coat(s).

So, my system digresses from Greiner’s section in B&G in the order and details of Layers 1 and 2. However, this still agrees with Brandmair’s data and interpretations that she offered. In addition, it fits in with observations by other researchers.

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

Greiner in B&G defines Layer 1 as the protein impregnation layer and here we differ. My very extensive tests found that protein applied to bare wood seals and hinders any subsequent staining or coloring of wood structure.[2] Most makers feel that proteins such as hide glue (collagen), egg yolks (or whites), or casein[3] are needed to prevent blotching. The strong capillary wicking of aqueous colorant produces staining on end-grain protruding on the recurve sections of the violin plates. This is true especially for spruce where the end-grain fibers behave as straws drawing excess colored stain and producing ugly blotches.[4] Greiner’s training as a luthier may have biased his interpretation of Brandmair’s data. However, I found that protein sizes are not needed to prevent blotching. In fact, proteins applied too early in the process prevent color entering the wood.

Brandmair detected casein, egg albumin and/or collagen (gelatin or hide glue) under Stradivari’s varnish. She and Greiner believed that the purpose of the protein was two-fold. First, it can optically wet the wood making fine details discernible and increases the contrast by encapsulating wood fuzz that scatters white light. Wood workers say that sizing makes the wood figure “pop”. Second, the protein controls the saturation of the pore-filling stain that she described as a polar aqueous medium.[5]

Brandmair differs from Greiner in assigning the process order for protein infusion. She explains that the proteins that she detected could have been applied in several different orders and methods.[6] That is, the protein could have been dissolved in water then: (1) rubbed into the wood and followed by coating with the stain, (2) laid over the dried stain on the wood, (3) applied to wet stain on the wood, or (4) mixed with the stain before working this into the wood. I will explain later that I rejected method 1 and now use a hybrid procedure of options 2 and 4.


[1] Karl Roy, “The Violin: Its Making and History”, p. 296.

[2] I owe a debt of gratitude to John Harte for pointing out this evidence with his extensive photographic library of classical instruments.

[3] skim milk, quark a.k.a. farmers cheese

[4] B&G, p. 17.

[5] B&G, p. 22 referred to this aqueous medium as polar which means that it could be water or alcohol, but water is extremely polar.

[6] B&G, p. 61.

 

Personally I think the advantage of using a protein like gel is that it eliminates the glue ghost issue.

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5 hours ago, David Burgess said:

In other words, I don't think that a color alone under UV light tells you much. I would like to see it fleshed out with chemical analysis.

I disagree. It tells you what it reveals. If it looks good and similar to varnish systems that you are striving to copy under different light sources (sunlight, incandescent, led, and uv) you have more sources of validation. If you are not interested in multiple pieces of evidence or do not care to pursue classical Cremonese varnishes then that is a different story. Chemical analysis is another piece of evidence but outside the realm of possibility for almost anyone but a few researchers, especially the destructive tests.. Besides, when the chemical analysis is revealed, many in the luthier community dispute it...frustrating but interesting at the same time.

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