Brian McLinden Posted February 25, 2011 Report Posted February 25, 2011 Let's all go for the fences. One thousand years of longevity. I'm trying to engineer a viable modern ground system from scratch. The Cremonese have already had their day! Too bad they didn't have journals, MN, and, for example, wetting agents! So I'm not trying to imitate the Cremonese makers with respect to their ground materials and practice, but simply to learn how to think about the general ground problem, which they presented to us without accompanying theoretical statement or commentary. What should “grounding” do that “varnishing” can't do? Can we ground a plate by applying a “one pot” concoction, preparation or solution, or is a systems approach required? Are multiple bench operations and/or thin films or layers required? Why or why not? I've seen materials lists and discussions of oil-resin emulsions aplenty, yes – but I've not seen this general question of ground rationale and theory thoughtfully confronted in our journals, at least from a bench or craft perspective. What corners of the journal literature may I have been missing? A woodfinisher would ask violinmakers this: why bother to figure out theoretically this matter of grounding? What do you think theory will do for you? How does it govern your practice? If you say you respect ground theory, why haven't you published more about it in your violinmaking journals? Why are university chemists and physicists doing all the writing nowadays? Are they turning out any useful ground theory that you can apply? An engineer would ask violinmakers this: what should a grounding system accomplish with respect to your requirements and constraints? Suppose you are alive 300 years ago and you know there is more to your craft than using old patterns and carving, scraping and brushing. What were, or what could have been, your own theory, objectives, requirements, and constraints – as opposed to your supposed materials list – to guide you in your grounding practice? Varnish theory has been much discussed, but I would be keenly interested to know where and to whom one can turn for help where ground rationale, grounding theory, and grounding procedure are concerned. Maybe it's time someone wrote a book on the subject. If you have private thoughts on how our field and current paradigm is functioning with respect to ground theory and practice, I'd welcome corresponding with you, of course held confidential. Brian.McLinden (at) gmail (dot) com. Though I'm only self-taught in chemistry and silicate materials science, I'll try to follow what any theorists and bench people have to say about ground vs. varnish. What should “grounding” do for you that “varnishing” can't do? As a woodfinisher I may have insights to contribute.
Bill Yacey Posted February 25, 2011 Report Posted February 25, 2011 The problem is nobody fully understands what is required of the ground. Sure, visually we want this look and that effect, and we want it to stop the colored varnish from soaking into the wood. However, mechanically and ultimately acoustically, what role does the ground play? If we knew, then we could look for some substance to meet all the desired requirements. Most of what we think we know is speculation and conjecture.
violins88 Posted February 25, 2011 Report Posted February 25, 2011 Ok, I am only an amateur, but I will take a stab at answering. Martin Schleske wrote that damping should be minimized. I know there is disagrement here, but that's ok. So, to minimize damping, you don't want oil in the wood. According to Harris, the emulsions help this situation, placing the matter on the surface, keeping penetration to a minimum. I suppose that helps minimize damping. I am currently playing with casein and venice turpentine.
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 The problem is nobody fully understands what is required of the ground. Sure, visually we want this look and that effect, and we want it to stop the colored varnish from soaking into the wood. However, mechanically and ultimately acoustically, what role does the ground play? If we knew, then we could look for some substance to meet all the desired requirements. Most of what we think we know is speculation and conjecture. Thanks for weighing in, Bill! Grounding theory needs the onset of creativity. Let's bring ground practice into the 21st century. Creativity, and not a little professional courage, must arise from the bench, not the university. I'm thinking that a lot of posturing and smugness is masking that much needed speculation and conjecture on this forum. Perhaps it is even a stifling or inhibiting influence, privately at least for would-be posters. Good engineers cannot function without speculation and conjecture. In another thread, "on requirements for a "Cremonese" ground system," I suggest that oil-proofing is a requirement for the ground system. Do we really want oil varnishes to penetrate into the wood? What happens if we allow that? How can we keep wood chemically inviolate, for longevity of the instrument, yet achieve what I call an "elastic trampoline" for the ground system, as I've implied is a good idea?
MikeC Posted February 25, 2011 Report Posted February 25, 2011 I'm going to try numerous thinned coats of shellac because I think it will penetrate into the upper layers of the wood and will be hard and durable and will therefore protect the wood while at the same time preventing the color oil layers from penetrating the wood. And it will give a golden amber color tone under the main varnish
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 Ok, I am only an amateur, but I will take a stab at answering. Martin Schleske wrote that damping should be minimized. I know there is disagrement here, but that's ok. So, to minimize damping, you don't want oil in the wood. According to Harris, the emulsions help this situation, placing the matter on the surface, keeping penetration to a minimum. I suppose that helps minimize damping. I am currently playing with casein and venice turpentine. Thanks, Violins88! Why not try borax, casein, and shellac? I thought about rosin and turpentine a while ago, but no percentage. Plant oils are chemically unstable. Who on earth would need them in a ground system adjacent to the wood, which system should promote longevity? Who wants to introduce (wood, coating) burnishing as an important craft operation in grounding?
Michael Darnton Posted February 25, 2011 Report Posted February 25, 2011 What indication do you have that they thought longevity was important?
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 What indication do you have that they thought longevity was important? I don't care what "they" thought. I'm saying, and so is Burgess, that longevity is crucial for a modern instrument. Are you not interested in instrument longevity for your clients and their heirs??
Michael Darnton Posted February 25, 2011 Report Posted February 25, 2011 400 years seems long enough to me.
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 400 years seems long enough to me. Let's go for a thousand years, eh? What are you doing to control moisture content? Is this not a requirement for the ground system?
Bernhard Ritschard Posted February 25, 2011 Report Posted February 25, 2011 What are you doing to control moisture content? Is this not a requirement for the ground system? What about the inside of the instrument?
MikeC Posted February 25, 2011 Report Posted February 25, 2011 Let's go for a thousand years, eh? There are oganic objects with pictures painted on them that are 1200 years old and still in fairly good condition without a ground coat. Book of Kells 800 A.D. So is a ground coat really necessary for wood protection / preservation?
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 What about the inside of the instrument? Now you're thinking! An inside treatment can slow the rate of moisture change, though hardly change the equilibrium level of moisture content. Now I'm speculating - an inside treatment (say, for example, borax, shellac and casein), could change how air moves around in the chamber.
Philip Ihle Posted February 25, 2011 Report Posted February 25, 2011 I like your eloquent approach and your determinedness Brian! Let me add a second point to your list off requirements: show the beauty of the wood at its best. I spend many hours in choosing a piece of wood and in cutting it at the most appropriate angle, I want to make the most of it and know that the ground can enhance it's natural beauty ny showing the pores and midolary rays on the maple and the grain on the spruce. Could you please explain me, why you think oil does not protect the wood for a 1000 years and why you suggest a complicated mixture of Shellack, Borax and casein - what makes the mix of the three a better sealer than, let's say, casein alone? Philip
scordatura Posted February 25, 2011 Report Posted February 25, 2011 My ground criteria are: Refractive index similar to wood Strengthens wood Minimal Damping Penetrates wood Golden Color Allows varnish to adhere (or not if you want the varnish to chip off if you want the instrument to look old at some point down the line) Stabilizes the moisture content of the wood Isolates varnish from wood Good surface "wetting" properties so that the grain is enhanced
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 I like your eloquent approach and your determinedness Brian! Let me add a second point to your list off requirements: show the beauty of the wood at its best. I spend many hours in choosing a piece of wood and in cutting it at the most appropriate angle, I want to make the most of it and know that the ground can enhance it's natural beauty ny showing the pores and midolary rays on the maple and the grain on the spruce. Could you please explain me, why you think oil does not protect the wood for a 1000 years and why you suggest a complicated mixture of Shellack, Borax and casein - what makes the mix of the three a better sealer than, let's say, casein alone? Philip Hey Philip! Oh yes, orienting the wood properly is undoubtedly crucial for aesthetics! Folks, can the ground contribute more to tonal and optical beauty than the wood itself? I believe it can, so I lay awake nights. . . . Plant oil is chemically unstable. Period. (Maybe castor oil isn't.) But why concern yourselves with the dynamics of polymerization and and worry about eventual mechanical degredation over time? Possibly an emulsion of a petrochemical oil or grease might not be curtailing of longevity, but who would suggest that, and for whatever reason? Borax, shellac, casein - a coating less rigid and much more elastic than casein and borax alone. Who needs rupture of the wood? Throw in a little hide glue if you want.
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 My ground criteria are: Refractive index similar to wood Strengthens wood Minimal Damping Penetrates wood Golden Color Allows varnish to adhere (or not if you want the varnish to chip off if you want the instrument to look old at some point down the line) Stabilizes the moisture content of the wood Isolates varnish from wood Good surface "wetting" properties so that the grain is enhanced I've heard it said that identical refractive index promotes transparency and the throwing about of light - but I'm not convinced; Lay on a lead silicate and you'll have questions... Why don't we all use wetting agents?
NewNewbie Posted February 25, 2011 Report Posted February 25, 2011 What should “grounding” do that “varnishing” can't do? Unless "grounding" is "varnishing"???? J.P. Echard and his team found ... "“Although the five instruments were produced over a period of three decades, their varnishes are very similar,” explains Echard. “Stradivari first applied a layer of an oil comparable to the oils used by painters of the same epoch, without fillers or pigments to seal the wood. We did not find a mineral-rich layer, as some earlier work suggests. The master violinmaker next applied a slightly tinted oil-resin layer. We have detected nothing that would have suggested the use of protein-containing materials, gums, or fossil resins.”" - Secret behind the composition of the varnish on Stradivari violins revealed My guess is that if things remain the same, museum-wise, then 6 or 7 hundred years from now, the instruments will still be 'sound', unless this heads the museum!!!
NewNewbie Posted February 25, 2011 Report Posted February 25, 2011 Now you're thinking! An inside treatment can slow the rate of moisture change, though hardly change the equilibrium level of moisture content. Now I'm speculating - an inside treatment (say, for example, borax, shellac and casein), could change how air moves around in the chamber. And in re-graduated instruments, with studs sticking out?
scordatura Posted February 25, 2011 Report Posted February 25, 2011 I've heard it said that identical refractive index promotes transparency and the throwing about of light - but I'm not convinced; Lay on a lead silicate and you'll have questions... Why don't we all use wetting agents? I think the concept is to allow transparency. The ground should not obscure the wood.
lvlagneto Posted February 25, 2011 Report Posted February 25, 2011 Ground prevents varnish color from reaching the wood and being drawn into the fibers. Sometimes pigments can be drawn in unevenly, causing a blotchy look. Cooler browns and reds ten to be more opaque, while warmer colors are more transparent (pretty big generalization, but for browns and reds, this seems to be true). If you plan to varnish a violin in a fairly light color, I don't see the need for ground.
Michael Richwine Posted February 25, 2011 Report Posted February 25, 2011 Folks, can the ground contribute more to tonal and optical beauty than the wood itself? I believe it can, so I lay awake nights. . . . I wouldn't say it was more important than the wood, because you have to have a well made instrument before the ground matters much, but we routinely use the ground to modify tonal characteristics. We've been experimenting for over 15 years, making incremental changes in our ground formulas, and sometimes tiny changes in formulation can make shockingly large tonal changes. I wouldn't have believed it until I saw for myself. Ground can also make quite a difference visually.
NewNewbie Posted February 25, 2011 Report Posted February 25, 2011 You need to do some experiments on your own to determine the qualities that you wish to provide/enhance with your coating system. I say this because everyone has a different set of criteria for their coating system, and as such go about things in a 'goal' orientated way. This link gives a nice picture of how Martin Schleske went about answering the very same questions you are asking. Martin Schleske A spin off of Martin Schleske's approach by David Meyer in this link. www.meyerviolins.com You mentioned casein. Emulsion ground for stringed instruments Lots of information on grounds, primers, sealers here. www.classicalvarnish.com
Brian McLinden Posted February 25, 2011 Author Report Posted February 25, 2011 Unless "grounding" is "varnishing"???? J.P. Echard and his team found ... "“Although the five instruments were produced over a period of three decades, their varnishes are very similar,” explains Echard. “Stradivari first applied a layer of an oil comparable to the oils used by painters of the same epoch, without fillers or pigments to seal the wood. We did not find a mineral-rich layer, as some earlier work suggests. The master violinmaker next applied a slightly tinted oil-resin layer. We have detected nothing that would have suggested the use of protein-containing materials, gums, or fossil resins.”" - Secret behind the composition of the varnish on Stradivari violins revealed My guess is that if things remain the same, museum-wise, then 6 or 7 hundred years from now, the instruments will still be 'sound'. NewNewbie, I don't care what Stradivari did. And I would not like to speculate what the "Messiah" will look like in another 700 years, even under glass, which is not fairly representative of playing conditions. I concern myself only with the shifting and perhaps evolving reasoning that he and peers like Bergonzi used to ground their plates. Then I want to us improve upon this reasoning, to the extent that it is knowable and we can somehow do this. I'm convinced that unknowingly one can introduce chemical time bombs like oily or highly alkaline or acidic chemistry into the wood that make longevity an utter fantasy. Burgess, at his website page on "varnish", is aware of this. I don't believe Echard is a violinmaker or even a wood finishing expert. His findings represent just more of the same that we've seen for the past 20 years. His instrumentation is not a help to our reasoning.
Bernhard Ritschard Posted February 25, 2011 Report Posted February 25, 2011 You mentioned casein. Emulsion ground for stringed instruments Who is Charles Hargrave? Is he the cousin of Roger Beare?
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