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Mike_Danielson

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About Mike_Danielson

  • Birthday 10/22/1942

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    Richland
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    Materials scientist--PhD

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  1. Thanks James and Violadamore for bringing this paper to my attention. I read it a couple of times. Yes, adding pumice and/or bone ash have a very beneficial effect on speeding up the drying but it is not any faster than adding lead driers--this is useful to know. The big surprise for me is that their analytical techniques were applied to over 30 different musical instruments. And the varnishes all had a similar composition--all based on a drying oil and resin from pinacea treas. This is additional confirmation of the work by Echard and many others that there is a consistency to the resuts. The particles in the historic varnish seemed to resemble pumice. Since they found phosphorus, that seem to be the driving force for thinking bone ash was added since that is a possible source. I suspect it could also be a contaminant that is present in the pumice, rock, or whatwas added to enhance the varnish coor. When the authors made there own varnish, they reached for linseed oil and pine resin. Cooked at 220 C for 6 hours. The varnish was extremely light colored. We know from other outside data that you have to cook it at a higher temperature if you want a dark red-brown varnish. The authors took a look at historic varnish recipes before they made their own; such as, the De Mayerne recipe and Strassburger manuscript--they did their homework. Anyway, I like the paper, and as time goes on, we will get an even better understanding of what the masters (there were a lot of them) were doing. My surmise is that it will be something simple and practical--no secrets. Mike D
  2. Roman, give the customer what he(she) wants. No lecture. Here is how I would do it: 1. Seal the wood--I would use several coats of dilute fish glue. 2. Use your least colored varnish varnish and put enough coats to completely seal/fill the wood. Rubbing on is probably enough. Your goal is to not allow the black to penetrate the wood surface. 3. Get a can of black spray paint of your favorite black. I would go with a semi-gloss. Mask off what should not be coated and put on several thin coats until color is uniform. 4. Finish with 2-3 coats of you least-colored violin varnish. For the neck, I would use black Transtint dye followed by french polish. I like these types of problems Mike D
  3. This product from Kremer is essentially pine resin or rosin dissolved in turpentine. You could make your own or even dissolve rosin in alcohol for a similar product. In any case, the solvent evaporates leaving the rosin behind. Some varnish makers offer a balsam ground which is probably similar to the Kremer product. In the short term, it is not going to dry by polymerization like an oil varnish does, but it will appear to be dry to the touch. Better try it to see if you like it. It would probably work as a substitute for sealing the bare wood by use of a protein such as glue. There is a lot of analytical chemistry work that suggests a protein sealer was often used. Mike D
  4. I think the world is ready for a new cello case design. I am talking about one that protects the instrument from the neck snap when the case falls over.
  5. Jackson has an extremely high regard for the varnish book by JG McIntosh. I looked in the book and I can find no instance where he makes an iron rosinate--that is strange since it is such an obvious thing to do. The rosinates made using cobalt , lead, and manganese, for instance, are used in small quantities as driers. Mcintosh makes mention of a cheap varnish using some kind of rosinate--I cannot remember the metal ion used as the rosinate salt. I cannot find any reference in the varnish making literature where the entire amount of rosin to make a varnish is presented to the linseed oil as a metal rosinate salt. In other words, the varnish is a cooked metal rosinate with linseed oil. I do not know the significance of this difference, but it is greatly different from the traditional making of a cooked oil varnish. Merrifield's recipe calls for only a small amount of alum to be added (size of a nut). My suspicion is that the rosin combines with the linseed oil by esterification during the heating process. With a standard rosin and linseed oil, the ester releases water which just evaporates from the hot liquid. With a total metal rosinate, a calcium hydroxide, zinc hydroxide, sodium hydroxide etc (it depends on what metal ion is used with the rosinate) is left behind in the varnish. I do not know if that product will continue to react with the varnish and have some later, long term effect. In particular, will the iron rosinate be color stable over time. ASTM has methods of testing varnish aging and color stability. I think you have to be very careful when beating the drum for a new method of varnish making that may have future problems. Be careful. Remember megilp and its dreadful effects. The initial response for megilp was enthusiasm. You can still find people that like it. I think Michael Darnton likes using a varnish for violins that is megilp--but maybe his thinking has changed. Mike D
  6. Rosin or balsam as a ground is not the same as linseed oil. At least linseed oil will harden as your chest of drawers shows. If you are using the rosin or balsam in small amounts as the ground, then why not use varnish in small amounts as a ground because it will fully harden in a short time. The refractive index is probably about the same for all these. Mike D
  7. I was thinking about the use of rosin or balsam in an alcohol or turpentine medium as part of the ground since some of you advocate it. Looking at the main molecule, it is clear that rosin does not polymerize; so when you apply it to the bare wood, it penetrates the wood and sits there after the solvent evaporates. Is this a good thing? Are there any long term negative consequences? Rosin will form an ester with linseed oil and the linseed oil has the unsaturation that allows polymerization to take place which causes the varnish to dry. Mike D
  8. The varnish experts and makers become cagy in telling us what they do. It is always this way. I enjoy the comedy. Don Noon gives us the essential features of what the varnish system must consist of. I would add that the process must be simple. Davud Beard has included a very useful paper by Fiocco. His team (Fiocco's) has published several recent papers including a couple using the OCT method. The direction of research has moved from Echard to Fiocco. The enclosed paper is of an Andrea Amati cello with a gypsum ground, some colored particles over that, and then the varnish which has some colored particles. Other Fiocco papers indicate a protein in/on the wood. It is all fairly simple when you get down to it. There are a few makers, like Hargrave, that will tell you everything that they do. Most makers get a coughing fit when asked to reveal what they do. Mike D
  9. The beauty of the Heet pot is the temperature control. The devices respondents suggest cannot be left on; so, they are not a solution. Go to ebay and search for PID temperature controller. Lots of devices to chose from for less than $50. You may need a solid state switch or maybe not, depending on what type of switch is inside the controller. Pay attention to the power needs of you heating element in the glue pot--remember, this is an inductive load. You will need a thermocouple to sit inside the pot (water side). You will need to do some simple electrical wiring and probably put the controller in a box. Mike D
  10. Snark Alert: Does that mean that it is cheaper to do it wrong? Mike D
  11. If washing the lake does not work, then the problem is likely due to a contaminant. The OP does not appear to have great chemistry skills. There is not a lot that we can do to help him. I suggest that he purchase the stuff from Kremer. For your general information, all fats and oils are organic acids. The measurement of pH is meaningless for this situation since they are not soluble in water until you react them with something like sodium hydroxide--then you make a soap. The attempt to finish a musical instrument is filled with chemistry issues. And from my observation on this website, most of you have never taken a high school chemistry course. This presents a real problem for success. The products that everyone wants to use are those of Koen Padding, but he died without leaving a recipe book. Thanks to a few of his friends, we have figured out a couple of his recipes. Hargrave and Michetschlager have contributed to our present understanding. The power of the modern pigments is that they are color-fast and often more transparent. Chocineal lakes, Madder lakes and even of some of the varnishes (mediums) such as megilp are unstable. It is a mystery why people are attracted to this stuff that fails the test of time because it is going to eventually fail for them, too. It would be nice to know what the original varnish looked like. Mike D
  12. Ka-Boom! This topic has exploded. Peter K-G innocently used the word "retarded." Anyone read the papers that John Hart posted? There is a new technique that is BIG! OCT--a method to image layers and particulates without damaging the varnish. The instrument of interest is a Storioni. And yes, a protein layer is observed adjacent to the wood and a particulate layer over that. The analyzed site is under the fingerboard. It is probably too late to salvage this initial topic--too bad. Mike D
  13. Kremer sells the stuff, and it is red in the pictures. There is the possibility that you have not washed your lake well enough. Brumcello's comment nailed it. The color is fugitive, but you probably already know that. Mike D
  14. Edward Heron-Allen is the definition of the autodidact. His book reflects the knowledge of violin makers of this age. If you read the book, you will realize that Heron-Allen is detailed and through. You will find the book interesting, and wow, look at the comments throughout the book--what a breathe of knowledge. By today's level of violin knowledge, the book is dated. Mike D
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