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Everything posted by Mike_Danielson

  1. 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
  2. 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.
  3. 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
  4. 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
  5. 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
  6. 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
  7. 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
  8. Snark Alert: Does that mean that it is cheaper to do it wrong? Mike D
  9. 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
  10. 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
  11. 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
  12. 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
  13. Do we have any idea where the wood comes from since it is in short supply? I suspect it is from old stumps, railroad ties, fence posts, buildings, etc. Non-ideal sources when you prefer the wood to be split from the log so you can get straight grain. If it survives the bending process, it will probably be OK. Bows are used in an elastic mode; so, they will not be stressed unless an accident occurs (like a kid using it in a sword fight or sitting on it or making a TSA agent angry). regards Mike D
  14. Using GoJo hand cleaner as a varnish cleaner is an interesting idea. I looked up the Safety Data Sheet and discovered that there is more than one type of GoJo. Do you use the Original or the Super Max, for example. The main GoJo ingredient is mineral spirits of about c11 to c15 which is a little heavier than mineral spirits or white spirits. There are stronger detergents in the SuperMax compared to the Original. This is something worth trying (with the usual precautions, of course). I do not understand any mechanism that would harden the varnish, but I could see how you might get that impression. Removal of dirt (mung) would reduce the stickiness, and that might give you the impression that the vanish has hardened. The original formula puts a thin layer of petrolatrum (think Vasoline) on the surface. Mike D
  15. The varnish has imprinted from the textured cloth, only on the back where pressure was applied. Why not on the top since the instrument must have been compressed in the case? I remember German varnishes of this age on cellos that appear to be uncooked, and they suffered from alligatoring. Could this be alligatoring? Jacob Saunders would be a good source of information for this problem (and perhaps what the maker used as varnish--it is likely this was used at the school by others). I would be interested if there is a fix without significantly altering the original varnish. Maybe the best you can do is give it a thick french polish to try and even out the shine/patina. In other words, an acceptance that this is "character" that age has given it. Mike D
  16. You forgot to mention what model is being sent to you. This price is probably the wholesale price, and it is about as good a deal as you are going to get. I have seen 3 cello bows of CodaBow fail in this region, the last one was a colours model. The other day, I rehaired a CodaBow Diamond NX for cello. There was barely room for the standard amount of hair under the slide. The frog was the Xebony plastic material. I did not try to fix this since it would probably damage my tools. This is an amateurish mistake for a company that makes lots of bows. Mike D
  17. I understand Jacob's nostalgia--this is a connection to a family member. I had a Stanley plane from my Grandfather which had a crack starting at the edge of the opening in the sole. Eventually it broke and the plane was ruined. I mourned this loss because I had no other connection with him. My grandfather immigrated from Denmark and started a construction business in Iowa--the business still exists. Newer planes are better, but the old planes are "good enough." Just think about it, the steel in the tools of the masters was pretty crappy by todays standards, but it was "good enough." Mike D
  18. I have seen this failure on old Codabows for the cello, but I have not seen it on the bows for violins and violas. CodaBow sits on this proprietary information in my experience. They are not a bad company, and their bows work pretty well. The OP will have to throw themselves on their mercy--I hope the OP reports back. I like Violadamore's analysis. I cannot see all the detail that she sees but maybe she has a better picture than appears on my laptop screen. Too me, the outer skin appears sunken and implies that the epoxy skin was elongated due a failure (fracture) of the internal fibers. This type of failure is progressive. I suppose an external bandaid would solve the problem (fibers epoxied across the break), but it would look bad, be beyond the skills of most musicians, and probably change the balance point. Probably time to update (and upgrade) the bow. I never gave a thought to the idea that carbon fiber bows had a fatigue life, but this seems to indicate this to be the case. Thanks to the OP for bringing this to our attention. Mike D
  19. Everything about CodaBows is proprietary. You will have to go to them for help. The Conservatory model is ancient; that is, early in CodaBow evolution. The present day warranty is for the original owners. Are you the original owner? I suspect there is no warranty for you, but it does not hurt to ask. I think there is an internal reinforcement in the old CodaBows at that location--perhaps a pin or rod. There is no repair for this that I am aware of. I would just keep playing with it until it breaks off or becomes unplayable. Mike D
  20. This subject comes up, periodically. Here is an old thread on the Zaret bass bar, the most extreme bar I have ever seen: https://www.violinist.com/discussion/archive/12622/ I have seen early Zaret bass bars which are about 25 mm tall the entire length--how about that. So what is the role of the bass bar--I think it acts as a support (fulcrum) for the bridge, and it does not need to be massive. I do not know the best dimensions., but the existence of the Zaret bar indicates a lot of variation is possible. I do not think bass bars get old and on the basis of that need replacement. Wood keeps its mechanical properties for many many years. Mike D
  21. Chemist here: The rosinate is a salt. The purpose of cooking the oil and rosin is to achieve a chemical reaction between the oil and resin. A polymerization reaction. Cooking at 120 C (as Jackson reports) is not a very high temperature to achieve the polymerization, but I cannot say it is impossible if it is maintained for a long enough time. The traditional Michelman varnish is a complete failure as Don Noon states. John Masters lives in Cincinnati and has seen the old instruments with this varnish, and has reported on it on Maestronet. Good luck with this topic Mike D
  22. I just got on the VSA website and discovered there is no Table of Contents for "The Scroll." Is there any way we can see the Table of Contents for the most recent journal (as well as the earlier issues)? Mike D
  23. Fred, I would like to see a picture of this stuff. I know you are aware of the history of black oil, maroger's medium, megilp, etc as mediums in the oil painting world.; so, I will not say any more. Have you considered transparent yellow pigments such as W&N transparent yellow? This could be added to a thick linseed oil and rubbed on the surface to enhance the yellow-ness of the ground as well as seal the wood. There are a bunch of transparent and semi-transparent pigments of various yellow hues that would also work since you are putting them directly on the wood. Disclaimer: this is not Strad's or Amati's ground--It's Fred's ground. Mike D
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