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About lFred

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  1. Hi I've been using old wood and cork violin assembly clamp for ages, I was wondering if some of you have experience with the Herdin , my concern is marks on the varnish.
  2. When I was at the late Jean-Frédéric Schmitt in Lyon, he used to glue one layer of rolling paper on the block, allegedly it would make opening the violin next time easier. While I'm then done it on a few occasions, taking his word for it, I can't tell if it really helps getting the fiddle open, as I never hard to reopen or open a violin closed that way
  3. I love the way you made those interior picture, just a dentist mirror? manual focus on the lens? or camera lens? may I ask what's your setup?
  4. Front (sorry about the non matching color , I'm on a different computer diffrent color space) Was labeled gauché, did not have stamp mark on the wood. I've seen many good one with gauché label, I've also seen mediocre one. but never worse than 'fair trade' . I've seen stamped and labeled, that did not look as good as this gauché. There was a lits of really good hand working for him..
  5. Sure but you wrote "A Léon Mougenot Gauché is a rather basic trade violin at best." We are not talking medio fino or your everyday JTL. But workshop violins made by better luthiers/workers than the one employed at the the big mirecourt factories.. (with the exception of the violin that were made by his apprentice (the child Mougenot was teaching). : ) .
  6. 1) I welcome your suggestions 2) I see your point, the "While you might be tempted to" followed "why it wont work" might not be implicit enough. I could have reinforce by clearly stating "therefore you placing your uv source in the middle of the room will not be effective" Now about safety, this guide was aimed at professional who, use chemical, radiation source, highly volatile and flammable substances machine. Still I do give a fair, bold explicit and graphical warning and go into safety consideration on page 3. ps: not the scope of my article, but about "extreme safety hazard to eyes and skin" . depends what you imply by "extreme" during my research I found that it was relatively safer to use that other type of UV lamp, that the nature of the damages in cwere mostly superficial and not long lasting. (skin burn and cornea damage). I'll refer you to a study made during an accident 90 min accidental exposure to UV-C radiation of 26 medical school students exposed to 700 mJ cm(-2) (in my set up it will means being at 15 cm of my tubes for about an hour) At any rate looking a the blue light of a 20w tube for a few second from a far seems of no concern. Unusual high exposure to ultraviolet-C radiation by Andrea Trevisan 1 , Stefano Piovesan, Andrea Leonardi, Matteo Bertocco, Piergiorgio Nicolosi, Maria Guglielmina Pelizzo, Annalisa Angelini https://pubmed.ncbi.nlm.nih.gov/17205632/ "In conclusion, to the best of our knowledge this is the first report of a number of subjects subjected to a very high and prolonged exposure to UV-C radiation due to a defective switching on of a germicidal Lamp system. Although the total irradiation was 100 or, more likely, 20 times higher than that recommended, only one subject showed severe lesions in the short-term follow-up (2 weeks since the incident). This implies that there is quite a larger-than- thought safety window between the highest irradiation and irra- diation that produces significant damage after acute exposure."
  7. I have seen strait 1 on label (not this label , the usual one) found in several 100% genuine Mougenot Gauché
  8. Btw "gauché" was his mother maiden name. and unlike what it could have been it does not takes root in "lefty" Gauché / Gaucher are local variations of Vaucher / Vaucher / Vaucherot and are of German origin ! coming from come from "Walhari" (walh = foreign + hari = army).
  9. I'll politely disagree some of them are as good as Dieudonné and I would place most of them on par with Colin Mezin Son's based on the father's model. and above CM's son and grand son's
  10. Well even at Laberte/JTL they had dedicated part of the workshop where the best worker made the violin entirely . And they really were factories compared to Mougenot. ps: the label actually looks a lot better than crappy labels found in genuine Mougenot violin.
  11. There is a lot of wide angle deformation in the pictures , It's difficult for me to judge much from those picture, but one thing that I do not like for a Mougenot is the f holes and the huge gap in the area where the "," meant the "I" , (I don't recall the proper terminology)
  12. about the corners, the blocks and the way the c ribs are assembled.. the photo isn't great but.. the close up on the broken corner seems revealing
  13. Now a more direct answer to "feasible and effective". There is nothing special really to my setup: I have in the customer part of the shop a glass display cabinet holding about 20 instruments. the lower part of this cabinet has sliding doors , this is where I fitted 2 uvc tubes connected to a timer, I place violin in between the two tubes. When a customers is finished trying instrument, I put each violin in the "UV box" for 2 minutes².. and that's all there is to it, I have enough space for 2 violins/time. It barely change anything in day to day, as it does not take time and can be done once the customer leave if I chose to. As explain one concern is the ozone generated by the tubes, I did not want to go into those calculations* and therefor advise to use "ozone free" UVC tubes. If you can not (because the only thing that you can find is producing ozone light) I can provide you with corner table calculation, that will be better that the vague (open the window/ after use) recommendation given by the manufacturer of commercial air purifier using ozone generating UVC tube. *because I could not cross referenced sources on the amount of ozone produced by those UV light, and was only able to get the value of (18mg per hours per W) from a an experimental measure. ²based on 15cm between the violin and the tube
  14. Dear Jim, If I understand you correctly, (and summarize to the extreme) you think that: Luthiers don't really care about the why/how and just want to know how make a uv cabinet. Well from my perspective, I did not feel I needed to explain (the intended luthier reader) how to make a cabinet (I state that I'm confident that the reader will make his own clever solution, likely something more clever than the re-purposing a display cabinet that I did). What I knew on the other hand was that information to "set" it right (distance/power/time vs radiation dose & particulars of UVC ) was not available. I had seen colleague mimicking hospital room decontamination , and placing an UV light in the center of the room, with the violin behind glass . Or others thinking of using ultra low power handy devise. Both solution are useless, I tried to provide them with the means to understand why. Now from your feedback , I failed with you. May I ask what causes you trouble ? I've read your recommendations I believe some of them were followed, some weren't and some aren't really applicable, but more to the point I'm really confuse do you recommend more formalism or less? May be I did not understand the beginning of your answer about you wanting something more luthier /down to earth . Regards.
  15. I understood the word "paper" not restricted to formal scientific publication/essay, but also as a text, a column, an article. Since this "illustrated text" was not part of a magazine but a standalone "paper' sent, the usage of "paper" to describe it on this board looked right to me. "illustrated text" sounding a bit generic/weird IMO.. About illustrations they are two one from Encyclopædia Britannica and it is (credited) and the other one from one of the source linked in footnotes. (I should index it more clearly). I do not recall quoting Wikipedia. As far as the first person is concerned, I did not think the lack of formalism from a text initially meant to be read by colleagues with whom I'm having colloquial exchanges would be an issue on a BB with an audience of amateurs and professional of the lutherie where conversations seemed also rather colloquial. You have a valid point a title like "Use of UVC to Decontaminate String Quartet Instruments from SARS-CoV-2" would be long, but more self explanatory and correct (I will keep this in mind). But I think that your suggestion of "String Instruments" falls into the same pitfall as the initial title : I'm not talking harps, electric guitars etc.. Thank you for your feed back.