nathan slobodkin

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Everything posted by nathan slobodkin

  1. I knew if I kept reading this thread somebody might say something interesting. I have heard of equal tension stringing but don't really understand how that worked and what is the advantage (or not) of our current thinking on string tension.
  2. David, I also seldom see instruments open up while actually in my shop and I think perhaps never on my own instruments between manufacture and sale. However I certainly do see a lot of instruments come in for open seams especially in late winter which I refer to as "cello cracking season". I tell clients that unless they have an accurate hygrometer and modify humidity according to what it tells them then they will frequently need to have their instruments reglued.
  3. Actually that is exactly what I was suggesting
  4. The same principles apply to openings in the back but because the wood is less prone to cracking the glue can be stronger. If all is working right the back should be glued well enough to encourage adjustments to occur on the top joints.
  5. Yes. As a beginner I would caution you that rasp marks can go deep and you might want to leave 1/2 mm to smooth with a file and scrapers before carefully sanding down to 400 grit sand paper.
  6. It takes hours for wood to pick up and release water so if the instrument is in a proper humidity while being stored that is usually enough to prevent serious damage. Not a bad idea to soften the blow a bit by getting to venues early enough to let the instrument sit in the case for a few minutes if you are taking it from a very cold outside temperature to a warm inside one. I don' t worry much about instruments which get small openings of the top when the weather changes as long as you get them glued up imediately. I do worry about instruments which never open up despite severe stresses as they may eventually crack. Arching shape and other factors have a lot to do with the stability of an instrument and some experience is needed to get the gluing right so that it holds well but lets go before damaging stress occurs. By the way I truly hate dampits and generally reccomend controlling humidity in the storage and practice room rather than in case humidity gadgets.
  7. On a nice fiddle a one piece new edge with underlayed doubling would probable be best. I'd redo the purfling after gluing the new wood but before finishing the edge and bring the new purfling well past the new wood to avoid drawing attention to the joint. This fiddle may not be worth the trouble however. If there is enough wood left you may be able to add a doubling on top of the remaining lower edge and then replace the purfling.
  8. There are definitely issues with using any other glue but normal hide glue in violin restoration. While there are uses for the glues you mentioned crack repair is not one of them.
  9. Thanks for posting this. It is extremely interesting although I doubt it will change how I graduate instruments. My thoughts on graduation are pretty simple. The instrument has to be strong enough not to collapse, flexible enough to vibrate and not too heavy. Both arching and wood properties affect all three as does the model so it is really impossible to make firm rules about graduation thickness. In general my backs have a thinner area as a ring shape following the outline but distance from the edges is variable. Tops usually have some sort of thinner "lungs"in the outer bouts and a slightly stiffer beam down the center for strength. Bass sides slightly thinner than treble and accommodation made for any slanted grain orientation. All wood is different and different people want different sounding instruments so following the basic principals at top of the paragraph work for me and I haven't had a real dog in about 35 years and that one eventually sold any way.
  10. Moving the post in also lessens the tension on the instrument and would basically "turn down the volume" . This can be easily confused with "mellower". Having said that it is also possible that your luthier did indeed achieve what you wanted and that the effect will last.
  11. And the winner is....... Go Practice. Congratulations job well done!
  12. One thing you didn't mention is the age of the violin in question. You say the purfling looks good but if this is an old instrument you might try putting a thin drop of water onto the purfling and then pressing on the plate enough to flex the edge. Sometimes you will see the water being sucked in to the the purfling channel which obviously indicates it is loose. This usually causes the buzz to stop temporarily so be sure to mark the spot so you can apply some thin glue there once it dries out. You may also see air bubbles which also mark a problem area. I go all the way around both plates in this way as often there will be more than one spot buzzing at the same time. The most common area to see the loose purfling is in the c-bout area especially if there are lower wing cracks even if they have been repaired.
  13. As you realize there are myriad possibilities and even very experienced people (like Mark) can spend days looking for them and still not be sure they have solved the problem. My own approach is to eliminate every possible external cause about three times over before considering internal causes. The actual sound of the buzz is really important and there is no way a description will help. Experienced luthiers can sometimes get a clue from whether the buzz is metallic, a rattle, a hissing....... There are also procedures of applying water which can sometimes pinpoint loose purfling, loose peg ornaments, loose tailpiece frets etc. If the problem is internal you have a whole other set of issues ranging from a bead of dried glue all the way through loose linings, problems with previous repairs and the ever popular but very, very rare loose bass bar. It sounds like you may have done all that can be done from the outside and that the instrument will have to be opened. Assuming this is a pretty good violin the only person taking the top off should be an experienced, professional violin maker and if you are going to have that done then you might as well have them go through the external stuff again beforehand because they may find some thing you have not seen. Good luck! There are no easy answers here although invariably when you find it you will think "How could I have missed that! ".
  14. Brad, I actually do the complete rehair including the ferrule wedge before wetting and if needed use a hair drier to allow me to give the bow back within the hour. I figure the hair will stretch a bit and generally rehair as short as possible in the winter and just slightly longer in summer.
  15. I rehair dry then tighten the hair FIRST and then wet it and let it dry. No way the hair can dry tighter than it already was so no possibility of damaging the bow. if the hair looked decent when you haired it dry it will look even better after being wet and allowed to stretch and even out. There may be a hair or three that doesn't shrink up all the way and I just take those out rather than messing around with flaming or what not.
  16. Planes just like any tool are not ready to use straight out of the box. Most apprentice craftsman could benefit from signing up for a night class in machine tool technology at their local high school where they can get access to a precision grinder. You can flatten the back sides of your chisels and plane blades as well as the soles of your planes. When you grind the planes make sure that the blade is tightened in cutting position since the casting bends slightly when the blade is locked down. I also found it helpful to put a narrow slip of tracing paper across the center of plane blades between the blade and the magnetic chuck so that the blade winds up with a slight lengthwise hollow so that when the blade is laid on the stone it presses down hard on the leading edge. Metal castings take years to cure. The best tool makers allow the castings to sit for years before machining but they can still warp years later and must be reground or touched up with a hand scraper. There is something to be said for wooden planes in that while they may need retuning more often the job is easily accomplished with basic woodworking tools. I believe it took me about 3 hours to tune up my Ulmia jointing plane when I got it and haven't had to do much to it for the past 35 years. You can buy precision straight edges guaranteed to be accurate within less than a thousandth of an inch from machinist supply houses.
  17. I am having a hard time believing that wood shrinkage alone is causing your problem but it does sound strange. How old was the wood you used and what kind of treatment did it get since it was cut?
  18. If the end grain is sealed before coloring then as the neck wears it will reveal a ring of lighter colored wood at the edge of the varnished area which cannot be stained because the grain is sealed. If the color is applied first the color remains consistent as the neck wears and if any reshaping is required more color can be easily blended in. With a new neck or a neck which is being reshaped completely including stripping the heels then I apply a size after the color but before varnishing. Several very extensive discussions previously on MN about neck shaping and finishing.
  19. I am really not trying to be rude but if someone is having trouble with this basic task I would suggest finding some one who knows how to do this and asking them to show you. Once you have a solid bench and a properly set up plane with a sharp blade this job should take less than 1/2 an hour and there should be no "stress" involved. That includes flattening the inside sides of the wedges. If the actual planing of the joint takes more than a couple of passes then invariably something is wrong with the plane that must be addressed before continuing.
  20. Yes if you want it to arrive somewhere intact that is possibly OK. If I am shipping to a client however it doesn't do them much good if it isn't playable and trusting a competitor to set it up is not usually a good idea.
  21. David, This relates to your comment from a different thread about my reluctance to ship cellos. Custom made and oversized? Any chance of getting more info that might help me have something made which will enable safer delivery of cellos during the current crisis? Safer both for me and the cellos that is.
  22. Good points. i certainly prefer to talk on the phone to work out what will be done, point out extraneus condition issues, set up appointments and estimate charges. I then ask the client to send an email to "remind me" of what was discussed on the phone which gives me a record and avoids misunderstandings.
  23. I also doubt that will happen since you seem pretty happy with the method you are using . While it is always possible that some one will improve on centuries of accepted practice it is usually accomplished after long experience. Since violins generally last longer than humans it pays to look at historical methods rather than limit one self to what you can see works for a short time. It is quite possible to discover too late that things you thought very clever at the beginning of your career had some unforeseen negative consequence.