nathan slobodkin

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Everything posted by nathan slobodkin

  1. I agree with Ben on this . The linen seems to make no difference in sound so if the ribs seem weak for any reason extra thin, extra flamed or weaker wood like American poplar or willow then I use the linen . You should be careful about how you use it however. The linen doesn't cover the whole rib but is done in strips about 50 mm, wide which run from the center of the linings and across the rib. If the cloth ends at the lining it may lead to cracking along the edge of the lining and if you cover the whole rib you can get warping and it may affect the ability of the rib to vibrate. One other hint is to use reasonably thick (normal) glue to glue the cloth in as if it's too thin especially on flamed maple the glue could bleed through the rib and leave shadows on the outside when you varnish.
  2. If you intend to sell this cello I think you owe it to both yourself and your client to get this joint right. The center joints are the basis of the instruments structural integrity and if the ends don't fit I doubt the center is really right either. There has been some discussion of center joint making technique in a recent thread on this forum which you might benefit from reading. My own method which I have used successfully on hundreds of instruments is to plane the joint very carefully to have a very small opening in the center which gradually gets smaller until the ends fit tight. The space is about 1/2 MM in the center and must be closable with one clamp in the center tightened using two fingers to turn the screw. I also put the lower half of the plate in a vise and try to rock the top part across the corners if it rocks I adjust the fit until there is no wobble what so ever. Finally I take a strong portable light and shine it along the joint and look at it with a loupe to make sure there are absolutely no gaps of any kind. After fitting the joint I glue with fresh strong hot glue just thin enough to squeeze out of the joint and run down the outside in thin streams when clamped with three clamps tightening the center clamp first. My first teacher told me many times "if it's not right do it over" I have regretted every time that I ignored that advice.
  3. This sounds potentially clever Martin. Could you explain exactly what you are doing?
  4. Does anyone have any idea who was making bows stamped Gemunder and sons? I think the one I just saw was 1900 to 1945 . Were any of the Gemunders actually bowmakers? Bowmakers in the shop? Or just imports with their stamp? Niceish German looking bow.
  5. Yes, you should get a receipt or claim check. In my shop I use a string tagged ticket with a tear off receipt and the tag stays either on the bow or in the parts tray while the bow is actually being worked on and is reattached to the bow before it leaves the bench. My assumption is that someday the executor of my estate will need to identify any property in the shop belonging to others and I act accordingly. You should also expect that any old fittings , strings etc. which are removed from your instrument during servicing be returned to you. I put all that stuff in a bag with the clients name on it and put the bag with the similarly labeled case any time the instrument is being worked on.
  6. Using machines for this job can lead to a lack of fluidity and an awkward transition between the edgework and the arch. After rough arching I use a slitting gauge to mark the edge thickness at 3.8 in the bouts 4.3 in the C and 4.8 in the corners and the button of the back. Then I arch the plates closely as I can to the final shape with gouge and planes and run the arching gouge around the edge leaving the outer edge just enough above the marked line that I can run a small flat bottom arching plane around the perimeter planing down to the final thickness. As a last step before marking the purfling I run a small round bottom arching plane around the inside of the perimeter leaving a flat area from just inside where the crest of the edge will be and lowering the area where the channel will be to save a bit of work cutting the purfling. After purfling the channel only needs to be gouged down another half mm. and the arch blended to the channel and scraped. The time from the rough arched stage to finish arched, purfled, channeled and scraped is usually two days work for a set of violin plates.
  7. While most players will not object to a slight variance in string length the relationship between the string length and the neck are more critical. If the left hand slides up the neck to fifth position the first finger should be in tune when the thumb hits the heel of the neck. If the hand is pulled out of position when shifting that is going to be a problem.
  8. Softer maple will generally give a darker sound and if it is also light in weight you can adjust grads to suit your needs if it's heavy however that may be a problem. I would be careful using softer wood for necks however as it is often less stiff as well.
  9. Melvin would you care to elaborate on this? I have seen and made both fairly rough and quite smooth surfaces using only scrapers. If one raises the grain several times and rescrapes the ripple can be much less pronounced. Like wise scraping and then using some sort of stiff leather or even a wood block with abrasives can give either a flat surface with the hard reed slightly depressed or a completely flat surface. What I don't see in the old stuff however is the look one gets with oversanded surfaces where the soft grain shrinks below the hard reed over time. Am I wrong about this? I guess I am unclear what you mean by a "modern" scraper finish as opposed to an ancient one.
  10. Thanks for your help folks Armed with the knowledge that the non head part of these are indeed not tapered I was able to remove them with a combination of tapping, pulling and swearing at the inventor. problem solved.
  11. Conor, the problem is that they are made of brass and wood sandwiched together cutting them off would be another nightmare which I am certainly trying to avoid but if it has to be.....
  12. I think you have answered my question. You are saying that the part inside the pegbox is not actually tapered? They definitely seem to get tighter as I try to move them in the direction away from where the peg head would be but perhaps this is only that the peg has worn slightly where it contacts the wall of the box. It certainly makes more sense if they can be removed in that direction but I've been reluctant to hammer on them. I'll look at the little bastards again this morning. Once that part of the peg is out there is no problem but of I cant get them out it will be a nightmare.
  13. Has anyone else had the misfortune of dealing with Caspari pegs? I have successfully avoided these for many years but now am working on a nicer instrument that someone has installed these contraptions on. The problems include that of course they don't really work well while being large enough that a complete bushing job and new pegs would be required if I take them out. That is bad enough but the other problem is it is not obvious to me how to get them out if I need to. They seem to have a glued in Fiber bushing with the mechanical part of the peg on the pegbox side inserted before the bushing is glued and then the peg head locked onto the turning part with a slotted mating connection and tightened and adjusted with a screw. The problem is that the turning part in the pegbox seems to be tapered just enough that it can't be removed except by sliding it toward the bushing this means the only way I can see to remove these is to some how loosen the glue on the bushing and then drive the whole peg out toward the head side as if loosening a stuck friction peg. since loosening the glue with no way to rock, twist or otherwise move the bushing seems difficult at best I am thinking that no one could have been so stupid as to design these this way. What the heck am I missing?
  14. In my experience the wood doesn't return to its preglued shape, The wood is "frozen" in the swollen state by the drying of the glue. I have seen this for certain on those rare occasions when I have had to pull apart a freshly glued neck joint when after drying I had to refit the joint which now was several miilimeters away from seating due to the permanent swelling of the wood. As David describes I leave just enough of a hollow both across the joint and lengthwise to prove to myself that it isn't dead flat and then glue with fresh strong hide glue clamped at the point where the glue squeezes out in tears but doesn't run all over. Hundreds of instruments no reported failures. Works for me.
  15. I don't size the center joints and as far as I know have never had a failure. I have no compunction about cleating center joints though on the theory that insurance never hurts. I also tend to break the cut offs to check the joint and while I don't usually get a clean break I often don't get as much wood failure as I'd like to see. So David, do you replane the joint after sizing? I would think that would be awfully hard on my precious jointer plane. Likewise What strength glue do you size with?
  16. Roger it is not just recommendation that is required for membership in the Federation. When I joined the requirements were a minimum of three years of apprenticeship as a maker three years of work as a repairman or restorer and three years of managing a business on one's own for a total of nine years of experience Then I had to get three recommendation letters from members and present an instrument to the membership before being voted in by a majority of the members present at the next general meeting.The requirements have changed somewhat over time but a demonstrated competence as a craftsperson is still a prerequisite.
  17. I believe you are wrong. My understanding is that that the authorities were helped in their investigation by several members who became aware of improprieties and contacted law enforcement agencys with their concerns. Since the Federation is a volunteer organization there was no way to take action on the matter until the board could meet and until the facts were clearly understood.
  18. True enough Jacob but the fact that someone is dealing at a high level without any credentials should have raised an alarm with the customers. As Eric Meyer points out there are many well trained and competent V.M.s in North America who are not members of the Federation but there are no members who have not demonstrated a certain level of competence. And as the Beardon case demonstrated we do have at least some control over our members business dealings in that this type of blatant misconduct will result in expulsion.
  19. Try " The renaissance artist at work" I'm at home and the book is at the shop but if you can't find it let me know and I'll post the author's name. Very interesting discussion of the Renaissance view of craftsmanship and art. I believe it's available through Dover Press.
  20. Joe I'm using these brushes and like them but still have problems with breaking and or losing hairs when manipulating thick varnish. Don't know if that is brush technique or if I'm weakening the hair by overly aggressive cleaning. I generally clean with acetone until no more color comes out of the brush followed by soap and water. Any suggestions? For spirit varnishes I use longer haired but similarly shaped sables that I've used for at least twenty years and like very much.
  21. The book as I remember was a basic how to book. I looked for it last night and can't find it so it has been consigned to the back shelf somewhere. I really was surprised to find that he worked for Hornsteiner. I guess writing a beginner level book doesn't mean that's all you know.