[CAUT] center pinning changes

[Ted Sambell]

Re: [CAUT] center pinning changesThank you for your response, John. German silver centrepins have long been used in this part of the world.Of course, it is not silver, my understanding is that it is a high quality brass alloy, probably nickel, as you suggest. I think most reputable technicians frown on plated pins. I have both of the tools you show, but on site I use the usual repinning tool because it can be used to press the pins homeas well. To avoid pushing the points through the far bushing I press part way, relax and press a second time, so that the flange straightens itself to line up the holes.I believe most technicians do this. The support block I made is for the same reason as yours; my vision is not good. Once the first flange of a given part is lined up one can remove the rest of the pins of the same set with one's eyes closed, at least theoretically, though I admit I haven't had the nerve to do that yet, but am going to try it with some old parts. I have an Oprivisor to set up very accurately.I am going to videotape this with a blindfold on, and see if it's a disaster.

Ted Sambell
  ----- Original Message ----- 
  From: John Delacour 
  To: College and University Technicians 
  Sent: Monday, September 10, 2007 5:45 PM
  Subject: Re: [CAUT] center pinning changes


  At 20:07 -0400 9/9/07, Ted Sambell wrote:


    ...John, I would be interested in knowing if you have adopted the long wire centrepinning rechniques which seem to have taken over in Europe. Jurgen Goring demonstrated this  in Calgary last year. He is very skilful at it. I understand the Rappaports have given classes  on this too. It is certainly quicker than the separate small pins.


  I mentioned using the wire when doing the hammers of the old Kirkman upright.  For one thing my supplier charges an outrageous price for the very thin pins (eg. 1.20 mm) and less for the wire, and also the wire is advertised to be "Neusilber", ie. German silver = nickel silver, throughout rather than being plated brass, and this seems definitely preferable.  Whether it is in fact homogeneous German silver I have not yet investigated but it looks possible.


  I had a small grinder running on the bench to put a point on the wire as each centre was done and worked just as I would with individual pins.  I charge for recentring 1 minute per centre, though this is an over-estimate for a straightforward job on an untouched piano.  If the "tuner/repairer" has been at it before, then it can be a gross under-estimate.


    For removing the old pins, I have made a support block which goes on the drill press. Once set up it is clamped into place. It accomodates a variety of parts and flanges and provides solid support for the attached parts. This is for repetition work , of course.

  I now always take out the pins with the German tongs:





  I used to use a special small bench press:





  but I have long preferred the tongs since I can hold them where I want, and probably because my eyes are not as good as they were.


     Mounting  a piece of rod in the chuck permits rapid pinning up too.


  I always push the pin in with the nippers (mine are larger than those sold by the suppliers -- 7").  If this is not possible without forcing and without the pin creaking, then for sure the pin is too thick for the hole.  I would never press or hammer the pin in.  Factory work is different from restoration work.  When one is working with new parts of known dimensions and characteristics one can adopt different techniques, but every job in restoration is different.  I now sometimes come across a piano or am called out to see one I re-centred 25 years ago and am happy to say the methods I learned so painfully in the beginning stand the test of time.


  JD



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