center pinning question

[Don Mannino]

Allen,

It's hard to say for sure, but a few more possibilities:

- Pushing the old pin out disturbed the cloth fibers substantially.  This can happen especially when the original pin was cut on both sides, and you have pushed a 'burr' through the bushing in the process of extracting the pin.  The pin extraction tool could also theoretically be rough or bent at the tip, disturbing the cloth a lot when pushing the pin through.

- When installing the new pin, the point of a sharp pin will sometimes snag wool fibers on the through the bushing, causing the fit to become tight.  This doesn't usually happen consistently.

Don Mannino

  ----- Original Message ----- 
  From: Allen Wright 
  To: Pianotech List 
  Sent: Wednesday, May 14, 2008 4:27 PM
  Subject: center pinning question


  In repinning an old (1930's) Steinway M, quite a few were loose. I found that replacing the old pins with the exact same size (but new) pins was producing just the amount of friction needed - and even in some cases adding too much, so that I had to ream with my "Mannino" burnishing files. Any theories on how that happens? Something to do with the nap of the cloth changing in the process, or perhaps the angle of the pin changing in the bushing, or (even more unlikely) that somehow only the outer edges of the pin are slightly worn on the old pins? (These are the various ideas me and my colleagues were coming up with to explain the phenomenon).


  Thanks, and I'll take my answer off the air...   : )



  Respectfully,


  Allen Wright. RPT

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