Extreme jumpiness

[paulrevenkojones at aol.com]

 Tom:

Crack occur internally as well if the block is laminated. Delamination is a form of cracking, and the voids between laminates could easily cause torque differences along the length of the pin, creating more of "twist moment" than a "turn moment". Again, the restringing sounds suspect.

Paul


 


 

-----Original Message-----
From: Tom Sivak <tvaktvak at sbcglobal.net>
To: Pianotech List <pianotech at ptg.org>
Sent: Wed, 17 Oct 2007 9:18 pm
Subject: RE: Extreme jumpiness










It's an open faced pin block.? Looks perfect.? The pins that are loose are generally on the bottom row, though not necessarily adjacent to one another.?? If it's a crack, it doesn't follow a clear path.
  
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Can there be?a crack that can't be seen in an open faced pinblock?? In this case, the wood is beautiful, and not a sign of?a crack.? 
  
?
  
Tom Sivak
  
Chicago

Dean May <deanmay at pianorebuilders.com> wrote:
  
                
  
What kind of piano is this? Are you sure it has a wooden pin block?
  
?
  
  
Dean
  
Dean May???????????? cell 812.239.3359 
  
PianoRebuilders.com?? 812.235.5272 
  
Terre Haute IN? 47802

  
  
  

  
  
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Tom
 Sivak
Sent: Wednesday, October 17, 2007 8:34 PM
To: pianotech
Subject: Extreme jumpiness

  
?
  
  
List

  
  
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Have had the displeasure of tuning an old upright which has been restrung with new oversized pins.? I was called in to tune it by the man who restrung it; he asked me to CA the pinblock because the strings kept
 slipping flat.

  
  
?

  
  
So I went, CA in hand, and found that about 20 pins had fallen, some were a 4th under pitch!

  
  
I got out my tuning lever and pulled the offenders up to pitch and was shocked to find how tight the pins were.? On some of the pins, I literally had to use ALL MY STRENGTH to make the pin move at all.? (And I'm 6 feet tall and 210 pounds.)? Then it would jump a whole step, and I'd try to coax it back, but it would jump back down, too low, and...you know the routine.

  
  
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The reason I'm writing is to gain some insight into this situation, hopefully.? How can a pin be sooo tight that I have to extend my lever, watch it bend as I apply pressure, hoping that my lever won't break, just trying to get the pin to move...and yet not be able to hold?

Now, I've been there three times in the last two months.? The first time, I did not apply any CA to the pinblock.? My God, they were so tight, yet jumpy to the max.? Because it took so much strength to get the pin to move, it was difficult to make any small movements.?? I thought, with my superior tuning lever technique, I would be able to get the pins to hold.? HA!? 

  
  
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Next time I applied CA to all the pins that had slipped.? After it dried, they were tighter than ever, even harder to get them to move.? One month later, about half of them had slipped again.? I re-applied the CA and was there last week.? Only about 6 of them had slipped, but it still boggles my mind.

  
  
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Understand that it is just as difficult to get the pins to go flat.? I mean, as you try and turn the pin, and it jumps to the sharp side on you, and then you try to push it back down, and it jumps to the flat side, and you
 toggle back and forth...it's just as hard to get the pin to move south as it is north.

  
  
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Any thoughts?? Tuning pins too big?? Cracks in pinblock? (Open faced pin block, showing no cracks...)?? Should I use WD-40 instead of CA?? (Just a joke...just a joke...)

Tom Sivak

  
  
Chicago







 


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