[pianotech] Sticking key question

[Tom Servinsky]

Matthew,
To add to Dean's thoughts, there is a well documented problem where the dye of the felt actually caused the spoon metal to corrode excessively. The result causes the plating of the spoon to be completely corroded away making the spoon very much like a sandpaper paddle cutting away at the felt. Thus a large gouge would occur in the felt causing the spoon to get caught in the formed grove.
I've seen some advanced situations where the felt was complete scraped off of the underlever, leaving a massive gouge. If this is the problem, it would be wise to consider replacing all damper  underfelts and then thoroughly cleaning the spoons. Otherwise this problem will occur again and again.
The quick and dirty way of correcting the immediate problem is to remove felt from the damper lever and flip it over and turn it upside down so that you have a new fresh service to deal with. re-glue and you are back in business. You'll have to take something like steel wool or 400 sandpaper to clean the spoon surface to a smooth finish. Again, remember to not to only to deal with the felt, but also the spoon surface.
The root of the problem is that the felt is supposed to be washed thoroughly after the dying process in order to remove any extra chemicals which might act as a corroding agent down the road. 
Tom Servinsky
  ----- Original Message ----- 
  From: Claude Harding 
  To: toddpianoworks at att.net ; pianotech at ptg.org 
  Sent: Wednesday, February 18, 2009 8:04 PM
  Subject: Re: [pianotech] Sticking key question


  Matthew,
    I think Dean May has identified the problem.  

  If using the pedal to disengage the dampers from the equation causes the keys to come back up, that is characteristic of a damper spoon hanging up in the damper lever felt.  Sometimes the damper spoon gets dirty or corroded, or poorly adjusted, and digs a divot in the felt on the damper lever, then hangs up in it.

  Engaged dampers would help to overcome most other causes of sluggishness in the action.

  The problem may be apparent with only the three keys now, but other notes may be worn and ready to cause problems in the near future.  Be sure to check them all.  You will have to pull the action to get a good look at everything.

  Good luck!
  Claude Harding



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  From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Matthew Todd
  Sent: Wednesday, February 18, 2009 5:07 PM
  To: pianotech at ptg.org
  Subject: [pianotech] Sticking key question


        I had a client call me today with several sticking keys.  I understand that diagnosing a sticking key problem over e-mail is next to impossible, but my client gave me some info that I thought possibly some of you, with experiences, might give me a few ideas as to the source of the problem.

        The piano is a Kimball console.  My client says that when she plays the piano while using the damper pedal, nothing is wrong.  But when the piano is played without the pedal, at least three keys stay down, and then slowly come up.  In fact, she said that when the keys are down, she'll press the damper pedal, and they will return on their own.

        That is the situation, and if anyone has ideas, I will listen.

        Thank you in advance,


        TODD PIANO WORKS 
        Matthew Todd, Piano Technician 
        (979) 248-9578
        http://www.toddpianoworks.com 
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