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CA questions

  • 1.  CA questions

    Registered Piano Technician
    Posted 01-15-2020 19:04
    Hi all,
    Yet another CA question:

    The situation: an old Ellington vertical in a cabin way in the woods, marginal condition. The customer complained about a pin that wouldn't hold. On investigation, I found that the coil was right against the plate and had likely ground the hole down with tunings. In fact, about half the strings appeared to have been poorly restrung, with sloppy coils and poor string spacing. The 90-year-old client couldn't remember someone ever installing new strings, but it was pretty obvious.

    Since the pin in question had the coil right up against the plate, I knew that had to be rectified. My plan was to remove the pin, swab the hole with medium viscosity glue, pound the pin in again, and install a new string. So far we've delayed on this fix, and I've muted off the offending string. She might be ok with that, and I'm not sure this piano is worth spending $1 extra on.

    Theoretically though, if we decide to go forward, I'm just wondering what preferences are concerning accelerant (I'd like it dry and firm quickly so I won't have to drive way up in the woods more than necessary).

    The choices: 
    1. swab the hole with CA, spray accelerant in the hole, and pound the pin in.
    2. Swab, spray pin with accelerant, pound in.
    3. Swab, use no accelerant, pound in.

    Sometimes I wonder if accelerant actually changes the characteristics of the glue, such as making it more brittle or something.

    Thoughts?

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    Scott Cole, RPT
    rvpianotuner.com
    Talent, OR
    (541-601-9033
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  • 2.  RE: CA questions

    Posted 01-15-2020 19:39
    It sounds like someone has tapped the pins to press the coils against the plate.
    Clumsy attempts to tap pins can leave irregular coils.
    This is a worn out piano. A new string will need call-backs to stabilize.
    If you put a drop of CA on the coil at the plate, it might hold. You will know in two minutes.
    Consider that for a few hundred dollars your customer could buy a used Kimball or Wurlitzer in better condition.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 3.  RE: CA questions

    Registered Piano Technician
    Posted 01-15-2020 20:09
    Scott,

    I would remove pin, swab, spray catalyst, wait a few minutes, tap pin in halfway and make a judgement as to whether a second application would be better. If so, do it and re-assemble. 

    It is true that the catalyst does affect things slightly adversely, but when time is of the essence it is negligible. 

    If you get it back together and still feel it is too loose, then apply thin CA at the base of the pin. Should do it. 

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 4.  RE: CA questions

    Posted 01-15-2020 21:13
    If you do anything, number 3 with medium thick or thick CA. It'll for sure work.

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    John Formsma, RPT
    New Albany MS
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  • 5.  RE: CA questions

    Registered Piano Technician
    Posted 01-15-2020 23:38
    I would suggest a different approach.

    Remove the coil from the pin, very carefully. (Of course, if it breaks no matter how gentle you are, the string will be replaced and unfortunately you'll make another trip unless you replace it with a hexocore string, hateful things.) Of course, since the string has been rubbing on the plate, and since it has been pulled up multiple times due to the loose pin, it may be fatally compromised already.

    Turn the pin outward about an inch or a little more. Thoroughly wet the pin with CA and turn it back in till it is about far enough out that putting the coil back on and tightening it to pitch will leave the coil at about the right height.

    You could also lay a little bit of thin CA along the place where the pin goes into the pinblock or the plate bushing.

    The CA will set up within a few minutes without any accelerant. Using a hammer on such a fragile pinblock is not a good idea. You could very easily increase the separations and widen the cracks, making more notes in the area untunable.

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    Susan Kline
    Philomath, Oregon
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  • 6.  RE: CA questions

    Registered Piano Technician
    Posted 01-16-2020 10:37
    Thanks for the answer all. Just wanted to clarify that I was most interested in the detail of accelerants.

    --
    Scott Cole, Registered Piano Technician and Doctor of Music
    Serving Southern Oregon and Northern California
    (541)601-9033







  • 7.  RE: CA questions

    Registered Piano Technician
    Posted 01-16-2020 11:06
    Scott,
    If your remedy incorporates removing the tuning pin, why don't you simply put in a larger pin?
    Roger





  • 8.  RE: CA questions

    Registered Piano Technician
    Posted 01-16-2020 15:53
    A larger pin might spread the crack and have a bad effect on neighboring notes. One of the real benefits of CA glue in a failing  pinblock is that it glues things together instead of forcing them further apart.

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    Susan Kline
    Philomath, Oregon
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  • 9.  RE: CA questions

    Posted 01-16-2020 21:38
    Agree completely. And swabbing the hole with medium or thick CA and using the original pin will absolutely work. I've run across many old uprights where the pin(s) was so loose that thin CA dripped in would not suffice.

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    John Formsma, RPT
    New Albany MS
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  • 10.  RE: CA questions

    Posted 01-16-2020 11:16
    CA glues have a rather wide range of behaviors. You need to know your particular CA.
    H2O is an accelerant. Some CA is so sensitive that blowing through a straw will accelerate the glue.
    Very lightly licking the non-glue (!) side of a joint may help set  the CA.
    I have settled down to one thin CA and one medium CA, and am familiar with their working qualities.

    In the case you describe, I consider that first I am there to serve the customer, and that provides the context in which I service the piano.
    In such situations I usually seek to avoid avalanches.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 11.  RE: CA questions

    Posted 01-16-2020 11:20
    If there's no time of the essence factory involved why the need for accelerants?

    In doing something with CA the other day one of my sons who was working with me asked me why I wanted to use an accelerant and told me merely to breathe on it, being moisture sensitive. Of course he was right.

    In another field, I modify loudspeaker units and use CA for my modifications. In that circumstance there's a need to use the accelerant so as to get the glue to set before it leaks out and goes into the magnet gap down the side of the voice coil. In no tuning plank related circumstance can I imagine a similar requirement to stop it in its tracks before it gets to somewhere it shouldn't . . . 

    Best wishes

    David P

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    David Pinnegar, B.Sc., A.R.C.S.
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    +44 1342 850594





  • 12.  RE: CA questions

    Registered Piano Technician
    Posted 01-16-2020 15:50
    I never liked the way accelerants smelled, and I've found them unnecessary. Why would one need for a glue to set up in a quarter second when it usually sets up in five or ten seconds, if spread thin enough? And moisture (humidity, breathe on it) is a decent mild accelerant.

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    Susan Kline
    Philomath, Oregon
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  • 13.  RE: CA questions

    Member
    Posted 01-16-2020 22:34
    Why not skip using CA altogether and carefully get the string coil off the pin . Back out the pin and make a sandpaper shim so the pin threads will bite into the sandpaper backing and the grit rubs the tuning pin walls. If it is done properly the shim should keep the string and coil at the proper height and allow it to be tuned to the proper pitch. Be careful using CA and accelerant around older customers who may have breathing issues and who may be sensitive to chemicals. If CA is used for treating an entire pin block the fumes can be quite strong. Granted if you going to use it on one pin it is not a lot of fume but people have different threshhold levels.

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    843-325-4357
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  • 14.  RE: CA questions

    Registered Piano Technician
    Posted 01-17-2020 02:58
    That's why I use a minimal amount of CA on only the pins which really need it, and I never use the accellerant.

    Treating a whole pinblock I consider malpractice with a toxic substance -- though to each his own.

    A sandpaper shim would work, but it wouldn't have the virtue of thin CA, which loves to follow cracks.When several loose tuning pins in the same area are treated, the CA wicks in, meets itself deep in the pinblock, and sticks everything back together.

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    Susan Kline
    Philomath, Oregon
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