Pianotech

Servicing a college with an RX-6 Kawai grand.  It has a half dozen loose/jumping pins.  All together, in the same row of pins.  I'm suspicious of a crack, or a separation in the lamination of the block.   They're still holding, but I really want to avoid having to deal with them the day of a concert.  This particular piano (on the stage in the auditorium) is proving impossible to control climate, with 30% swings in humidity and 10-degree temperature swings.  Additionally, they seem to be unable to keep the Piano Lifesaver System plugged in and filled. 

So --- is CA glue the way to go here?  I've used it to tighten pins, but can I assume that it will also deal with the "jumping"?   Is it worth a try before pulling pins and resizing?  (Which I'm unsure of, given the possibility of a crack.) 

Thanks, as always!

--- Tim

------------------------------
Timothy Edwards
Beckley WV
(740) 517-7636
------------------------------

Much as Wim suggested, contact David Reed at Kawai tech support. He'll supply a few pins of the appropriate diameter (somewhere between 1/0 and 2/0 as I recall), and pay for your work if the piano is within the warranty period (and sometimes beyond). 

------------------------------
Patrick Draine RPT
Billerica MA
(978) 663-9690
------------------------------

I too have had this problem, once in a home and once in an institutional setting (extreme humidity swings and unwillingness to do anything about it). 

I found that in removing the pins so as to install oversize ones (supplied by Kawai but poor quality...very poor) that they actually tightened up significantly upon reversal, often pulling the plate bushing out with it. It was a nightmare job for which I ended up oversizing the worst ones and CAing the remainder. (The institution I basically told to go find someone else as I did not want to deal with it since they were not interested in properly caring for it).

Peter Grey Piano Doctor 

------------------------------
Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
------------------------------

Original Message:
Sent: 02-25-2023 14:41
From: Edward Foote
Subject: Loose/jumping pins

Greetings,

  I also ran into an RX that had three loose, jumpy pins in a row.  As per Kawai's tech advice, I installed the oversized pins they sent me.  Now I have tight, jumpy pins.  I think it would have been better to have first applied some CA to these three pins, as I haven't run into jumpy pins with CA, but oversized pins have often resulted in them.  

Regards, 

I would suggest that the loose pins be removed, the hole lightly be cleaned with a soft wire brush (gun cleaning brush?), and 7.0mm x 60mm pins be installed. Kawai often sends 7.0 x 64 (1/0) or even 7.15 x 64 (2/0), and these will be too tight!  The factory pins are 6.9mm x 64mm

The wire brush will clean the inside of the holes, and that will help with the jumpiness tremendously.

When the pins become tighter as you spin them out, it is because the bushing is rotating with the pin.  This is VERY common if someone has attempted to tighten the pins with C/A glue - it is super difficult to get the glue to go past the pins and into the block, unless the piano is flipped upside and they are treated from below.

When you turn out the pins, it also helps a lot to remove them slowly with a power drill and be careful not to wobble the drill. If you do it manually, then turn the lever only in a 90º arc, lifting the lever off and moving it back.  So, start at 2 o'clock and rotate to 10 o'clock, lift off and put it back to 2 o'clock.  It is slow, but it usually keeps the bushings in place because then the tuning pin is not being wobbled around in the hole.  That is what causes the bushings to come up - if they haven't been glued to the pin.

------------------------------
Don Mannino RPT
------------------------------

Cleaning the holes with gun barrel brush is, I think, a very good prophylactic measure against jumpiness. Just be sure not to get too aggressive with it as it removes wood (and we know where that leads). 😉  DAMHIK!

Peter Grey Piano Doctor 

------------------------------
Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
------------------------------

Original Message:
Sent: 02-25-2023 21:53
From: Don Mannino
Subject: Loose/jumping pins

I would suggest that the loose pins be removed, the hole lightly be cleaned with a soft wire brush (gun cleaning brush?), and 7.0mm x 60mm pins be installed. Kawai often sends 7.0 x 64 (1/0) or even 7.15 x 64 (2/0), and these will be too tight!  The factory pins are 6.9mm x 64mm

The wire brush will clean the inside of the holes, and that will help with the jumpiness tremendously.

When the pins become tighter as you spin them out, it is because the bushing is rotating with the pin.  This is VERY common if someone has attempted to tighten the pins with C/A glue - it is super difficult to get the glue to go past the pins and into the block, unless the piano is flipped upside and they are treated from below.

When you turn out the pins, it also helps a lot to remove them slowly with a power drill and be careful not to wobble the drill. If you do it manually, then turn the lever only in a 90º arc, lifting the lever off and moving it back.  So, start at 2 o'clock and rotate to 10 o'clock, lift off and put it back to 2 o'clock.  It is slow, but it usually keeps the bushings in place because then the tuning pin is not being wobbled around in the hole.  That is what causes the bushings to come up - if they haven't been glued to the pin.

------------------------------
Don Mannino RPT
------------------------------

Given the school's budgetary concerns (this piano is long off warranty), can oversized pins be used AFTER using CA glue or does this cause "issues"?   I'm guessing they'll likely want to proceed with the least costly alternative. 

------------------------------
Timothy Edwards
Beckley WV
(740) 517-7636
------------------------------

Original Message:
Sent: 02-27-2023 08:23
From: Peter Grey
Subject: Loose/jumping pins

Cleaning the holes with gun barrel brush is, I think, a very good prophylactic measure against jumpiness. Just be sure not to get too aggressive with it as it removes wood (and we know where that leads). 😉  DAMHIK!

Peter Grey Piano Doctor 

------------------------------
Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
------------------------------


Original Message:
Sent: 02-25-2023 21:53
From: Don Mannino
Subject: Loose/jumping pins

I would suggest that the loose pins be removed, the hole lightly be cleaned with a soft wire brush (gun cleaning brush?), and 7.0mm x 60mm pins be installed. Kawai often sends 7.0 x 64 (1/0) or even 7.15 x 64 (2/0), and these will be too tight!  The factory pins are 6.9mm x 64mm

The wire brush will clean the inside of the holes, and that will help with the jumpiness tremendously.

When the pins become tighter as you spin them out, it is because the bushing is rotating with the pin.  This is VERY common if someone has attempted to tighten the pins with C/A glue - it is super difficult to get the glue to go past the pins and into the block, unless the piano is flipped upside and they are treated from below.

When you turn out the pins, it also helps a lot to remove them slowly with a power drill and be careful not to wobble the drill. If you do it manually, then turn the lever only in a 90º arc, lifting the lever off and moving it back.  So, start at 2 o'clock and rotate to 10 o'clock, lift off and put it back to 2 o'clock.  It is slow, but it usually keeps the bushings in place because then the tuning pin is not being wobbled around in the hole.  That is what causes the bushings to come up - if they haven't been glued to the pin.

------------------------------
Don Mannino RPT

A little rosin mixed with alcohol so that it is about the viscosity of fish glue and swabbed around the hole might do the trick. 

First, remove the pin as Don Manino describes, swab the hole entirely with the rosin and re-insert the pin, again very carefully. 

If the pin is too loose, increase a half size. The rosin will remain in the hole and the jumping will be resolved. 

If it's more than 3 pins in the same row, there may be an internal failure in the plank. In this case, a more aggressive approach would

be needed. I have had good luck coating the hole with paraloid and thin viscosity epoxy. Then use the brush as Don indicates to 

size the hole and use a brand new pin. 

Hope this helps. 

------------------------------
Dave Conte, RPT

Resident Technician
The University of Tennessee
Knoxville TN
(817) 307-5656
Owner: Rocky Top Piano
------------------------------

Dave,

Are you mixing the paraloid (presumably B-72) with the epoxy? This is not clear from your post.

Peter Grey Piano Doctor 

------------------------------
Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
------------------------------

Original Message:
Sent: 02-28-2023 07:46
From: Dave Conte
Subject: Loose/jumping pins

A little rosin mixed with alcohol so that it is about the viscosity of fish glue and swabbed around the hole might do the trick. 

First, remove the pin as Don Manino describes, swab the hole entirely with the rosin and re-insert the pin, again very carefully. 

If the pin is too loose, increase a half size. The rosin will remain in the hole and the jumping will be resolved. 

If it's more than 3 pins in the same row, there may be an internal failure in the plank. In this case, a more aggressive approach would

be needed. I have had good luck coating the hole with paraloid and thin viscosity epoxy. Then use the brush as Don indicates to 

size the hole and use a brand new pin. 

Hope this helps. 

------------------------------
Dave Conte, RPT

Resident Technician
The University of Tennessee
Knoxville TN
(817) 307-5656
Owner: Rocky Top Piano
------------------------------