O.K. how about another one!?!

[Ron Giesbrecht]

Hi Greg,

>From what you describe the problem is probably contamination and carefully
examining the center pin you removed should show this.

But did you try rolling the original problem center pin that you replaced on
a flat surface? If there was NO scoring or contamination on the pin, there's
a chance the center pins have started to bend slightly from the accumulative
effects of 20 years of playing (especially if some of this playing was hard
playing).  Rolling a center pin that you have removed on a flat table top
will show this. It's possible that lifting and overcentering the hammer
beyond the string height somehow moves a bent pin (which may also be
slightly loose in the bird's eye) just enough that the center pin now
contacts a different (less worn) part of the bushing and the result is a
very sluggish action center. The same thing would probably happen if the
center pin was scored from contamination.

I've noticed that the higher treble on a piano with this condition may still
be ok when the middle and upper bass section is a problem...I'm not sure of
all the reasons but suspect a pianist can play the middle section of a piano
with more power because a pianist sits in the center of the piano and the
arm action is more downward for the middle keys than when the higher and
lower keys are played. Also its possible that a higher treble string may
break before a center pin would bend on heavy use pianos.

When I've seen the problem happen it's almost always on pianos that are
older, or have received hard use and might also be in a local climate
situation that fluctuates a lot. The amount of hammer and knuckle wear can
give you a clue as to how this piano has been played. After 20 years of use
the G3 is probably ready for a new hammer assembly.

Regards,

Ron Giesbrecht
Piano Service Manager, Yamaha Canada Music
rgiesbrech@yamaha.ca

-----Original Message-----
From: Greg Newell <gnewell@EN.COM>
To: Master Piano Technicians <MPT@talklist.com>; pianotech@ptg.org
<pianotech@ptg.org>
Date: Wednesday, April 14, 1999 11:23 PM
Subject: O.K. how about another one!?!


>Hi again kind folks,
>    I just acquired another strange job. Thanks first to all those who
>are helping me with the heavy Steinway "L" action. I'll get some
>upweight measurements to post as soon as I can get back into my shop for
>a bit. Me thinks I'm learning to juggle!
>    Today I went to tune a 20 yr. old Yamaha G-3 that I just regulated
>about 6 months ago. I encountered quite a surprise. The owner left after
>asking me to look at several notes which he had listed on a pad. I
>looked at the first note in the tenor section (E3) and it had a rather
>tight hammer flange center. O.K. so I repined it and it was nice.
>Proceed down the list. Others were sluggish so I lift a group of hammers
>and release and ... some stayed up!!!! Well , O.K. it's not like I never
>saw that before. I did it again. This time more of them stayed up. I did
>it again. More still!!! O.K. now I'm getting scared! What's going on
>here? When I got here they were just a little slow when the player used
>the sustain pedal taking the extra weight off the back of the key. Now
>..... well it's simply unplayable. The puzzle is that I don't know what
>caused it all of the sudden.
>    I took out my trusty little D-C humidity gauge. Not quite a
>scientific instrument but it give you an idea. I had a reading of 38%
>RH. Well this should be in the good range right? As I check the rest of
>the hammers I notice that none are failing in the bass or high treble
>sections. What gives here? I then started to pull individual hammers
>from all sections and look at the felt center. I noticed a nice bright
>red felt on the two good sections and the other two sections had
>darkened or possibly a contaminated look to them. Now I'm not the first
>tech to work on this piano so I don't know what happened before me. I'm
>not really into the various juices, solvents or the like when I can
>repin or replace and be more sure of the result. I called Yamaha and the
>very kind Mark Wisner suggested that I use the water,soap and (alcohol?)
>solution to size the felt. I've done this before on lesser pianos but
>knowing my customer I figured a more permanent and guarenteeable
>solution is best.
>    My questions to you good people out there are: Have any of you found
>a common problem with the Yamaha grand that would fit this picture? If
>so, what did you do about it?  Mark Wisner thought that perhaps Yamaha
>used a Silicone oil substance years ago for lubrication of centers. I
>assume this was on an as needed basis. Anybody confirm this? If these
>are contaminated would repining be a viable solution? Would replacement
>be better? My customer is convinced (his own thoughts) that replacement
>is better. Are we on track or all wet? Any thoughts why I would see this
>rearing it's ugly head now and I noticed practically nothing only 6
>months ago when I regulated it? It seems such a night and day difference
>between well functioning and impossible repetition. If Yamaha convinces
>my customer that the sizing solution is the way to go, how long can we
>expect it to last?
>    The customer will be calling Yamaha to talk with someone himself. He
>wants to know their mind on the subject. I hope some of you can shed
>some light on this one too. I seem to find some weird pianos to work on
>some times. Thanks again!
>                        Greg Newell
>