Unstable C5 Grand/ My Introduction

[Benny L. Tucker]

Hi list;
    I am soliciting the advice of you piano tuning wizards to help me solve
a tuning problem.
I have been actively reading all of your posts in digest form, for over a
year now, but have
always been to "shy", to post questions of my own. I am at my wits end on
this particular
piano and need some help. Maybe this will make me more active on the list
huh:-)
    First, since it seems as though I "know" most of you through your posts,
maybe I can
give you some background on myself.
    My name is Benny Tucker, and I live in Thomaston, Ga. "yes that is where
the Yamaha
pianos are made". I work full time at the Yamaha factory as a specialist in
tuning/voicing, on
the vertical piano line. Also, I work in my own business tuning and minor
repair in the evenings
as Precision Piano Tuning and Repair, (I know Terry Peterson uses this name
also), and besides
that I work for a medium sized dealer in Macon, Ga. on Saturdays, and
sometimes in the
evenings after work. Although I feel qualified to tune/service in homes and
Churches, I must
confess that I only started working at Yamaha and learning piano tuning 2
short years ago.
I have always been involved with music for at least the last 32 of my 40
years, though it
has always been guitars, until the last couple of years.
    At the Yamaha plant, I advanced very quickly in learning to tune first
the bass, then the
middle, and high treble, then on to voicing. I am currently learning
Disklavier installation
when time permits. I feel as though I am one of the most qualified tuners
Yamaha has at this
plant, since most tuners only care about getting a paycheck, I have on my
own, learned the
why and how of piano tuning and strive to tune better each day. I am the
only one at the plant
that even cares to learn how to set a temperament aurally, and tune without
a "scope". (we use
the scope to set a single string of all unisons, then tune the unisons
aurally). Outside of the plant
I use RCT, but am trying to learn to set a temperament with just my ears and
a fork.
    Enough about me, now on to the problem:
    Piano is a Yamaha C5 Grand, approximately 13 years old. In a large
Baptist Church that I
am a member of and also play the guitar. There are 2 electric guitars and
electric bass, full drum
set and all amplifiers on stage and right behind the pianist. No humidity
control system on piano.
I got drafted into tuning this piano about a year ago when I felt
comfortable to do so.
The problem is in stability of the unisons, but only in about a 1 or 2
octave area. It starts
about 5-6 notes before the capo bar/plate strut up to about 5-8 notes above
this strut.
Now I'm not talking about perfect unisons starting to whine a little, I'm
talking about unisons
slipping out very badly. I have tried every trick I know, hard blows, medium
blows, and I just
can't get it to stabilize for more than a week. The strings "seem" to be
rendering over the bearing points
good. The tuning pins are tight enough. Believe me folks, I don't know what
else to do, and I
sometimes feel like an incompetent tuner. Every other week or so I go to the
Church and re-tune
unisons, then maybe every couple of months I'll re-tune the whole piano with
RCT.
The pitch stays very stable on this piano, even without a DC system
installed. The piano is
very bright and needs voicing, but the music director likes this bright
sound.
    If this sounds like a hammer technique or string setting problem, please
respond with
advice. I have tuned pianos all over the central Ga. area, and never had a
call back, except
for the recommended 6-month tuning. I feel my techniques are good, but any
and all advice
will be mostly appreciated. FWIW, I did lube the v-bar in this area with
cpl, result=no help.
    Thank you for allowing me to post to this list, and I look forward to
many more conversations
with you all. I'm still a rookie you know....:-)

    Benny L. Tucker