Broken Bass string

[Vanderhoofven]

Dear Friends,

Small Full Gospel Pentecostal Church

Energetic Music, including piano, drums, bass guitar, electric guitar,
keyboard and about 6 singers.  Large 18 or 24 track mixer with lots of
preamps, amplifiers and several large  loudspeakers.  Piano has a two part
microphone, on part attaches to the plate, one part attaches to the
soundboard, don't know brand name).

The first small piano -- multiple broken strings -- replaced before I began
tuning there about three or four years ago.

Replacement piano -- 34 year old Everett studio -- no broken strings at
time of acquiring this piano.

In the past three years, I have replaced about 10 or 12 broken bass strings
on this piano, mostly using universal bass strings.

Hammers shaped nicely, about a half day's worth of regulation, softened
hammers considerably, adjusted sustain pedal so as not to lift the dampers
very far.  (Music is usually played only in about 4 or 5 keys, and the
hammers are wearing excessively for the notes corresponding to those keys.
Hammers for the white notes are excessively worn, hammers for sharp and
flat notes are barely worn.)

Yet still strings are breaking.  I have replaced the bass strings on note
D3 about three times.  This spring, I replaced both strings of the unison
D3 with new custom made bass strings from Mapes, from a paper pattern of
the stringing scale.  Today, a phone call from the pastor to replace a
broken string on note D3.

Help!

I know that the archives have information on this, and I have read most of
it.  Is there anything that I can still do that I have not already done?

I shaped the hammers and softened them in hopes that the softer hammers
would help alleviate the problem of broken strings.

I did a fairly good quick regulation of the action, setting let-off at
about 3/16" in hopes that this would help stop broken strings.  

(I did this hammer shaping and regulation on my own time, in hopes that I
could help the church out and learn something for myself as well.  Hey, I
was a beginner, I was learning, I know now how to do the work and don't do
free work anymore, unless the situation truly does warrant it and my wife
and I discuss the situation first.)

I set the damper pedal to lift the dampers a minimal amount, in hopes that
this would help stop broken strings.

What else can I do?  Is this year and model of piano especially prone to
string breakage?  (I tune several other Everett studios and consoles that
do not have this problem).

I don't believe the problem is with the piano, or the replacement strings,
the hammers, or the regulation.  I believe the problem can be isolated to
the pianist, whom I have never seen play.  What possible piano technique
can this pianist be using to enable them to break strings so frequently?
If I go to a worship service there to observe the pianist, what should I
look for?

Thanks for any replies!

David Vanderhoofven
Joplin, Missouri