Tuning time -- String Seating

[Joe And Penny Goss]

Hi,
I find that the speed of the false beat also may show its cause.
The slower beats say arround 5 beats per second or less are often due to the
looseness of bridge pins but can be from other causes.
Rust on strings causing unequal string segments of the division of the
octave.
The strings have been lowered in pitch, and now have been pulled into
different location with a kink of the bridge pin in the speaking length of
one of the paired strings. This makes one tunable and the other wild.
Over stretched strings, either from overpulling or the good old roller
routine causing
Thin spots in the string.
The strings that beat like a flutter ( pins cant move that fast <g> ) seldom
seem to be quieted with CA and may be from other causes than the loose pin,
like nonbraided string segments, rust nodes, sympathetic vibration from
other undampened strings or bass strings.
Please add to the list <G>
Joe Goss RPT
Mother Goose Tools
imatunr@srvinet.com
www.mothergoosetools.com
----- Original Message ----- 
From: "Andrew and Rebeca Anderson" <anrebe@sbcglobal.net>
To: <deanmay@pianorebuilders.com>; "Pianotech" <pianotech@ptg.org>
Sent: Saturday, December 17, 2005 7:44 PM
Subject: RE: Tuning time -- String Seating


> It does not hurt to inspect strings at the bridge.  I found a string
> in the treble caught near the top of the bridge pin, how it got there
> is anyone's guess.  I usually do work I call "Piano Voicing" whenever
> I find a piano that requires a significant pitch correction.  I do
> the pitch raise pass a little high.  I check the hitch pin loops and
> tighten them.  I straighten the strings from the hitch pins over the
> rear duplex to the bridge pins.  These are often off in new
> pianos.  I then press forward and down behind and then in front of
> the rear duplex.  Then I take a beat-suppresser bar or a piece of
> brass rod with a groove in the end and push the wire towards the
> bridge and bridge pin pushing down a little.  I then do the same
> thing on the speaking side of the bridge pushing down significantly
> and then towards the pin a little to tighten the curve.  When I do
> this I hear the wire click as tension is passed back behind the
> bridge.  I've done this as annual maintenance on performance
> instruments and had all the wire above the low tenor click
> through.  I suspect that regular tuning methods doesn't keep tension
> up behind the bridge.  On a D that was five cents high after the
> pitch correction pass the pitch fell twenty cents on average after
> doing this.  Leave string lifting/levelling until after you've
> re-tuned or you'll lose it all with the second pitch-correction.
>
> Tuning the rear duplex has been mentioned.  I'm not sure about trying
> to move a whole lot of extra tension there but: keeping it up to
> tension should be done from time to time and would seem to be within
> design parameters.  I've noticed that the rear duplexes do start
> contributing more useful "sounds" after I've done this.
>
> I am against any kind of hammering on the strings at the
> bridge.  I've seen some pretty serious bridge damage on a
> three-year-old D here.  The maple was splintering up on either side
> of the string.  It now has an incorrigible false-beat that is
> definitely at the bridge.  It has one termination at the bridge pin
> and an indeterminate one along some of its length on the bridge.  I'm
> thinking about trying epoxy on it with a hard filler.
>
> If touching the bridge pin with a weight stops the false beating, the
> pin is loose and should be epoxied or CA'd.  If you only dampen it,
> the termination problem is elsewhere.  I found the problem at the
> rear bridge pin or at the capo or agraffe.  Another possibility is
> loose bearing rods or duplexes (more likely to buzz).  One D I'm
> working on has paint and filler right down to the strings on the capo
> (grooved) and I'm going to have to file it back to clean up the sound.
>
> Drifting the wire through the bridge is effective and should not
> damage the terminations at the bridge.  If a wire is up, you will
> push it down.  I have had that happen.  That Estonia with the wire
> caught near the top of the pin does have me
> wondering...?!  Definitely not humidity cycling...
>
> Andrew Anderson
>
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