buzzing on piano

[David Chadwick]

Thomas,
Check for any glue squeeze around the soundboard edge especially along the 
belly rail. I have solved many buzzing problems by reaching in and breaking 
out the dried glue that dried on the varnished edge on the soundboard where 
the glue oozed from. Where I cant reach with my fingers I will run a 
soundboard tool or screwdriver tip along the joint to loosen any dried glue 
that is not adhered to the panel. The plate bolts should be firmly snug and 
not over. I wonder if anyone has a torque setting for these bolts?

David C

----- Original Message ----- 
From: "Tom & Sharla Zasadny" <zasadny at hotmail.com>
To: <pianotech at ptg.org>
Sent: Saturday, February 03, 2007 9:13 PM
Subject: buzzing on piano


> Greetings,
> What would be the origin of a buzz on this 1930's Steinway Model "M"  that 
> seems
> to be soundboard related and acts like lthis:  It has been present for a 
> couple of
> years; less in the summer and more in the winter and at F5only.  It is 
> more wooden
> than metallilc in quality and is more pronounced with a harder key blow. 
> E5 was
> pitched up to the F5 pitch and caused the same buzz.  F#5 was tuned down 
> to F5
> and also caused the buzz.  Pressure over the bridge, movement of the 
> duplex,
> movement of the strings under the capo, pressure over all ribs and over 
> the
> soundboard top and bottom, tapping the bridge pin down and increasing its 
> angle
> availed nothing. The soundboard has no cracks and bearing is good with 
> good
> sustain.  Visual examination with light and mirror under the plate showed 
> nothing.
> High air pressure through every opening was not productive as well. 
> Muting two
> strings at the F5  quieted the buzz.  When only one was muted, it returned 
> though less
> than with three singing strings.  If I struck two singing strings, the 
> buzz equalled that of
> three strings with a less forceful blow.  Now here is the only diagnostic 
> clue I can
> give.  When the plate bolts were tigtened the buzz disappeared though for 
> only 15
> minutes.  (It came back as I was doing some regulation testing.)  I 
> tightened the bolts
> again and it was quieted for a short time. Tightening again (I put overly 
> heavy torque
> on this last time) lessened the buzz at F5 but it turned up at C6.   Soon 
> the buzz
> became strong at C6 and remained small at F5.  I checked for glue along 
> the entire
> inner rim at the soundboard junction and I eliminated all action and 
> environmental
> sympathetic vibration questions. What is this?  How do I fix it?  The 
> customer is
> piano professor and accomplished performer.  He is ready for this to be 
> history.
>
> Thank you friends,
>
> Thomas N Zasadny
> (home)1(319)-934-3552
>
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