Buzz problem

[Delwin D Fandrich]

Bill,

I'm going to guess that this piano has a laminated soundboard. The symptoms
you describe are those I have encountered on several different (always
low-end) pianos with soundboard veneers that are coming apart.

If this is the problem you may be able to fix it by determining the area
affected--I could tell by tapping and listening--and injecting glue through
the very small holes you drill just for the purpose.

If this does turn out to be the problem and you need more information about
the fix, let me know.

Regards,

Del


----- Original Message -----
From: <Maxpiano@AOL.COM>
To: <pianotech@ptg.org>
Sent: June 27, 2001 8:15 PM
Subject: Buzz problem


> I ran into a problem today that I could not correct despite an hour of
trying
> before tuning the piano.  I was stymied despite my nearly 50 years'
> experience tuning pianos.  Has anyone on the list experienced the same and
> found the answer?
>
> The piano:  a Baldwin Howard spinet, S/N 1,095,157 (1976).  A rattling
buzz
> with hollow, false tone in the first octave or so of the bass indicated a
> loose bass bridge.  Not so.  Bridge was tight to the shelf, the shelf
tight
> to the sound board.  Yet pressure against the bridge would restore the
tone
> just as with a loose bridge.  Seating strings made no change.
>
> Pulled the piano out from the wall.  No junk lying there, no loose ribs,
no
> separation of the sound board from the liner.  I scraped the sound
> board-to-liner joint for loose glue.  I got a bit but there was no change
in
> the tone.  I checked the sound board button screws, all except one were
> tight.  Anchored that one and still no change.
>
> I noted one curious fact:  from the front, I could stop the buzz by
pressing
> elsewhere, such as on the tenor bridge above the "loose" area and on the
> board in the same area.  Checked the area between plate and board with a
> flexible steel, but found nothing.  Checked with a mirror to see if the
plate
> was coming loose bottom, but its "nubs" were right up against the board.
>
> From the back, with the customer banging low C, I was able again to
silence
> the buzz by pressing in the general area of the bass bridge.  Then I
became
> aware that there was a scraping, grating sound as I pressed in on the
board,
> and again as I released it.  (I recall a similar experience with a new
> Baldwin grand in the early '70's; I never did hear how the dealer handled
> it.)  There is a hole in the sound board (plate bolt) in this area, but
there
> is plenty of clearance with the bolt.
>
> The board gives the impression of solid spruce, but the joints visible in
the
> front do not correspond with the joints visible from the rear. Am I
dealing
> with a laminated board and could it be delaminating?  If so, what can be
done
> about it?  The cutouts around plate bolts show no separation, yet the area
> around the plate bolt between bass and tenor bridges is the area where
> pressure silences the buzz.
>
> Since I am on a trip, the customer is over 100 miles from my home and I
will
> be passing by their home on my way back in two days (Friday), I would
> appreciate any input from the group.
>
> Bill Maxim, RPT
> Columbia, SC
>
>