[pianotech] Inverted soundboard

Don Hubbs donhubbs at mwt.net
Tue Dec 7 08:05:27 MST 2010


I have only seen one other inverted board, on a brand new Baldwin console of
the same vintage. It went back to the factory. This piano was in a black
Pentecostal church and had several broken bass wires when I acquired it,
along with some broken off catcher wires in the bass end. It looks like a
pinky ring or really strong fingernail has whittled away at the cheek below
low A.  The sustain pedal was even bent. Could it really just have been
played hard enough to cause the inversion? It has been damp. There was a
fine mold residue on the keys and inner case surfaces.

 

Don Hubbs

 

  _____  

From: Delwin D Fandrich [mailto:del at fandrichpiano.com] 
Sent: Monday, December 06, 2010 11:47 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Inverted soundboard

 

Personally I'd be a little curious about just how all that reverse crown got
in there. If the factory boys set the strings anywhere remotely close to the
right place on those vertical hitches there shouldn't have been enough
string bearing to force the board that far back. Flat, maybe, but not all
the way back so the ribs are resting on the backposts. Makes me wonder just
how there ended up being enough force against the bridges to cause this to
happen in-what?-just 20 years. 

 

The fairly substantial ribs in these things should have been crowned to
something like a 72' foot radius-don't ask-and I don't care how wet or dry
the piano might have gotten in those 20 years I don't see how climate alone
could have created all this damage. If the piano was in a very humid climate
the soundboard should have done what soundboards do; developed a bunch of
compression ridges and crushed. If it got all dry the panel should have just
split wide open. Seems to me that to force that kind of inversion into the
system there would have to have been a whole lot of excessive string bearing
pressing against the bridges. Where did it come from? And is it still there?

 

ddf

 

Delwin D Fandrich

Piano Design & Fabrication

620 South Tower Avenue

Centralia, Washington 98531 USA

del at fandrichpiano.com

ddfandrich at gmail.com
Phone  360.736.7563

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Dale Erwin
Sent: Monday, December 06, 2010 8:53 PM
To: pianotech at ptg.org
Subject: Re: [pianotech] Inverted soundboard

 

Bummer Don
  As a last resort.  See if you can create a space between the post and the
soundboard so there is no impingement.  Who knows it may sound quite good.
Perhaps you are unaware that some makers Have & are producing reverse crown
boards and they sound quite good.  At this point you and the client have
nothing to loose.
  Good Luck

 

 

Dale S. Erwin
 <http://www.Erwinspiano.com> www.Erwinspiano.com
Custom restoration
Ronsen Piano hammers
Join the Weickert felt Revolution
209-577-8397
209-985-0990

 

 

-----Original Message-----
From: Don Hubbs <donhubbs at mwt.net>
To: pianotech at ptg.org
Sent: Mon, Dec 6, 2010 7:02 pm
Subject: [pianotech] Inverted soundboard

I have a 1990 Baldwin 6000 (52" upright) with an inverted soundboard. The
piano was evidently in a very damp environment at one time, since there were
several loose glue joints, including the bass bridge to apron and some
plywood delaminating in the bottom board . The inversion is severe enough
that the ribs near the center of the board are pushing against a back post.
The tone is even but weak. Is there any way to flip the soundboard back to
its original position without destroying it? Can I just remove some wood
from the back post to give the rib clearance and expect that to enlarge the
tone? Bearing can be adjusted because of the Accu-hitch pins. Thanks for any
suggestions or prior experiences.

 

Don Hubbs

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