Soundboard Crack

[Warren Fisher]

Lkunsky257@aol.com wrote:
>
> In a message dated 97-04-05 02:09:37 EST, you write:
>
> <<
>  Date: Fri, 04 Apr 1997 22:10:12 -0500 (EST)
>  From: PNOTNR@aol.com
>  To: pianotech@byu.edu
>  Subject: Re: Soundboard Crack
>  Message-ID: <970404221011_1320180710@emout04.mail.aol.com>
>
>  In a message dated 97-04-04 18:24:39 EST, you write:
>
>  >On closer examination, I found a 3 foot crack in the
>  >>soundboard running along the top of the bridge.  I can see daylight
> through
>  >>this baby! How do I fix this and keep the bridge/soundboard relationship
>  >>strong??  Epoxy?  Is it possible?
>  >
>  >Laura:
>  >
>  >Please explain how the soundboard can run on top of a bridge. The
> soundboard
>  >is under the bridge.
>  >
>  >Wim
>  >
>  >
>
>  I suspect that Laura means the crack is in the portion of the soundboard
>  vertically above the bridge.  (We are talking about a vertical piano,
> right?)
>   Are you finding that this crack allows the board on the bridge side of the
>  crack to be pressed down lower then the other side?
>
>  I think you'd need to repair any board/rib separation (Tightbond ought  to
> be
>  fine), and then encourage the use of climate control.  I assume that you're
>  not considering tearing down the piano and shimming the board.  If all of
>  your glue joints are solid,  I think the crack itself is more of a cosmetic
>  concern.
>
>  I second David's suggestion that you contact Don Mannino.   (Esp. on a newer
>  instrument)
>
>  Gordon Large, RPT
>   >>
>
> Thank you, Gordon .  Your suspicions are correct about the location of this
> crack.  What concerns me most is the death of the tone due to the bridge
> separating from the soundboard.  I'm assuming that the tone will improve once
> the epoxy closes the gap.
>
> I intend to lower the tension on all the strings, move the strings that are
> in the way, and fill the crack in the board and under the the bridge with a
> wood colored epoxy.

Laura,

Repairing loose ribs is best done with Tite-bond rather that epoxy.
Epoxy is good more for gap-filling like the crack, but the loss of tone
indicates interuption of sound travel in the board and that usually
means the board is loose from the rib somewhere.   Go on the back side
and press the edges of the crack where it goes under the ribs and see if
the board moves away from the rib.  Sometimes you can insert a business
card under the rib by the crack.  Titebond, if it is clamped properly,
will make a "vacuum bond" between the rib and sound board which will be
stronger than the wood surrounding it.  Of course, clamping a soundboard
s another subject with a lot of squirrels running around!  Let me know
if you're not familiar with the process.

Good Luck

Warren

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Warren D. Fisher
fish@communique.net
Registered Piano Technician
Piano Technicians Guild
New Orleans Chapter 701