[CAUT] strange rib damage

[David Love]

It is at right angles.  The grain on the rib runs along the length of the
rib and the soundboard grain runs about 90 degrees to that.  I can't imagine
that even stepping on the soundboard in that spot (much less lying on it)
while cutting the notches would stress the rib enough to crack it given the
proximity to the belly rail and the fact that the panel shows no sign of
excessive deflection.  I would guess that the rib was cracked when it was
installed (perhaps dropped in the factory?) and the crack opened up over
time with some downbearing load and humidity swings.  

David Love
www.davidlovepianos.com


-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of
prescottpiano at juno.com
Sent: Wednesday, December 08, 2010 11:35 AM
To: caut at ptg.org
Subject: Re: [CAUT] strange rib damage

I may be confused, but is the grain orientation of the rib wrong in Kent's
picture?  I would think the grain should be at a right angle to the
soundboard.
Larry Messerly

---------- Original Message ----------
From: Jim Busby <jim_busby at byu.edu>
To: "caut at ptg.org" <caut at ptg.org>
Subject: Re: [CAUT] strange rib damage
Date: Wed, 8 Dec 2010 10:32:33 -0700

Hi Conrad,

I ditto that experience. An upright. Clearly a footprint on the other side.
I'm sure a small crack, too much pressure of some kind, etc. could have been
the issue in another piano, but that looks just like what we had in not one,
but two places. 

Jim
________________________________________
From: caut-bounces at ptg.org [caut-bounces at ptg.org] On Behalf Of Conrad
Hoffsommer [choffsommer at hotmail.com]
Sent: Wednesday, December 08, 2010 5:25 AM
To: caut
Subject: Re: [CAUT] strange rib damage

The only time I've seen something similar, there was a footprint on the
soundboard... ;-{
(not mine)

Conrad Hoffsommer




________________________________
From: PAULREVENKOJONES at aol.com
Date: Wed, 8 Dec 2010 00:25:22 -0500
To: caut at ptg.org
Subject: Re: [CAUT] strange rib damage

Two instances of the same very rare phenomenon? An undetected crack when
built? Seems unlikely to me.

Perhaps a misplaced clamp during construction? As well as asking a lot of
sugar pine? Seems more likely to me.

Mysteries. God I love this profession.

Paul

In a message dated 12/7/2010 7:12:06 P.M. Central Standard Time,
rnossaman at cox.net writes:
I've seen it, usually accompanied by 3&#65533; treble bearing. I figured it
was
an undetected crack when the board was built, compounded by asking a lot
structurally of sugar pine ribs.

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