Tightbond Creep

[Delwin D. Fandrich]

----- Original Message -----
From: "Richard Brekne" <Richard.Brekne@grieg.uib.no>
To: "Pianotech" <pianotech@ptg.org>
Sent: Sunday, April 27, 2003 1:45 PM
Subject: Re: Tightbond Creep


> FWIW
>
> I've seen a fellow in Oslo pull out hide glued soundboards in the course
of a
> demonstration for a convention class. He does this on a regular basis as
he has
> a particular view about how to handle soundboard cracks. He thinks that if
you
> are first going to fix a crack, then you might as well do it as part of a
> larger job of upgrading the panel. So he pops (litterally) out the panel,
pops
> off the ribs, and pushes the panel back together. Reinstallment of the
ribs
> allows him the nicety of being able to machine crown them a bit to add to
panel
> strength. If he does need extra material for the panel, he puts it on one
of
> the edges.
>
> Another fellow I know in Amsterdam also seems to have no trouble removing
> panels glued with hide glue. He's one of these fellows who are fond of
using
> the old panel with new ribs. Works well, lasts a long time.


In both of these cases it should be pointed out that some soundboard
technology has been changed. The end product is no longer a
compression-crowned soundboard assembly. It is now a rib-crowned soundboard
assembly. In terms of sound I can't see how it would matter if the panel
used is the original or new as long as both have structural integrity.

In the case of your friend from Oslo, he is not adding "panel strength" by
machining crown into the ribs, he is only putting in some crown. Unless he
is somewhere adding either height or width to the ribs during all of this he
is actually taking away a bit of strength.

Del