Restoring crown in old soundboards

[Ron Nossaman]

>While the list is discussing soundboard crown at the moment, I thought I
>might mention that a piano dealer sent a 100 year old Steinway grand with a
>badly cracked soundboard back to the factory in Hamburg for restoration.
>Well, £8000 ($12k) and 3 months later it came back sounding perfect. To my
>surprise, I was told that, the factory did not install a new soundboard but
>instead repaired the original by shimming, i.e. filing in the cracks with
>those V shaped wedge fillets.
>  When I was at piano college we were told that this is a method used to
>restore crown "in situ" as it were. The theory, I suppose, is that if you
>wedge more material into the panels, it will force the panels to bow or bend
>back into shape. I have not yet had the opportunity to put this to the test,
>but have any of you tried this method or think it feasible.
>
>Regards
>Alan Forsyth


I expect all of us have been taught or told this. Most of us who rebuild 
have tried it. Some of us who have tried it have learned that it doesn't 
work. When the crown of a compression crowned soundboard is gone, it's 
because the cumulative compression set in the panel will no longer allow 
the panel to support crown. Putting a couple of centimeters of shim width 
in a meter wide (or more) panel of crushed wood won't resurrect it. Any 
"restored" crown will be very short lived. It's not a fix, only a cosmetic 
disguise.

Ron N