Soundboard Torture

[Richard Brekne]

I thought the argumentation went along the lines that the soundboard
simply crushes as a result of the compression that resulted from this
kind of crown pressure alone, and that the added pressure from the
string bearing simply exsasperates the problem.

Neat experiment. It shows perhaps more then anything else the importance
of holding instruments within climatic tolerances.

RicB


Farrell wrote:

>  Soundboard panels in pianos exposed to high humidity are trying to do
> what you see above. The stiff ribs and string downbearing pressure
> keep it from actually developing 8 inches of crown. And instead of
> being able to expand and produce this kind of crown, the soundboard
> simply crushes. No wonder soundboard panels develop pressure ridges
> and then cracks when they dry back down! The scale on the left goes
> from about 5.5% MC to about 8.5% MC. The panel should be in the range
> of 18% MC in this photo.
>   Fun stuff! Terry Farrell

--
Richard Brekne
RPT, N.P.T.F.
UiB, Bergen, Norway
mailto:rbrekne@broadpark.no
http://home.broadpark.no/~rbrekne/ricmain.html