Soundboard stress cracks

[Pianocraft@aol.com]

David,

I am dismayed that you have apparently been taken in by this obviously sham
explanation of soundboard failure. There must be something in the water up
there in the Vineyard or perhaps you have been losing too much sleep
measuring all those actions, but your usually keen rational faculties have
forsaken you here. Come on, raised grain! Those pesky little ridges will some
day, soon, grow up to become soundboard cracks. I’ve seen it, you’ve seen it
and most every one else has seen it. There is no denying that premature
soundboard failure has been plaguing manufactures and piano rebuilders for
quite some time. The problem has been spotted here in New York, in
Connecticut, in Boston and overseas in the Orient. The only question is why
does it happen?

Here are some clues: when you compress wood more than 1% cell damage will
occur. The soundboard panel is confined by the case, down bearing and , most
of all by the ribs. The moisture content of the soundboard panel during the
ribbing process must be carefully considered in relation to average moisture
content of interior wood work in the area the piano will be living. Other
consideration come into play: hydroscopic properties of adhesives, care in
the panel gluing process and type and thickness of Finish.

For more information contact me privately, I wrote an article for my
blatantly commercial news letter “ Hartman's Fine Piano Rebuilding” on this
subject. It is rather long and I don’t want to clutter the list with it.

John Hartman
pianocraft@aol.com