Making a soundboard-S&S L board

Erwinspiano@aol.com Erwinspiano@aol.com
Wed, 12 Nov 2003 22:15:25 EST


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  List
 In the spirit of "make a soundboard" I continue to observe things that work 
(or not) I currently have a 1960 L in shop for finish stringing & some action 
sprucing. The piano has always lived in a Church sanctuary in Fresno, Ca. 
These people love this piano & were concerned about changing the sound so....
  When a piano sounds really, really good I'm always asking, I wonder why. 
The piano had nicely set bearing & with the strings on as evidenced again with 
the strings off. 
  The amazing thing for me is this sound board has more crown thru out its 
entire rib scale than most S&S I've encountered. I don't work on many this 
young. I stretched a string across the bottom and starting between the top two 
ribs. It had 2 mm of nice hemispherical crown. That equates to approx. 30ft 
radius. Continuing on down & measuring between each rib it had 3.4 , 4 , 5 , 6 , 6, 
5, 4, 3 mm of crown. after doing a mock up pre-stressing check of the bearing 
it had roughly 2 degrees of bearing in the top 2 sections tapering down to 
1&1/2 degrees in the tenor starting in at the treble tenor break The bass was set 
almost to zero. It was really fairly text book S&S bearing set up.
  Also there is only the faintest sign of any compression ridging & that only 
on 1 joint. Modest annular ring spacing (10-12 grains an inch).
  I've rarely measured any crown in the top end of S&S's let alone such tight 
radii for a CC crowned board. I was wondering if it was rib crowned but I 
don't think so. Looks to be about . 330 thick in the middle. It has significant 
crown along the bridge as well, but of course the crown hasn't sunk.
  It's true that it's survived well because of our moderate Ca. climate but 
also something was right when the board was made. This the easiest rebulding I 
do & this kind of thing makes it fun & interesting.
   Dale

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