Soundboard installation, next topic : the glue

[Ron Nossaman]

> Well I've read so many messages on this list about rib-crowned and 
> supported boards as though it was something new, when I can see nothing 
> different between this and the traditional English method that was 
> practised from about 130 years ago.  I can remember well very early in 
> my career coming across American Steinway grands with the dead singing 
> octaves (what I call the flute section) and this and other really shoddy 
> characteristics of these pianos led me always to avoid them.  I have 
> described the English method, which is outlined in Wolfenden's book and 
> would like someone to explain _precisely_ what you meean with all your 
> CCs and RCs and RCSs.  If Terry Farrell, for example thinks a 15ft 
> radius on the unstrung crown is not exaggerated, I am to take it that 
> his board will be CC, for to be sure it will be compressed if he ever 
> gets it anywhere near flat. There's far too much jargon used here and 
> far too many ideas presented as the very latest thing when they're 
> nothing of the kind. If I with all my experience get confused with all 
> the unnecessary acronyms and fake jargon, goodness knows what the 
> ordinary list subscriber must be making of it.


The acronyms are quite necessary when discussing this stuff, 
to prevent typing the same thing over and over and over, which 
happens in any case.

The definitions as used for the last five years or so on list are:

CC=compression crowned, consisting of flat ribs with panel 
compression forming and supporting crown under both string 
downbearing and the ribs' attempt to naturally straighten back 
out. Steinway US, Steingraeber, and Sauter build boards this way.

RC=rib crowned, consisting of ribs with a crown machined 
directly into them, and supplying positive beam support to 
crown under downbearing in addition to the support supplied by 
panel compression. This is the most common construction method 
among today's manufacturers.

RC&S=rib crowned and supported, consisting of ribs with a 
crown machined directly into them, sized and numbered 
sufficiently to support crown under downbearing load without 
the aid of panel compression. To my knowledge, Walter is the 
only manufacturer building boards this way, though there are a 
number of small shops doing this now, with considerable success.

And no, 15' isn't an excessively tight radius for a machine 
crowned rib. I go down to 4 meter in the treble, Whatever 
Wolfenden has to say about it.
Ron N