Crowning methods, was soundboards.

[Ron Nossaman]

>What RH do you glue the ribs to the soundboard at? I assume anything lower 
>than ambient RH would induce some compression crowning (once the piano was 
>exposed to something higher, say, summer's humidity -- today the RH is 
>frightfully low) -- but I freely admit that's just a gut reaction, not a 
>calculation.
>
>Patrick


In the neighborhood of 6%-6.5%. Yes, there will be some compression 
crowning, but not much, and I expect it to be pretty much non-existent in a 
few months under string bearing. Seasonal swings will always change 
compression levels in panels no matter how the soundboard is built. My 
point is that I'm not counting on the panel to support crown either 
initially, or in the long run. The ribs are dimensioned to do that. The 
panel provides stiffness along the grain and rides along with the ribs to 
move air.

Ron N