[CAUT] Soundboard finishing material - what and why?

[David Skolnik]

Apologies for double posting to Pianotech & CAUT.  Some subscribers are 
exclusive to one or the other.

Can someones say what they are currently using to seal / finish soundboards 
and what the pros & cons of this, or any other materials might be?  Is the 
expectation that the finish will reduce the seasonal moisture 
exchange?  Does the nature of the particular material or the thickness of 
application affect the board's physical / tonal function?

Thanks

David Skolnik
Too hot to go out