A First Tuning (and tuning / moisture content stability question)

[Ron Nossaman]

> I've seen quite a few pianos that live in abysmal conditions that seem 
> quite stable.  Maybe some of the soundboard specialists out there could 
> enlighten us:  do older spruce panels maintain a more stable moisture 
> content than newer ones?  This question is not intended to ask whether 
> older wood is of better quality than the newer spruce(we all know that 
> everything from the old days is better than anything new.....:-{> )  I'm 
> just wondering about the effects of aging on spruce.  Less flex, but 
> more stability perhaps?
>  
> Dale, Ron O., Ron N.???
>  
> Dave Stahl


I doubt that old wood's ability to absorb and desorb moisture 
is much different than that of new wood. The fact that 
compression crowned boards lose crown and develop cracks would 
seem to indicate that compression damage has some affect on 
the wood's dimensional reaction to moisture changes. For what 
it's worth, doing the math indicates to me that soundboard 
rise and fall is only a minor player in tuning changes with 
humidity swings. The bridge cap moving the strings up and down 
the staggered and slanted bridge pins accounts for a greater 
string path length difference. The bridge cap is subject to 
the same sort of compression damage as the soundboard panel, 
and should also become less reactive to humidity swings as a 
result.
Ron N