Soundboard question

[Farrell]

I really don't know for sure, but my guess is that the compression set 
damage would occur locally - most likely in linear bands of lower wood 
strength (resistance to crushing). So you'd end up with 90% of the panel 
more-or-less undamaged and 10% of it severely damaged and prone to cracking 
very easy, etc. It might be a bit more stable with fluctuating RH I suppose, 
but I suspect you'd be a lot better off by simply starting with a laminated 
panel to begin with.

Terry Farrell

----- Original Message ----- 
From: "Richard Brekne" <ricb at pianostemmer.no>
To: <pianotech at ptg.org>
Sent: Monday, August 18, 2008 11:43 AM
Subject: Soundboard question


>    How would you "pre-compress" a panel at all and how would you
>    control or even know what a 25% compression is?
>
>    David Love
>
>
> You could pre-compress by simply restricting expansion in all directions 
> whilst letting the panel / flitchs take on humidity. By 25 % compression 
> set I mean subjecting the thing to enough stress so as to force it into 
> compression set so the panel looses 25 % of its original change in 
> dimension.  If it lost  1 mm due to drying it would regain only 0.75 mm 
> after the process at the original MC.
>
> Its not so much how to go about it I am asking about... as much as 
> thoughts on the presumed  benefits of doing so.
>
> Cheers
> RicB
>