Board stiffness, was Hammer Types

[David Love]

I don't know that there is an easy, elegant way other than listen.  Before
destringing the piano is a good time to listen and assess with samples.  You
can then make decisions to try and stiffen the board with, say, an epoxy
treatment, leave well enough alone or put in a new soundboard.  Depending on
the piano and how much of a disaster the original scaling is, I don't like
to alter scale tensions too far from the original with the exception of
smoothing out bumps and transitions.  If you are putting in a compression
style board I think it is good to test.  If it's a RC&S board in which the
loads are precalculated, you will have a better chance at predicting the
outcome.  Experience is the best guide, and try and approach each
restringing/hammer selection job without preconceived notions.  

David Love
davidlovepianos at comcast.net 
www.davidlovepianos.com

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Jason Kanter
Sent: Friday, October 06, 2006 9:38 AM
To: Pianotech List
Subject: Board stiffness, was Hammer Types

As I'm hip deep in scaling spreadsheets, my curiosity is aroused... What's 
an easy [elegant] way to assess how stiff a soundboard is? Perhaps when one 
evaluates a restringing, one wants to match the scale tension to the board.

Thanks
Jason

----- Original Message ----- 
From: "David Love" <davidlovepianos at comcast.net>
To: "'Pianotech List'" <pianotech at ptg.org>
Sent: Friday, October 06, 2006 7:00 AM
Subject: RE: Hammer Types


<snip>
> I think you can draw the conclusion that generally speaking the lower the
> tension and lighter (or less stiff) the board the softer the hammer that 
> is
> required.  One problem is that not all scales match the boards they are 
> on.
> You see low tension scales on a relatively stiff boards, high tension 
> scales
> on loose boards and all kinds of combinations both by design and because 
> of
> changes in the s/b assembly over time. ...
> David Love
> davidlovepianos at comcast.net
> www.davidlovepianos.com