tuning pins and changes in humidity

[Delwin D Fandrich]

----- Original Message -----
From: "Don" <pianotuna@accesscomm.ca>
To: <pianotech@ptg.org>
Sent: September 06, 2002 8:09 AM
Subject: tuning pins and changes in humidity


>
> Any other theorys of how this happens out there?
>
> At 07:23 AM 9/6/02 -0400, you wrote:
> >"Holes in wood get smaller as humidity goes down..."
> >
> >I have heard this before. Believe me, I am not trying to start an
> arguement - just trying to understand. If a hole gets smaller, then why do
> tuning pins get more loose with lower humidity?
> >
> >Terry Farrell


You might consider the coefficient of friction between wood cells and steel
at various wood moisture content levels.

I can't see the hole dimensions within a multi-laminate pinblock changing
much with changes in humidity and/or moisture content. That being the case
about the only thing left is the coefficient of friction at the interface
between the two materials, the variable being the amount of moisture in the
wood cells.

Del