They're going sharp, I tell you!

[Stéphane Collin]

Hi Greg.

It is the soundboard that expands when humidity level goes up (any wood
does).  There is some crown in the soundboard shape, made to give a spring
like counter force to the bearing force of the strings.  When the soundboard
expands, the crown in it lifts the bridge up, pulling the strigs sharp.

Stéphane

----- Original Message -----
From: "Greg Casper" <gcasper@pacbell.net>
To: <pianotech@ptg.org>
Sent: Tuesday, March 12, 2002 7:27 AM
Subject: They're going sharp, I tell you!


> Just a general question from a relative newbie... What usually causes a
> piano to sharp between tunings? Going flat is completely understandable,
> from the string streching and/or pin loosening points of view, but what,
> other than maybe temperature or frame flexing, can make a piano go sharp
> over time?
>
> Thanks
>
> Greg Casper
>
>