They're going sharp, I tell you!

[Dave Nereson]

----- Original Message -----
From: Greg Casper <gcasper@pacbell.net>
To: <pianotech@ptg.org>
Sent: Monday, March 11, 2002 11:27 PM
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
>
    Well, if it's tuned in the winter, when most homes are dry, then when
summer comes along with its rains and higher humidity, the soundboard
absorbs moisture and swells up convexly, pushing the bridge and all the
strings with it, tightening the strings and making them go sharp.
    Also, if you lower the pitch, even if you do a two-pass tuning,
sometimes it tends to creep sharp in the middle a bit.
    Or, it could be in the way you set the pin.  Maybe you're leaving
residual torque in the pins or unequalized tension in one of the string
segments that tends to make the tuning creep sharp.         -- David
Nereson, RPT, Denver