Humidity (Moisture mystery)

[John M. Formsma]

We're still in the higher humidity time of year. (It was 52% RH in a couple
places I worked today.)  The system was probably dehumidifying, which caused
the pitch drop.

I always tell people to wait on the tuning after a DC install (or plugging
it in as in your case); I'll come back in 3-4 weeks after the major changes
have happened.

JF

-----Original Message-----
From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Michelle Smith
Sent: Tuesday, October 10, 2006 10:01 PM
To: 'Pianotech List'
Subject: RE: Humidity (Moisture mystery)

Hi Jere and others-

It's interesting that you posted this today.  I tuned a piano for a customer
6 weeks ago and encouraged them to resume use of their Dampp Chaser system
that had been left off for a couple of years.  (We replaced the pads and
filled it with water and the bottled solution.)

They have since kept it hydrated and called to say that the pitch was off
and could I come take a look.  As I assumed would happen, some of the notes
were pretty out of whack but to my real surprise, the whole piano (except
for the high treble) was 14 cents FLAT!  I was quite surprised because I
thought the addition of all that water would cause it to go sharp.

Anyone have any ideas of what happened here?  (I have my own theory but want
to hear from some people with more experience.)

Thanks!

Michelle Smith
Bastrop, Texas