[CAUT] curious...

[Gerald Groot]

Hi Ron,

We both basically have the same type of weather.  With Calvin College,
generally in August, the RH is 65% +.  September it's in the lower 60% to
mid 55% RH range.  By November it's usually at least around 30's % RH and by
the first of Dec it's usually around 25% RH or less.  By the end of
December, it is often in the 18 % RH range here.  

During this whole process of weather changes and RH changes, especially this
year, going from August through December, the piano is drying continually,
little by little consequently also going flatter, little by little.  My RH
went up this month too in some of the rooms to as much as 35 %.  While in
other rooms, it was only at 17 or 18% RH.  All of the pianos regardless were
still flat.  Some flatter than others but, nonetheless, they were still all
flat.  

I believe because of the constant drying since August and probability that
your December was likely similar to mine with a lower RH toward the end of
the month, that the piano will not go up in a short amount of time but
instead will continue to go flatter because of a shrinking sound board (and
other reasons) since September or so.  It's been drying out for months
already whereas, the RH has only gone up briefly.  It will go back down
again as the temp outside also goes down and the heat in our buildings
continues to stay on for longer periods of time.  

At least, that's my theory!   

Jer

-----Original Message-----
From: caut-bounces at ptg.org [mailto:caut-bounces at ptg.org] On Behalf Of Ron
Koval
Sent: Saturday, January 29, 2011 12:44 PM
To: caut at ptg.org
Subject: [CAUT] curious...


I've noticed something curious over the last couple of weeks on many of 
my institutional tunings.  The pianos are starting out a little flatter
than would normally be expected considering the snapshot of RH that I
record.

Here's an example from a Yam p22 in the college choir room

Tuned early sept 60%RH
late sept 49%RH - ave 5cents low
early dec 29%RH - ave 20 cents low

all of the above reflects what I normally see.

today 31% RH - ave 10 cents low...

I guess a data-logger might provide more info.  

Anyone with educated guesses???

Ron Koval
chicagoland
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