the A floats

[Dave Nereson]

----- Original Message ----- 
From: "Don" <pianotuna@accesscomm.ca>
To: "Pianotech" <pianotech@ptg.org>
Sent: Monday, August 30, 2004 11:36 AM
Subject: Re: the A floats


> Hi,
>
> Temperature wins out in the short term particularly the intense heat from
> stage lights. This can be ameliorated to some extent by "pre heating" the
> piano before it is tuned. It does require several hours for the piano to
> reach "steady state". If all the performance lights are on to do this the
> electricity costs far exceed the tuning costs.

    Really?  I've done a lot of stage crew work in full-fledged,
fully-equipped theatres, and came up with, very roughly, 50 kilowatts
beating down on the stage (but not all directly on the piano) with almost
everything except the follow spots burning.  Let's take even twice that, 100
kilowatts.  Electricity averages about 10 cents per kilowatt-hour.  So 100
kilowatts for an hour would be $10.  If they're all burning for 4 hours to
warm up the piano, plus 2 or 3 more hours for concert prep, that's 7 hours
times $10 equals 70 bucks for the juice, certainly less than the cost of the
concert tuning and prep.

> Air conditioning in halls in temperate climates in the winter time is
often
> done using "outside" air. Humidity can drop 30% in 15 minutes. It behooves
> the piano technician to find out "when" the air dampers will be opened and
> finish tuning before that event occurs.

    Good idea.  But air conditioning isn't used in the winter much.  But
even if outside air is pumped in for ventilation, it can be quite humid if
it's snowing or raining.  And even worse in the summer.  But as a rule,
doesn't air conditioning tend to dry the air, rather than make it more
humid?  (I know that swamp-cooler-type cooling makes it humid).  Yeah, air
conditioners drip water, so they must be removing it from the air.

  But no matter, the main question I have is:  how long does it take the
soundboard to react to that 30% drop (or rise) in humidity?

    People have asked me on rainy days if it's a bad idea to tune the piano.
I've always told them that just one rainy day isn't enough to throw the
piano out of tune.  Unless all their doors and windows are open.  In
general, I don't experience many customers all calling because their pianos
have gone out of tune unless we've gotten 2 or 3 weeks of rain almost every
day.  And when people turn on their furnaces in the fall, the pianos don't
drop in pitch in one day.  It takes a few weeks.
    You'd think there'd be scientific charts available, what with all the
research and technology going on nowadays.  Heck, even since the beginning
of the industrial revolution -- not much longer after the piano was
invented.
    David Nereson, RPT