John A. Tuttle wrote in 030105 MMDigest:

> Hi All, I'm the first to admit when I am wrong, and in the case of the
> QRS self-tuning piano, I was wrong about one point.  I now understand
> that the tuning is done by the tuner and then that tuning is 'saved'
> in the memory chip.  I stand corrected!
>
> Regarding the 95 degree (F) operating temperature, Ray Finch's comment
> made me laugh.  As a cat owner, I know that "Wiggens" and "Dit-Da"
> prefer warm places, and since a cat's normal temperature is about 101
> degrees, 95 degrees would be quite inviting.  So that means that I'll
> have to keep the piano closed up when it's not being used.  Now consider
> that I have some 250 steel wires at an ambient temperature of, let's
> say, around 85-90 degrees.  What is that going to do to the top of a
> grand piano?  [ It surely will attract cats!  :->  -- Robbie ]"

I too have no problem admitting when I'm wrong.  I must confess I am
not really a cat person.  I have owned dogs all my life.  I have only
had casual acquaintances with the feline species.  As such I did not
realize that cats would like such a warm place as a 95 degree heated
piano.  Any dog would be over heated in a mater of minutes (NOT that I
let my dog on the piano, mind you! <grin>).

> Until reading Robbie's comment, I hadn't thought about the consequences
> of heating and cooling the wires repeatedly.  I suppose that's why I
> asked the question, "How 'hot' is hot?"  As I recall from high school
> science class, repeated heating and cooling of steel is what is done
> to harden the steel, as for swords and knives.  Isn't that called
> 'tempering'?"

Sort of.  Heating and then quickly cooling tempers the steel to make
it harder.  Heating and then allowing the steel to cool (slowly) on its
own actually _softens_ the metal.  Any time you see a blacksmith in a
western movie working horseshoes he always plunges the red hot horseshoe
in cold water -- not only because it makes for a good dramatic effect
but because hardens the horseshoe.

However, repeatedly heating piano strings to 95 degrees is not likely to
cause any problems as a piano can very well get to that temperature on
a hot summer day and then cool down to 60 degrees or less at night.

This brings up an interesting point.  How will the piano stay in tune
on a hot summer day?  (Or much less, how will the house stay cool with
this room heater disguised as a piano heating the room!?)

Musically,

Ray Finch
Albuquerque, New Mexico (USA)

 [ I asked the piano tuners this question at the Sacramento Traditional
 [ Jazz Festival.  The festival owns 42 sturdy console pianos and most
 [ of them broil outdoors in the afternoon heat and then cool dramatically
 [ at night.  The tuners said that, when they touch up the pianos each
 [ morning before performances begin, the basic tuning pitch is unchanged
 [ from 24 hours before, so the job is mostly to bring the unisons back
 [ together after 12 or 14 hours continuous playing.  I conclude that
 [ these Everett console pianos withstand temperature cycling very well.
 [ -- Robbie