brass v. iron

Don drose@dlcwest.com
Thu Dec 3 17:33 MST 1998


Hi Conrad,

The concert hall here has a bit of an unusally cooling system. In the
winter they draw outside air for cooling. Which causes the humidity to
plunge, which within 15 mins causes the Steinway D to drift. They start
this proceedure of cooling one hour before show time. Wow betide the tuner
who isn't finished before the cooling begins.

So I would disagree that humidity is *not* a factor. I would also disagree
with Roger how ever. You can give repeateable phenomina predict what the
wood will do. (Atleast to the tuning).

At 01:58 PM 12/3/98 -0600, you wrote:
>Well, Dr. Pangloss, a.k.a. Roger,
>
>At 13:22 12/3/98 -0600, you wrote:
>
>>Hi Conrad,
>>                The numbers would be good IF you had an absolutely stable
>>bridge and sound board, I seriously doubt that you could relate it to cents
>>because of this factor. 
>>I agree with all your points with regards to predictibility of coefficients
>>to metals, since heat transfer is also and rate of expansion is
>>predictable, but trying to predict lumber??????? in tems of cents, now that
>>is a challenge.
>>I'm smiling not picking.
>
>Wouldn't you say that in this best of all possible worlds, I could ignore
>other confusing factors.  (facts?)
>
>That said, in this situation the time factor (1/2 hrs?) involved would
>pretty much eliminate any wood temperature expansion coefficient anyway.
>Even over time, the dimension change of wood seems negligible.  Methinks
>the parameter which would be more critical to wood dimension changes would
>be humidity spike induced by breathing of the audience. Even then, I don't
>think there "wood" be enough time for even that to make a difference.
>
>Still smiling ;-}
>
>
>
>Conrad
>
>Conrad Hoffsommer 	mailto:hoffsoco@luther.edu
>Luther College		(319)-387-1204
>Decorah, Iowa 52101-1045
>
>The best things in life aren't things.
>
>
>
Regards,
Don Rose, B.Mus., A.M.U.S., A.MUS., R.M.T., R.P.T.
drose@dlcwest.com
http://www.dlcwest.com/~drose/
3004 Grant Rd.
REGINA, SK
S4S 5G7
306-352-3620 or 1-888-29t-uner



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