[CAUT] A record low humidity reading, for me

[Fred Sturm]

Hi David,
	I regularly get readings of 2.5 - 4.5% in winter at a private school  
I service, using the same Mannix hygrometer. (Outside on a hot summer  
day, and in a solar heated car, I get below 2%.) At my university, i  
get below 10%, but haven't yet dipped below 5%. In any case, yes,  
pianos survive those conditions. Things happen: plastic keytops  
develop hairline cracks (just a visual problem, they're not pulling  
loose); keyslips become difficult to remove because they are longer  
than the gap is wide (and other similar fitting issues); and, yes, a  
few soundboard cracks appear, though far less than I would expect.
	The RH doesn't get above 60% generally, and the high end of the  
season is fairly short, and I think this is a big help: the wood  
doesn't swell enough to crush fibers. Some pianos that come, say, from  
England simply fall apart. I had to remove the lid hinge ("piano"  
style) from a Broadwood grand and cut/file away a total of at least 1  
cm of brass so that it would re-install lying flat. And there is  
buckling of veneer. But the piano is fine.
Regards,
Fred Sturm
University of New Mexico
fssturm at unm.edu



On Dec 8, 2008, at 8:26 PM, David Skolnik wrote:

> Dear List-oires -
> I don't generally take the time to simply "share" some experience,  
> unless there's a particular point I'd like to make, or question to  
> ask.  This time, it's just sharing.
>
> My current psychromatic tool of choice is an upscale version of the  
> one Pianotek shows on page C-1 of their catalog.  It is a Mannix  
> (now General) EP8706, which claims to be accurate to +/- 2% as  
> opposed to 5%, and which can be re calibrated by the user (me).   
> I've checked it against a more expensive gauge and it seems quite  
> close.  Today, in a couple of public school buildings, I got  
> readings as low as 4.5%.  I breathed on it to make sure it wasn't  
> broken, or I wasn't dead.  Neither was the case.  I know, within the  
> context of the recent thread "What to do", Jim Busby said that his  
> collection of some 420 instruments is frequently exposed to levels  
> lower than 10%.   That seems disturbing enough, but how long would  
> anything last, with extended exposure to 5%?
>
> Anyway, I was impressed.
>
> David Skolnik
> Hastings on Hudson, NY
>

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