[CAUT] How long to stabilize??

[Ron Nossaman]

Diane Hofstetter wrote:
> I know many of you have written in the past about the problems 
> with tuning stability in brand new loaner pianos from manufacturers.  
> Fortunately the college where I am tuning has purchased these pianos, so 
> they won't disappear just when we get them settled in.
>  
> However, my question is this; in a practice room in a small college, how 
> long, or how many tunings do you think it will take for the school's new 
> Kawai UST-9's  to stabilize in tuning? 
>  
>  The pianos were  delivered directly to the college from the warehouse 
> and uncrated there.  Before that they spent two days in the truck. It 
> was snowing outside. 
>  
> They have Dampp Chaser heating rods and HD humidistats installed, but my 
> data logger, which was in their new Boesendorfer between December 4 and 
> February 4, showed nothing but too dry.  Every time I have tuned in the 
> practice rooms, my humidity gauge reads 36-38% RH.  I do expect the 
> humidity to go up to around 60% in the spring.
>  
> Each piano has received one pitch adjustment--usually pitch raises, but 
> two of them took lowering--and one tuning since the beginning of 
> February when they were delivered.  Already I want to tune a couple of 
> them again, but this is not in the budget or mindset of either the store 
> that sent me out or the college who now owns the pianos.  They all think 
> the tunings should be stable already.
>  
> Experienced opinions gratefully received!
> Diane Hofstetter

"It's a new piano, why would it need tuned so much?" Repeat ad 
infinitum. I don't think I've ever met a new piano that didn't 
need 1/4 semitone or more pitch raise during it's first year 
on site. It's not the time between tunings that counts, as 
much as the number and range of humidity swings. It's the 
humidity related dimensional changes that compact wood and 
lower pitch. The more tunings it gets the first year, the 
smaller the incremental pitch changes with each tuning, but 
the total after a year is about the same in any case for a 
given climate. Lowering pitch in a "right off the truck" 
instrument just adds that pitch change to the required pitch 
raise(s) for the next year. If the facility isn't getting 
below 36%in the winter, or above 60% in summer, you are well 
and truly blessed. But you'll still have to raise all those 
new pianos a quarter semitone to pitch between now and next 
February. The heater rods will certainly help in the summer, 
so you won't be lowering pitch dramatically in the low tenors, 
making the autumn pitch drop that much more traumatic.

So the answer to "how long" is at least a year, after which 
the pitch in various parts of the scale will be fairly well 
correlate with the humidity cycles.
Ron N