Jeff Tanner, CAUT, 2/20/09 Jeff, The three days was an estimate/guess of the 30’s in construction and rather continues in more massive woods, hence my applying it to pinblocks. My humidity experience ranges from one day to many days or months. Our summer workshops lasting for two to four weeks could manage quite well in July with a shop ambient humidity of 52° to 55° for the whole period (such good fortune) measured continuously by a scientific blond hair hygrothermograph. The rest of the year was similar to yours only a little less due to the moderating effect of coastal weather. The truly frustrating humidity occasion occurred just before the beginning of the school year: the piano professor demanded that the Hamiltons be tuned before the beginning of classes, that done the humidity would change by 60° and all the pianos could produce a fair chromatic scale but each piano was very unacceptably out of tune. What caused that is good for surmise a la piano history But the point of my last contribution was the affect by humidity and temperature during the period of concert prep/concert/intermission/ finale in which humidity appeared to affect the pinblock in that hour to two hours of the early portion of the concert. To repeat the earlier statement, the pinblock was measured (by micrometer) as changing in dimension front to back by thousandths of an inch to affect unisons. It turned out to be a good test of unison tuning and also the firmness of plate/web screws which did not have a large effect. Dan Gurnee On Feb 20, 2009, at 9:18 AM, Jeff Tanner wrote: > Hi Daniel, > Our recital hall at S Carolina experienced very similar results as > those you observed. My tuning time in the hall was originally > first thing in the morning as had been established by my > predecessor. It didn't take me long to learn that what I tuned in > the morning had often dissipated by the time the recitals began at > 4:30. > > In response to your statement below, I'd like to throw in my > observations. Perhaps I am misinterpreting your perspective. In > South Carolina, we really never experience a gradual change in > humidity. It's not there one day, the next day it is here, and > here to stay (except for during the school year, of course, which > can reveal 55% today, 27% tomorrow, 48% the next, etc). But once > the end of the school year rolls around, we've generally and > literally jumped to 60%+ RH (in the humidity "controlled" recital > hall -- rooms with no humidity control and occupants who sweat > profusely at 65 degrees would see RH as high as 80%RH and just > below), and it remains there until late in the fall semester, when > it simply nosedives after Thanksgiving just in time for juries. > What I observed during the summer months in the recital hall, even > after a month or so at the upper end of the humidity range, is that > the pitch continued to climb, even having "stabilized" the > instruments for a week during July for a piano festival. The pitch > continued to creep upward through September before it began to > stabilize, and that perhaps only because we were tuning again on a > regular basis, holding the pitch down. > > I also observed one occasion in the recital hall when I felt and > smelled the humidifier come on during a tuning. I watched as my > hygrometer lying on the piano began to change numbers like tenths > digit on my car's odometer going down the interstate. I also could > measure the pitch changes minute by minute as the humidity > increased. I stopped tuning, put my tools in my bag, and went and > reported the obvious malfunction. > > So, I'm not quite sure what you mean by 3 days. > Jeff Tanner > ----- Original Message ----- > From: Daniel Gurnee > To: Ed Sutton ; caut at ptg.org > Sent: Friday, February 20, 2009 11:33 > Subject: Re: [CAUT] Detuning phenomenon; was: How long to stabilize?? > > Humidity wise, it has been generally understood that humidity will > affect wood by three days. > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut_ptg.org/attachments/20090220/c8f75f63/attachment-0001.html>
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