Take a thin 6" ruler and slide it along the strings over the V-bar and under the edge of the pressure bar, so that it is flush with the bent segment of the strings going under the pressure bar. Then measure the elevation of the end of the rule above the string plane. Compare this measurement with one from a similar model piano that is working well. (I take this measurement before restringing a vertical piano, and duplicate it after restringing.) A rough guess would be that less than 1" elevation is getting low, over 2" is getting high. Someone with more experience or a more mathematical mind may be able to give more precise parameters. Ed S. -----Original Message----- From: David Ilvedson <ilvey@sbcglobal.net> Sent: Oct 8, 2005 12:14 PM To: ed440@mindspring.com, caut@ptg.org Subject: RE: [CAUT] Grease/Oil on upright pressure bar How does one check the amount of bearing under the pressure bar and what should it be? David Ilvedson, RPT Pacifica, California ----- Original message ---------------------------------------- From: ed440@mindspring.com To: "College and University Technicians" <caut@ptg.org> Received: 10/8/2005 4:53:19 AM Subject: RE: [CAUT] Grease/Oil on upright pressure bar >Andrew: >Your best chance of saving the current strings will probably be by loosening tension, >removing the pressure bars, and cleaning the bars and strings with rags and a solvent if >needed. This will be less labor than trying to clean under the bars with q-tips and rags, >and more effective. Be careful it does not migrate to the pinblock. >Someone mentioned checking the amount of bearing under the pressure bar, and that >is good advice. >It would be desireable to identify the lubricant before proceeding, and to have >records(photos and samples) in case it migrates and destroys the pianos. Please be >sure the faculty knows that this looks serious, and that you are trying to save the >instruments. >Some years ago I worked behind a self-trained technician who lubricated the bridge >tops with silicone paste. As it migrated, it ruined all the bass strings. No one in the >school thought it was odd, since all the pianos had thumping basses! "We're just a >poor college with worn out pianos." >Ed S. >-----Original Message----- >From: Andrew Anderson <andrew@andersonmusic.com> >Sent: Oct 7, 2005 8:35 AM >To: ilvey@sbcglobal.net, College and University Technicians <caut@ptg.org> >Subject: RE: [CAUT] Grease/Oil on upright pressure bar >Most do have evidence of lubricant to a greater or lesser >degree. The one that was the worst, so far, had terrible unisons >when I got to it. (I think the lubricant got all the way to the >bridge in the treble.) >The pin block is tight, the pins are "springy". The average humidity >is 60% Rh right now. In Laredo there aren't any mountains between us >and the cost so it doesn't get terribly dry >relative-humidity-wise. Think south-Texas. >So, this is a foreign substance. What is the least damaging way to >get it out? I've mentally debated trickling various solvents down >the wires over the bar into a rag below. I don't like that >idea. Another that came to mind is using the heat gun to mobilize it >with heat and forced air out of that position. That also has its >drawbacks, maybe less so than the first idea. Anyone have tested >ideas or want to hazard some opinions? >PRN =/= as needed >TAMIU = Texas A & M International University >Andrew Anderson >At 07:59 PM 10/6/2005, you wrote: >>Sorry for my ignorance but explain: PRN? TAMIU? If all of the >>Bostons, or majority of them have this stuff...sounds like someone >>lubed them. The factory isn't going put something in the piano >>that attracts dust/dirt. These are basically Kawais. You could >>have dried out pinblocks...Texas. Seems to me Avery can talk you >>through this... >> >>David I. >> >> >> >> >> >> >>----- Original message ---------------------------------------- >>From: "Andrew Anderson" <andrew@andersonmusic.com> >>To: "College and University Technicians" <caut@ptg.org> >>Received: 10/6/2005 5:24:07 PM >>Subject: [CAUT] Grease/Oil on upright pressure bar >> >> >> >Hi, >> >I'm tuning on a PRN basis for TAMIU here in Laredo. They finally >> >decided their black cages full of warbling songbirds and howling >> >seals needed a little discipline. (The grands are better, 50 to 80 >> >cents sharp on the top octave though, every piano.) >> >> >They have a bunch of Boston uprights (UP-125 II) that are proving >> >quite annoying. There is very little discernable friction between >> >the tuning pin and the speaking portion of the wire. I got >> >suspicious, went to the restroom and got some white paper. Swiped >> >the wires, yellow stuff, swiped the underside of the pressure bar, >> >more yellow stuff. Not very thick, but collecting dust anyway. When >> >I massaged the wires with the beat suppressor after the first pitch >> >correction pass I noticed that the wires were collecting a little >> >dust too, sticky. ... These are fairly new pianos, couple years at most. >> >> >When I say low-friction, I mean I can put my little hammer vertical >> >on a pin and walk a unison above and below tune without stressing my pinky. >> >> >Is this normal? Making unisons stable is a bit of a chore. No >> >wonder they were warbling & howling. Do they come from the factory >> >this way? or did one of the past piana toonas oil everything up? >> >> >Over lubricated in Laredo, >> >Andrew >> >> >_______________________________________________ >> >caut list info: https://www.moypiano.com/resources/#archives >>_______________________________________________ >>caut list info: https://www.moypiano.com/resources/#archives >_______________________________________________ >caut list info: https://www.moypiano.com/resources/#archives >_______________________________________________ >caut list info: https://www.moypiano.com/resources/#archives
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