I'm in San Francisco. I've been tuning for this person for awhile. He had a Kawai before and recently bought a S&S. He is a good player with high expectations for the instrument (who wouldn't have after $60,000). I measure the humidity whenever I tune and he also has a hygrometer in the room. The range has been from 30% to 80%. The house has radiator heating which can be very drying. San Francisco, otherwise, is a very humid environment, though cool. He ran a dehumidifier in the room for awhile but it was not terribly effective in an open environment, it was noisy, and it burns a lot of energy. The house does not have central air into which a dehumidification sytem might be installed (though expensive). A DC system will be the best alternative. I was pleased to read Ruth Phillips' post which echoed my concerns about stability for the sake of consitent action performance and gave me some ideas as to the best way to approach the problem. My general plan is to start with a standard two bar system under the soundboard and a 15 watt under the keybed. I have taken some sample readings on flanges and will compare after 6 weeks. If not effective I will increase to 25 watts under the keybed. If that still proves ineffective, I will add replace the keybed bar with 15 watts and add an 8 watt bar inside the action cavity with a separate humidistat. All this with accompanying covers. Once I feel the action has achieved some type of equilibrium, I will address the uneveness in the flange pinning by reaming and repinning. Will probably do this in conjunction with addressing action leverage problems. Unfortunately, I believe that this is another plate indexing problem in which the capstan is located too far back and the ratio is just too high producing a very heavy feeling action. Though I have not surveyed the action thoroughly, my sample readings and experience suggest that this is the problem. For the moment, the dealer techs are still looking at it trying to convince him that the piano falls within "normal" guidelines. So far, he is unconvinced. David Love davidlovepianos@earthlink.net > [Original Message] > From: Farrell <mfarrel2@tampabay.rr.com> > To: Pianotech <pianotech@ptg.org> > Date: 8/27/2003 7:25:38 PM > Subject: Re: Dampp Chaser and Grand Action > > David: How about a little background on this one? It sounds interesting to follow. You indicate that you have monitored the indoor environment for a year - what data do you have available - what have the humidity swings been? What area of the country are you in? Is the new home air conditioned? What kind of heat? Does the home have a humidifier? Might it have whole house humidity control (not bloody likely, I suppose). > > Have you been able to document touchweight during dry conditions, and then touchweight during high humidity conditions? > > Thanks. > > Terry Farrell > > ----- Original Message ----- > From: "David Love" <davidlovepianos@earthlink.net> > To: "Pianotech" <pianotech@ptg.org> > Sent: Wednesday, August 27, 2003 12:31 PM > Subject: Re: Dampp Chaser and Grand Action > > > > This sounds like the most reasonable suggestion which I will try. The > > piano is a new NY S&S B. The piano, when moved from the showroom (air > > conditioned) to its new residence (high humidity at present, but showing a > > wide range of fluctuation on the hygrometer over the past year), became > > quite stiff. Sample measurements of up and down weight show friction > > readings ranging as high as 20 grams on some notes. Most of the problems > > on the measured notes seem to be in the hammer flanges. Jacks are also > > sticking and a precise adjustment of the repetition spring is impossible > > with these types of humidity swings. At present, as you can imagine, the > > piano also has repetition problems. While treating all the flanges is an > > option and may be necesssary, if only to provide even resistance, I prefer > > to try and stabilize the humidity and create some kind of baseline before > > doing that. While I understand the downside potential of putting a heater > > bar in the action cavity, it seems that the problems reported have occurred > > mostly with high wattage bars without humidistat control. If we set too > > much downbearing and the piano sounded like crap, you wouldn't choose to > > avoid using any downbearing in the future. Many of the things we do > > operate on the edge of disaster if not regulated properly. That doesn't > > mean we shouldn't do them. It's unfortunate that there isn't more research > > on regulating humidity within the action cavity itself. Perhaps the > > manufacturer will see fit to conduct that kind of research. It's beyond me > > to do it at the present time. However, it's certainly an important area to > > control. Since this seems to be an area of uncertaintly, I will opt for > > the under-the-keybed position and hope for the best. > > > > BTW for you touchweight enthusiasts, FWs = 85% max on average with BWs > > between 45 and 50 grams. Add a little high friction and DWs were near 70 > > grams on some notes. Nice.... > > > > David Love > > davidlovepianos@earthlink.net > > > > > > > [Original Message] > > > From: Tony Caught <caute@bigpond.com.au> > > > To: Pianotech <pianotech@ptg.org> > > > Date: 8/27/2003 11:32:09 PM > > > Subject: Re: Dampp Chaser and Grand Action > > > > > > Thank you Robin, > > > > > > I was about to suggest the same about fitting a rod under the keyboard, I > > > have done the same in Darwin Australia and have never had further problems > > > with sticky actions. > > > > > > Some one once said that you don't fit Dampp-Chasers to fix sticky actions, > > > only to keep the pitch constant but believe me, the customers just want to > > > play their pianos knowing that the piano is out of tune a little (or a > > lot) > > > is natural in this humid weather. > > > > > > It Works > > > > > > Tony Caught > > > Adelaide Australia > > > caute@bigpond.com.au > > > > > > ----- Original Message ----- > > > From: <DCrpt@comcast.net> > > > To: <davidlovepianos@earthlink.net>; "Pianotech" <pianotech@ptg.org> > > > Sent: Wednesday, August 27, 2003 10:04 AM > > > Subject: Re: Dampp Chaser and Grand Action > > > > > > > > > > I was trained in Dampp Chaser installation by Wendall Eaton.(Well > > > known > > > > consultant and Dampp Chaser distributer back in the 80's).He taught me > > to > > > cure > > > > sluggish keys and action centers in a grand by mounting a 7-F (15 > > watt)on > > > the > > > > underside of the keybed just in front of the top of the pedal lyre and > > of > > > > course connected to a humidistat.I have done this on many > > > installations(most > > > > all with complete systems)and have not seen any problems in over twenty > > > > years.The principle of heat rising through the key bed helps keep the > > keys > > > and > > > > action dry with out heating the pinblock.I have found it also stabilizes > > > > Stienway key frames so the glides stay regulated. > > > > I will add that it is an absolute no no to put a rod of any > > wattage > > > > inside the action cavity. Robin Olson RPT > > Wash > > > DC > > > > P.S. for some reason my e-mail server does not include my return > > > > adress on replies to the ptg list.Sorry if that bothers any of you. > > > > > > > > > _______________________________________________ > > > pianotech list info: https://www.moypiano.com/resources/#archives > > > > > > > > _______________________________________________ > > pianotech list info: https://www.moypiano.com/resources/#archives > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives
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