> > Rob, > > Where were the rods positioned? One under the keybed? I usually put a 50 > watt under the soundboard and a 25 watt next to the lyre base under the > keybed (on the action side). I've not had these action problems. I see a > lot of Samicks/DH Baldwins/Kohler & Campbells. After the damper guide > rails, keys, and action centers are eased, they usually stabilize for me. > Greetings from Humidityville! > > Lance Lafargue, RPT On grands, I do the standard install recommended by Dampp-Chaser, humidifier in the centre of the soundboard, de-humidifier right behind the keybed, parallel to the belly-rail. There was a time when I was installing the de-humidifiers along the soundboard, roughly following the treble bridge buttons, but I've since stopped. The idea was to have the de-humidifier as close to the bridge area as possible, ostensibly to 'stabilize' the board and keep the bridge from rolling, but I've found no evidence that this works or not! >Hi Rob & List: I have been servicing and tuning pianos some >thirty-five plus years, now semi-retired (which is perhaps one of >the finer aspects of piano tuning). During the course of my >endeavors, I have installed some sixty D.Chaser units. >The geography of those D.C units is n.e. Colorado/western Nebraska. >Never have I seen a piano when D.C. equipped develop tuning pin >troubles. In addition I have seen several so equipped pianos, >particularly in upright models, where D.C.s definitely helped the >loose pin problem >In addition for some nineteen years I have tuned part time in the >Phoenix/Tempe during the winter seasons where Jim Coleman >families reside. Pianos in homes equipped with both water and >refrigeration air conditioners are definitely aided by just a >humidistat and one(or more) dampp chaser dehumidifiers, even grands. >Pianos so partially equipped eliminate the problem adding water all >the time. Thanks for 'listening' !! > Clarence Thanks for your insight, Clarence. I'll have to keep checking these instruments over the years, and compare the results! Tim Keenan wrote: >I have not made a statistically valid, replicated study, so this is >anecdotal only. Before moving to near-coastal BC, I lived in >Southern Ontario. RH in summer is *often* above 80%. Indoors, in >winter, it is often below 20%, because it is being raised 40 degrees >C or so (about 85 degrees F.) from the outside temperature. In >older upright pianos in particular (Heintzman, Bell, Martin-Orme, >Henry Herbert, Gourlay--1910 to 1935 vintage (maybe because of >fewer/thicker pinblock laminations?) there is often a discernible >difference between mid-summer and mid-winter pin torque. In several >cases where the instruments were in otherwise tolerable mechanical >condition, but the pin torque was marginal in winter, there was >enough of an improvement with installation of a D-C system to put >off repinning, at least for a few years. >Rob--I'm a prairie boy, and I know about the climate in Edmonton. I >am not too surprised that you would not see such a difference there. >I think that the *amplitude* of humidity fluctuations contributes to >loose pins more than absolute dryness does. I think the >illustration in the new D-C promo video is pretty good. Swelling of >the pinblock by high summer humidity could conceivably cause some >crushing of the wood cells at the pin/wood interface, and this would >leave the pins that much looser at the dry end of the cycle. That makes a good deal of sense... the wood is enlarged, contracts, and loose pins develop. With proper humidification, and _de_ humidification, this problem is minimized. Again, I'll have to keep closer watch on some of these DC installed units when tuning, to see what patterns develop. I know some pianos where the de-humidifier bar is practically never on. Thanks everyone, it's been enlightening hearing reports from other areas, and re-assessing my assumptions about these units. Happy Monday, Rob Kiddell, Registered Piano Technician, PTG atonal@planet.eon.net
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