Del, I think we were talking about the crown of the bridges not the ribs. John Delwin D. Fandrich wrote: > ----- Original Message ----- > From: "Greg Newell" <gnewell@ameritech.net> > To: "Pianotech" <pianotech@ptg.org> > Sent: Saturday, April 12, 2003 8:02 PM > Subject: Re: Killer Octave Question > > > >>>If the crown was created by being deformed for many years we would see >> > all > >>>piano makes with this feature. If this were so they all would have >> > crowned > >>>bridges. But clearly some makes have crown and others don't. >> >>Good point! I haven't seen enough of them to make this comparison. > > > Not necessarily. It would depend on how rapidly the original board lost its > compression-crown. If the original board was set up (in NY or wherever) on a > dry day with a fair amount of string bearing and then sent to a relatively > humid climate it would deteriorate quite rapidly. There would not be enough > time for the ribs to take on a set themselves. On the other hand if the > board were originally set up on a humid day and with light string bearing it > would last considerably longer. As to whether this would be long enough for > the ribs to take on a set or not I can't say. I have pulled ribs off of old > Steinway boards that indicated some slight amount of curvature. (I would > call 1/8" curvature on a long rib "slight.") Both up and down. I'm not > prepared to say just where this curvature came from. Steinway has > traditionally installed flat ribs. While it is certainly possible for a flat > rib to warp though it would be unlikely for three or four adjacent ribs to > warp in the same direction. > > Del > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives > > -- John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor
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