>While we're on the the topic of centerpins....has anyone come up with an >explanation for why some centers tend to freeze up (I believe the >offending pins were identified as being the German silver variety)? A >scientist here in Champaign had an explanation that seemed reasonable. >I'm trying to locate him for a quote... Anyone care to take a stab at it? I've noticed that often the way to get potential freezing hammer shank centres to seize on grands is to dust the knuckles with pure talc. Any talc that gets into the bushing area will seize them up almost instantly and completely. This happens particularly often on Yamaha and Kawai pianos, and I've noticed that often the pinning is "backwards", ie: the pin is tight in the bushing and loose in the wood. It appears to me the talc gets into the wood and adds enough friction to seize the pin. If the pinning is correct this doesn't seem to happen and it doesn't seem to happen again after repinning.. On the other hand, I have a Chickering grand I look after where the pins seize all the time, even after repinning. On this instrument it appears to be contamination of the bushing cloth somehow. I have since lubed it with CPL (the new stuff) and it seems to be much improved. This seems to be unrelated to the Asian piano problem though. Just a thought... John Musselwhite, RPT - Calgary
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