Greg, Thanks for saving me the time to write in on this subject. I could not have said it any better. Al Guecia From: Greg Graham Sent: Tuesday, June 03, 2008 10:38 PM To: pianotech Subject: Pinblock contamination: myth? The recent thread on how to deal with a few low torque tuning pins in a new block stirred up the "pinblock contamination" concern. I was talking to another tech who maintains a few (not one, not two, but several) Steinway D's with loose pins in the low bass. Touch the tuning hammer and off they go type loose. One or two of the pinblocks are rebuilds, maybe 10 years old. I wondered why he didn't try a light application of CA to solve the problem. He said, "I'm waiting for the right time to use larger pins. I don't want to contaminate the blocks." How does CA "contaminate" a pin block? I think of it as adding some density to the wood. It is inert. It does not attract water and rust pins like the old pin tighteners did (and still do!). It seems like removing a big bass string from a tuning pin, cranking out the old pin, and pounding in a new one is much more invasive and risky (to the string), and certainly more expensive, than just a couple drops of CA. You certainly could pound in a larger pin if the CA didn't work, right? Use of larger pins assumes the hole was somehow larger than it should have been, either because of localized lower density of the block, or perhaps a hot, dull, or clogged bit toasted or enlarged the hole. We assume the larger pin is a permanent fix, and thus the "right" repair. But if the defect is a void or crack, wouldn't a larger pin make the problem worse where CA would help fill voids and prevent crack propagation? If the problem is low wood density, wouldn't CA increase the density? What, exactly, are the risks? How does CA damage, contaminate, or in any other way render a pinblock (new or old) less functional, now or in the future? Does it reduce resiliency? Will the wood not be able to handle the seasonal movement, causing long term looseness, even if a larger pin is installed later? Are we concerned about jumpy pins? My experience is limited, but I have not seen CA cause jumpy pins. Have I missed out on the fun? Does the CA turn the tuning pin into a bumpy reamer which destroys the hole over time? (I've heard that suggested, but never pulled a pin to see for myself. I doubt it.) Are we concerned that there will be visible evidence of the CA on the plate or bushings that would cause someone to doubt the quality of the piano, thus lowering sale price? I'm not talking about old blocks, and I'm not talking about heavy amounts of CA. I'm asking about new blocks with a few problem pins. What is the risk of a light application of CA to the low torque pins? And how could this possibly "ruin" a piano? Greg Graham Brodheadsville, PA -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080604/40970b1c/attachment.html
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