Verdigris is a greenish coruscation (as you might see on bronze statues) on and in the centers of pianos resulting from chemical interaction between the metal of the pin and the lanolin in older bushing felt. Modern felts and modern pins generally don't suffer from this. Humidity has nothing to do with the creation or exacerbation of verdigris. Paul In a message dated 1/2/2011 6:28:46 P.M. Central Standard Time, kolsonpiano at verizon.net writes: There can be a condition known as vertigree. Center pins there are usually four on every note or key can corrode. This corrosion makes the action sluggish. Advanced vertigree will render a piano action useless. Vertigree comes about after exposure to high humidity. Kevin Olson, piano tech. Manhattan School of Music. Jan 2, 2011 03:33:33 PM, caut at ptg.org wrote: =========================================== Hello, The University of Wisconsin-Parkside has had extreme humidity issues the last six months. In the course of connecting utilities to our new building, our air handling equipment has been shut down without notice. During the summer, the humidity was 80% for at least five weeks, and this fall it dropped to 20% for at least two weeks. The damage to historic reproduction instruments is obvious—snapped strings and soundboard cracks. But our 30 modern pianos are a problem. I have been told that damage may not be apparent for a year or more, but the insurance adjustor wants to settle now. We have 38 year old Yamahas and Baldwin Hamiltons. Other pianos are a mixture of pianos newer and rebuilt from the last 25 years. I am in need of statements from technicians concerning the invisible damage that could have happened. I need to be able to propose a settlement which will take into account future damage. Thanks for any assistance you can provide me! James McKeever Professor of Piano Chair, Music Department University of Wisconsin-Parkside Kenosha, Wisconsin -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20110102/599bcb8e/attachment.htm>
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