On Jan 3, 2011, at 2:55 PM, Ed Sutton wrote: > More precisely, I almost always find piano verdigris in old Steinway > parts which were apparently treated by impregnation with paraffin or > some kind of oil, presumably to make the parts resistant to > humidity. I have also seen it in old Mason & Hamlin wippens, though > not to the extent it occurs in old Steinway parts. This would > supoort Susan Graham's comments about paraffin treated action parts > causing verdigris. Is there reliable evidence that paraffin was used by Steinway? I have always thought they used some kind of organic grease/oil, probably of animal extraction (mutton tallow being one candidate). Organic oils tend to get sticky over time, like linseed oil but true of other organic oils as well over a longer period. I don't think paraffin does so, though I could be wrong. Maybe there is paraffin that is less refined that could lead to problems. I have also thought the green color was leached from copper in the centerpins, and was more of a visual clue than an actual part of the problem. (I have an oiler I keep Protek CLP in. It has a brass spout, and the Protek gets green over time. I notice no problem with the Protek, and no sign of deterioration of the spout). I don't guess anybody has ever bothered to do a chemical analysis of the offending bushings? Nah, that would actually lead somewhere <G>. Regards, Fred Sturm fssturm at unm.edu http://www.youtube.com/fredsturm -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20110103/25bd3897/attachment.htm>
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