[pianotech] What is this?

[John Delacour]

At 13:27 -0700 17/5/10, Matthew Todd wrote:

>This link should work!  Anyway, I would appreciate thoughts as to 
>what this is.  The piano is a Kimball.
>
><http://farm5.static.flickr.com/4027/4616647986_6f5a441ac5.jpg>http://farm5.static.flickr.com/4027/4616647986_6f5a441ac5.jpg

It is a salt or a mixture of salts of copper, commonly called 
verdigris, caused by chemicals in the atmosphere reacting with the 
copper in the bronzing powder.  This would not happen if the bronzing 
had been effectively lacquered over with an impermeable lacquer.

JD

-- 
______________________________________________________________________
   Delacour Pianos  *  Silo  *  Deverel Farm  *  Milborne St. Andrew
                      Dorset DT11 0HX  *  England
                        Phone:  +44 1202 731 031
                        Mobile: +44 7801 310 689
______________________________________________________________________