VERDIGRIS IS COPPER CORROSION, GRRRRRRRRRR!

[Don Mannino]

At 05:36 PM 7/29/2005, you wrote:
>THAT'S NOT WHAT I ASKED !!!!!!!!!!!
>VERDIGRIS is an oxidation of COPPER without COPPER it
>CAN NOT EXIST!!!!! In the felt, or the pin. Probably
>the pin. So what is the composition of pins today, so
>that it can't arise. SIMPLE QUESTION!
>Sheesh!!!!
>      Thump

Sheesh, Gordon.  No need to yell.

The green oxidation is merely a side effect of the problem, not the 
problem itself, so your title statement is not correct.  Our term of 
"Verdigris" is just a term we use - it indicates contamination of the 
bushing, and we call it this whenever we see the green color, but 
really the problem is the contamination / gumminess, not the green.

So the paraffin and oil used, over time, did 2 things: They got thick 
and gummy, and they caused a chemical reaction which oxidized the 
copper (brass, really) at the same time, especially when combined 
with high humidity.  You can get the same effect by applying WD-40 to 
action centers - after many years it will gum up, and there will be 
oxidation of the brass as well.  It's not the brass causing the 
problem, remember, but the contaminant which was applied to the 
bushing.  If you eliminate the copper, the contamination and 
gumminess will still be there, the sluggishness will be just as bad - 
it just won't turn green.

To prevent the problem one must eliminate the contaminant completely, 
after which the brass pins should behave themselves.  My experience 
with many different cleaning solutions has not ever produced 
permanent resolution.  Some cleaning processes might give good 
performance for a couple of years, but those pianos which I have 
tried my best on have always gotten sluggish again after 1 or 2 
years.  That's why most people recommend replacing the parts 
completely as the best and safest solution to the problem.  Works every time!

I hope this makes the issue a little clearer, Thump.

Don Mannino RPT