lubricant

[Rolland Miller]

Thanks for a good explanation Paul.  Rolland Miller, MPT/PTG

Paul S. Larudee wrote:

> JIMRPT@AOL.COM wrote:
> >
> > "Verdigris" is  a green waxy build up as evidenced on action
> > centers/pins/flanges bushing cloth. The buildup of this substance eventually
> > causes problems in repetition/regulation/playing. The definiton of "Verdigris
> > is : "A green patina or crust of copper sulfate or copper chloride" In pianos
> > this sulfate/chloride is normally accompanied by a waxy substance.
>
> "Verdigris" is a Languedoc word (Provencal, spoken in southern France,
> is a modern descendant of Languedoc) which best translates as "grayish
> green."  It is rust - specifically corroded copper, which is one of the
> metals in the alloy used for center pins - and can be caused by
> corrosive agents like sulfur or chlorine.  Since rust is porous, it can
> absorb other substances like the lubricants used to treat (or mistreat)
> action centers, or whatever chemicals may remain or have been
> deliberately introduced into the bushing cloth.  A chemical reaction can
> sometimes take place between these substances and the corrosive agents,
> the result of which is usually a thickening of the substances.
>
> Polymers are highly stable long-chain molecules which for all practical
> purposes will react with almost no chemical, and certainly not with
> anything encountered in action centers or anywhere else in the piano.
> Their only effect is to reduce the friction of whatever they coat.
> Protek CLP therefore makes the corrosion and whatever other gunk (an
> esoteric technical term) may be there slipperier than it would otherwise
> have been.  Furthermore, the slipperiness is long term, because of the
> stability of the polymers.
>
> Probably more than anyone wanted to know.
>
> Paul S. Larudee, RPT
> Richmond, CA