Center Pin Question

[David Nereson]

Thomas Cole wrote:

> I have a piano in the shop which is being prepped for sale. It happens 
> to be a Wurlitzer model 200A electric piano, low miles but the action 
> was a little sluggish and I couldn't regulate it because of tight 
> centers. I've repinned and Goose-juiced hammer and wippen flanges and 
> noticed that all of the center pins had a blue-green coating on the ends.
>
> I've been monitoring the Wurlitzer Electric Piano list and some people 
> are saying yes, use silicone to free up the action and others are 
> saying that piano techs recommend against silicone. Didn't Wurlitzer 
> recommend using silicone / naphtha to lube the centers? Has anyone 
> noticed a similar verdigris problem on Wurlitzers or other 
> non-Steinway pianos? What would cause such a corrosion?
>
> Thanks,
> Tom Cole
>
>
>
> _______________________________________________
> pianotech list info: https://www.moypiano.com/resources/#archives
>
>
Whoo, boy -- check the Archives for "vertigris."  There are volumes and 
volumes of discussions on this topic.  Yes, Wurlitzer reps at one time 
recommended using the silicone/naphtha mix or mineral oil/naphtha, but 
the general consensus now is that, like mildew, it will return.  So the 
only long-term solution is to replace parts.  Short term, starter fluid 
(auto parts store) works pretty good for appearing to dissolve it.  The 
cause is still being debated, but it must be some chemical reaction 
between the brass plating of the center pins and something in the felt 
of the bushing cloth. 
    --David Nereson, RPT