[pianotech] Sealing the air leak on a Duo-Art takeup spool

[Ron Nossaman]

On 3/18/2012 8:20 PM, Duaine Hechler wrote:

> That is the reason for my question, I have not had the experience of
>  seeing a proper setup. The one I am about to service just has the
> metal on metal connection. There was no washer stack of any kind in
> the spool end.
>
> Please, explain the proper leather washer stack for the spool end.
>
> Thank you, Duaine


After I sent that, I realized you said Duo-Art instead of Ampico. The 
Ampico has a stack of thin leather washers in the end of the spool 
acting as a rotary seal. It's been a long time since I've worked on a 
Duo-Art, and don't remember specifically what's there. Ok, I found a 
hosing diagram, but not something showing the replay valve. The shutoff 
hoses into the tracker. In the Ampico A, the opening is on the take up 
spool. Isn't the Duo-Art triggered by a lever dropping into a notch in 
the take up spool to open a valve? Whatever the details are, you need an 
air tight seal from that valve opening to the valve, through the metal 
rotation valve and another set of control valves. It's going to take 
spending the time to diagnose it, track down the leak(s) and make a real 
fix. There may be a magic bullet quick fix that experts use, but I'm 
only a mechanic and have to do it the hard way.

Ron N