sluggish centers

[Dave Nereson]

----- Original Message ----- 
From: "William R. Monroe" <A440WRMPiano@tm.net>
To: "Pianotech" <pianotech@ptg.org>
Sent: Friday, November 05, 2004 8:36 PM
Subject: Re: sluggish centers


> Dunno,
>
> But let me add to the question.  Do we first lubricate then shrink if
> necessary, or shrink, then lubricate?  I've done it both ways, but wonder
> what others think.  I generally go for lubing first, that almost always
> frees everything up.  Which would be the "proper" order on this one?
>
> William R. Monroe
> Madison, WI
> Assoc.

       I would think it's a matter of degree.  After Protek-ing a few of 
them,
they loosened up a bit, but some were so tight, it didn't have any effect.
      I'd say if they're just a little sluggish, try lube first.  But if
they're quite slow in returning, shrink the bushings with alcohol/water.
    Overshrinking is definitely possible.  I did it once using just water, 
no alcohol.

    But wait a minim -- why do we mix it with alcohol, anyway?  Is the 
alcohol spose to help carry the water into the felt?  Or does it lower the 
surface tension of the water?  Or does it make the solution have a less 
drastic effect than straight water?  I LIKE the surface tension because it 
allows me to "hang" a droplet on the side of the bushing, or to "stretch" 
the droplet between adjacent flanges, where it sits until it soaks in, 
wheareas with the surface tension lowered, it tends to just run down the 
side of the flange.

    Once I put one of those sluggish actions in the hot summer sun for a few
hours, went and tuned someone else's piano, came back, and they were all
freed up enough for me to tune it.  (This was in a piano that had been
unused in a basement for a long time).
    --David Nereson, RPT