sluggish centers

[Paul McCloud]

David:
I usually try a few with Protek, which doesn't always work, so I use the
shrink solution in that case.  Then I put Protek afterwards to "seal" them.
The Protek seems to provide some kind of waterproofing.  I've also found
that if I shrink the centers first, and they aren't loose enough, I'll put
Protek on them and they get loose real fast.  
Also, I've been plagued with sluggish flanges of late, and have found that
the most reliable way to get rid of sluggishness is to ream and repin. 
I've had several actions come back that had sluggish flanges which are
still getting sluggish after I did my usual shrink routine.  I believe that
the felt is too tightly pressed in the hole for a given humidity range, and
with a little extra moisture it expands and causes sticking.  If the piano
is in a damp environment, even if you dry it out, it will be a problem
later.  
I recently had to replace a set of flanges on a Kimball console.  The
flanges came without a centerpin.  I had to fit the centerpins to the
birdseye, and resize the flange bushings to fit.  The bushings were sooo
tight that I used a flame to heat the centerpin while it was forced into
the bushing cloth.  It ironed the cloth enough to make the flange loose
enough to use.  However, overnight the flanges became too tight, so I did
it again.  Same result- too tight the next day.  I finally used a reamer to
finalize the sizing process, and the result is still ok after a week.  
I have a "Zapper" which I made years ago.  (Newbies: a Zapper is a
contraption which uses a doorbell transformer to run a current through a
tight flange centerpin.  It heats the centerpin and "irons" the bushing
felt).  I  have been using it lately to help with the above actions.  I've
found that it works only temporarily.  I've had flanges that worked fine
after using it, and just out of curiosity, removed the centerpin to see how
tight it was.  The new pin was too tight.   This just reinforces my theory
that reaming and repinning is the way to go for permanent repair.
Regarding the use of alcohol and water, it is my understanding that the
alcohol does both, reducing surface tension and carry the water into the
felt.  It also dilutes the water, so it doesn't shrink the cloth too much. 
Straight water is too strong, and your flanges will end up too loose. 
Don't ask...
Hope this helps.
Paul McCloud
San Diego

> [Original Message]
> From: Dave Nereson <davner@kaosol.net>
> To: Pianotech <pianotech@ptg.org>
> Date: 11/05/2004 10:40:43 PM
> Subject: Re: sluggish centers
>
>
> ----- 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
>
>
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