Mechanical Music Digest  Archives
You Are Not Logged In Login/Get New Account
Please Log In. Accounts are free!
Logged In users are granted additional features including a more current version of the Archives and a simplified process for submitting articles.
Home Archives Calendar Gallery Store Links Info

Spring Fundraising Drive In Progress. Please visit our home page to see this and other announcements:     Thank you. --Jody

MMD > Archives > December 1997 > 1997.12.17 > 19Prev  Next

Rejuvenating Bellows Cloth
By John A. Tuttle

Good Day to All,  This posting is directed primarily to any of the
chemical engineers and/or members with a background in chemistry.

I'm certain that at some time in every player piano technicians career
he comes across devices within the player mechanism that "look"
perfectly good.  Since the late 80's, I've encountered numerous Aeolian
air-motors that operated erratically, or 'loped' (as I call it).  The
problem is simple....  lack of use.  The repair..  not so simple...
rebuild the air-motor.

Having recently passed a solid twenty years in business, I'm now
encountering units that I've rebuilt that suffer from the same problems
as the 20-year-Aeolian.  Namely, stiff air-motors.  I've used many
different types of cloth to recover air-motors and I do find that
certain types of cloth seem to retain their suppleness better than

However, the ones that remain supple are thinner and wear out faster
than the thicker cloth.  So it's kind of a double-edged sword.  And
since there is no way to predict how much usage a particular unit might
get, it's virtually impossible to select an optimum cloth.  Further,
the availability of cloth changes over the years making it even harder
to reproduce the same quality (i.e. life span) work year after year.
But on to my point.

In my earlier years, I tried everything under the sun to rejuvenate
cloth (that had only the very smallest pin hole leaks at the stress
points) which had become stiff due to age.  You name it, I tried it.
Much to my dismay, nothing ever worked for more than a few days before
getting stiff again (and often stiffer than it was before I did
anything).  At some point in time, I finally 'gave up the ghost' and
just started telling people to either use the unit 10-15 minutes a
month or face the reality that the air-motor would have to be rebuilt
'before' it actually wore out.

Yesterday, while using Goo Gone to clean some adhesive off an air-motor
governor that had been 'repaired' using tape (yuk!).  I decided to put
some Goo Gone on the 'stiff but rather intact' air-motor cloth just to
see what would happen (I'm rebuilding the air-motor anyway so it was
just an experiment.  The Goo Gone was just handy at the moment).

Much to my surprise, the material seems to soften right up so I applied
it (sparingly) to the rest of the bellows and tested it.  Hmmmmm! It
ran smoothly with less than 10" of vacuum.  (When I tested it at the
customers house, I had to suck it with at least 25" just to get it to
move and even then, it loped very badly).  Naturally, I don't plan to
leave it for too long before rebuilding it but I'll leave it a few more
days just to see if it gets worse or stays about the same.

Now to my question.  With all the new chemicals reaching the market
today, are there any you can think of that might be used to rejuvenate
dried out player bellows cloth without breaking down the cloth or the
neoprene layer?  Or is my desire to find such a chemical just a 'pipe
dream'?   (And where did that phrase ever come from?  Is it a
throw-back to the opium den days?  Shades of Ching-Chong Man!!)

John A. Tuttle

Key Words in Subject:  Bellows, Cloth, Rejuvenating

Home    Archives    Calendar    Gallery    Store    Links    Info   

Enter text below to search the MMD Website with Google

CONTACT FORM: Click HERE to write to the editor, or to post a message about Mechanical Musical Instruments to the MMD

Unless otherwise noted, all opinions are those of the individual authors and may not represent those of the editors. Compilation copyright 1995-2024 by Jody Kravitz.

Please read our Republication Policy before copying information from or creating links to this web site.

Click HERE to contact the webmaster regarding problems with the website.

Please support publication of the MMD by donating online

Please Support Publication of the MMD with your Generous Donation

Pay via PayPal

No PayPal account required

Translate This Page