[pianotech] Pumper Flap Valve Leather

[Stephen Grattan]

Euphonious, 

IMHO nylon webbing would not be suitable as it needs to some ability to stretch and be flexible.  Leather, properly prepared, has lasted over 100 years in some old organs.  Another hundred and it will be someone else's concern! <G>
 
Steve Grattan
Lost Chord Clinic




________________________________
From: Euphonious Thumpe <lclgcnp at yahoo.com>
To: pianotech at ptg.org
Sent: Friday, June 5, 2009 11:53:44 AM
Subject: Re: [pianotech] Pumper Flap Valve Leather


Though this will make the "traditionalists" squirm, I can not but help believe that SOME modern material would be better for bellows flap valves 
( like nylon webbing with an air-tight facing? ) for this very reason. And also for longevity and uniformity......
Euphonious Thumpe


--- On Thu, 6/4/09, John Ross <jrpiano at win.eastlink.ca> wrote:

> From: John Ross <jrpiano at win.eastlink.ca>
> Subject: Re: [pianotech] Pumper Flap Valve Leather
> To: pianotech at ptg.org
> Date: Thursday, June 4, 2009, 1:21 PM
> The originals, which will be
> replaced, have a  piece of wood attached to one 
> end, and a piece of wire attached and bent to put pressure
> on the flap.
> I have seen some with a coil spring attached to each
> corner.  Most, if not 
> all of the 4 spring type had a tin section over the flap.
> Good point about the stretch  being one way.
> Thanks, as always to the list.
> Sorry I won't be seeing any of you at the convention this
> year, but the Las 
> Vegas venue for next year, sounds like another reason for a
> drive out.
> John Ross
> Windsor, Nova Scotia
> ----- Original Message ----- 
> From: "Ron Nossaman" <rnossaman at cox.net>
> To: <al at pebworths.com>;
> <pianotech at ptg.org>
> Sent: Thursday, June 04, 2009 1:47 PM
> Subject: Re: [pianotech] Pumper Flap Valve Leather
> 
> 
> Al Pebworth wrote:
> > Hi John,
> >
> > I recently restored a Mason & Hamlin Reed Organ,
> and installed new flap
> > valve leather.  I got a big surprise!  Organ
> lost vacuum, I went on a
> > 100 mile service call, found that all of the flap
> valves had expanded,
> > about 1/4 inch in length, so would not seal.
> >
> > As the inside valves were also not sealing, I had to
> bring it back into
> > the shop to fix.  Now I have lost a lot of
> profit!!  I did notice that
> > this leather was a bit thicker than what I had used in
> the past.  I know
> > that the flaps were tight when I put the in. 
> I'll put springs on them
> > this time, or use a thinner leather with blued spring
> steel over it,
> > like is found in a Seeburg Coin Piano, and some other
> players.
> >
> > Al
> 
> John, Al,
> Leather, you likely already know, will stretch more in one
> direction than in another. I've always cut organ flap
> valves
> so the stretch is minimal along the length of the strip.
> The
> valves will "cup" some across their width, but don't get
> longer and go slack. Of course, now that I've said that...
> 
> Springs are very good cheap insurance too.
> Ron N
> 
> 
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