[pianotech] Pumper Flap Valve Leather

[John Ross]

Thanks Al,
This stuff is thicker. Sounds like a prestretch is in order.
John Ross
Windsor, Nova Scotia
  ----- Original Message ----- 
  From: Al Pebworth 
  To: pianotech at ptg.org 
  Sent: Thursday, June 04, 2009 10:24 AM
  Subject: Re: [pianotech] Pumper Flap Valve Leather


        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

        Al Pebworth
        Chesapeake, Va
        http://www.pebworths.com

        --- On Wed, 6/3/09, 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: Wednesday, June 3, 2009, 10:43 PM


          Hi Ron,
          This is one I started a while back.
          The wood had all delaminated, so I got some 5/8" birch plywood and  copied 
          the old one. So it is all new hinges, etc.
          The previous leather flaps I used,  were the precut ones, and they were a 
          firmer thinner,  more refined type.
          I had purchased the bulk a while back, and noticed there was quite a 
          difference in texture.
          It is the laying flat and being air tight that I was concerned about.
          I will try the sanding and see what happens.
          I suppose it might even have been all right as was, after all it was sold, 
          as flap valve stock.
          John Ross
          Windsor, Nova Scotia.
          ----- Original Message ----- 
          From: "Ron Nossaman" <rnossaman at cox.net>
          To: <pianotech at ptg.org>
          Sent: Wednesday, June 03, 2009 11:17 PM
          Subject: Re: [pianotech] Pumper Flap Valve Leather


          John Ross wrote:
          > *I purchased some bulk flap valve leather. *
          > *Previously, I had used the precut individual ones.*
          > *This leather has courser hairs, or whatever the strandy stuff is.*
          > *I was thinking that this wouldn't be as air tight, so I was thinking on
          > putting it hairy side up, on a flat surface and sanding it.*
          > *Would this work, or should I just go back to ordering individual ones
          > from Schaff? *
          > *Or just cut it to size and use as is?*
          > *I can't even remember where I got it, probably APSCO.*
          > *I suppose I could just use the original inside ones, as they seem fine. *
          > *That way if the outside ones didn't work, I could just change them,
          > without having to recover the bellows?*
          > *Any suggestions most welcome.*
          > *Thank you.*
          > *John Ross*
          > *Windsor, Nova Scotia, Canada*

          John,
          Sanding will do it. Try different grits and materials until
          you find something that is sharp enough to cut the stuff.
          Going over it with a very sharp Red Devil type scraper
          (shearing cut) might be a beneficial first pass. It depends on
          the leather. Sanding afterward doesn't actually remove the
          woolyboogars. but it will shred them enough so they'll lay
          down and pack in to a fairly smooth and airtight surface.

          While I've left a couple of sets of interior flap valves in
          30+ years, when I'd determined by abuse that I couldn't
          replace them with anything better new, I've always re-hinged
          and recovered pumpers. I've seen too many instances where
          someone else didn't, and it proved to be the wrong call.

          Ron N


       
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