[pianotech] Pumper Flap Valve Leather

[Ron Nossaman]

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