[pianotech] Pumper Flap Valve Leather

[John Ross]

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