[pianotech] Pumper Flap Valve Leather

[Ron Nossaman]

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