Robbie, I apologise to you and the group for returning to a subject
that has probably been discussed ad nauseam, and if you consider that
the answers to my query lie somewhere in the Archives then please tell
me so and I will spend a couple of hours interrogating them.  My main
reason for raising these points in the forum is to resolve doubts that
I have, fearing that others may have them too.

 [ Thanks for writing, Roger; it's a good topic.  -- Robbie ]

I am concerned that I may be wrongly interpreting critical information
regarding the application of valve leather, and would appreciate advice
from the group as to correct practice.

I am referring specifically to lower valve facings sealing on to metal
seats, typically Standard wobbly valves using fibre disks threaded on
to wire stems.  Best opinion seems to favour thin calf skin as the most
suitable leather for this purpose, and that is what I therefore use --
very smooth (matt, or even slightly shiny) on one side, having no
nap, and smooth suede on the other, having a soft, fine nap.

My question is this:  Which side is glued to the disk?  My reason for
asking is based upon the following apparent conflicts in published
text.  I say 'apparent' -- please tell me if I am deficient in my
reading skills.  :-)

Source 1: "Player Piano Servicing and Rebuilding" by Arthur Reblitz,
page 87 para. 1.  Quote: "Never attempt to glue the shiny side of
finished leather to anything; sooner or later it *will* come loose".
This suggests that the nap side is glued.

Source 2: "Rebuilding the Duo-Art" by Michael Kitner, page 11 para. 3.
Quote: "Reinstall the valves, pressing them against the lower
seat and giving them a twist in one direction to flatten out the
nap of the leather."   This suggests that the smooth side is glued.

Source 3:  Experience.  I seem to have come across examples of both.
A lot of Standard type valves seem to me to have been glued on the
smooth side with the nap uppermost, whereas some smaller type valves
seem to have been glued with the smooth side uppermost.

Now, am I not understanding the term "finished leather" properly,
or am I just a poor reader?  Does practice vary from instrument to
instrument?  What are the performance implications of gluing the
"wrong" side?  All comments welcome.

Roger Waring