Regarding the recent claims that rubber cement was never used on
pouch leather, here's the original reference from page 17 of the
Ampico Reproducing Piano 1919 Inspectors' Instruction Book:

  "How to Rubberize a Pouch."  The rubber cement used should be kept in
a small bottle and be just a little thicker in consistency than water.
Rubber cement such as sold by automobile supply houses and used for
cementing patches to tubes is all right if it is thinned with naptha
[sic] (not commercial gasoline).  "Anchor Brand" rubber cement sold by
the Woolworth 5c and 10c Stores does not need thinning.

  "Apply the cement with a small brush while sucking vigorously on the
pouch with a suck tube so as to draw the cement into the pores of the
leather.  Let the first coat dry and apply a second, but not without
sucking on the pouch.

  "Apply as many coats as necessary to make the pouch tight.

  "Paint the cement on neatly and cover only the portion of the pouch
that is drawn down by the sucking.  Do not get any cement on the
outside rim of the ouch where it is glued down.

  "Apply talcum powder to pouch after last coat of cement is dry.  This
is necessary and will keep the surface of the pouch from being sticky.

  "Clean the brush with gasoline immediately after using as it does not
clean easily after drying." [End of quote from Ampico Inspectors'
Instruction Book]

Comments:

1. It is imperative to keep the rubber cement thin and to suck it
into the pores of the leather, per the above instructions.  If the
consistency is too thick, or if too thick a layer is applied, the pouch
will become stiff.  This is especially critical in pouches smaller than
1 inch that work on low vacuum in a reproducing piano.

2. Use a test pump or other vacuum source, not your lungs, to suck the
thin rubber cement into the pores of the leather.  You do not want to
force naphtha into your lungs!

3. Use naphtha in a well-ventilated area to clean the brush, not
gasoline!

In my shop, we primarily use traditional techniques and materials,
including hot glue, shellac, and of all things, rubber cement thinned
with naphtha on pouches -- where it's appropriate.  Readers who condemn
the use of these materials might want to examine instruments that we
and other "traditional" restorers have restored for collections open
for occasional MBSI and AMICA meetings.  We are happy to let our
lifetime of work speak for itself.

Art Reblitz