Hello All!  Some comments on MMD I just can't help not responding
to being a restorer of mechanical music machines.  So I'll say again,
I do not recommend sealing pouches with any type of rubber cement!
Or anything else, for that matter.  Before it's mentioned, I understand
that there are a couple of instruments that originally used this
practice.  That does not mean the same method should be carried on to
the other 99% of the instruments.

As I have most likely mentioned in the past, and being that I'm
seeing an increase of this particular issue being one of the main
causes of mechanical machines to drop notes and in some cases deem them
unplayable in colder climates in which the leading excuse that I hear
is that (the wood is expanding due to the climate), I do not agree.

It's no secret that rubber hardens when cold.  Additionally, there are
many manufactures of rubber cement that have different characteristics.
For example, some would sink into the material more and some harden
more when cold, to just name a few.

When restoring instruments, I always approach things from a mechanical
standpoint.  What is the purpose of this particular part and how does
it work efficiently.  Everything has to make sense and work together
like it was originally designed to do.  Pouches are chosen for their
flexibility and sealing ability but in most cases don't need to be 100%
air tight to achieve maximum performance by design.  By introducing an
unknown substance coating and sinking into the pouch, mechanically you
are taking away one of the main mechanical duties that the pouch was
designed to do.

To date, other than tuning being affected, which is normal, I have
never had a complaint from an instrument that I restored not operating
correctly or skipping noted in colder climates, for example, band
organs played outside.  In my opinion, this mainly happens due to
sealing pouches and or in conjunction with inadequate valve travel.

In conclusion, the fact is there is no way to control how much rubber
cement is installed on a pouch nor how much is absorbed by the leather
in which can be inconsistent due to the type of leather and can differ
one to another.  This only takes away the pouches ability to flex which
is more important than its ability to seal.

There is just simply no need to result to sealing pouches when there
are acceptable materials to use, such as Morton's pouch leather (maroon)
from Columbia Leather Supply, or possibly using when applicable
silk-backed pneumatic cloth which is .006" thick available from the
Leather Supply House.

Remember, the instruments will always reward you with years of
entertainment when the correct materials and restoration practices are
used.

Happy restoring!

Robert Loeffler
http://www.robertsmusicalrestorations.com/