I would like to add the following information to Craig Brougher's
informative article in Digest 970522 regarding cloth and glues.

Having restored automatic instruments since 1966; in the literally
hundreds of untouched player actions I have dismantled, I have carefully
observed which adhesives were used in each.  When pneumatics were covered
with fish glue, the cloth strips off cleanly and does not tear to shreds,
as it often does when hot hide, bone or hoof glue was used.  Aeolian used
fish glue for covering inspection slots in valve rails, as the fish smell
clearly indicates when these are removed; and I would like to know
whether anyone has ever seen "soggy" glue under these.

I likewise have never seen a single case of softened glue under pneumatic
cloth covered using fish glue, and lived most of my life in the Midwest.
Pneumatics covered using this which are still supple, are 100% airtight.

It is logical to think that an highly water-soluble glue, such as fish
glue, would soften in humid weather.  Practical experience shows this not
to be the case.  I would assume that this is because most of the glue is
not exposed to the air.  Animal hide glue is also water soluble, though
not so much as fish glue; and after 150 years of humid weather it often
easily supports the 75,000 pounds of tension in a piano, nor does the
sound board usually return to its component planks, unless it sits for
years in a damp basement or out on the porch.  (This has, also, to do
with the quality of glue, and gluing techniques, used by the
manufacturer.)

Craig's idea may stem from the types of fish glue he has tested.  When
working at San Sylmar in 1979, I first tried fish glue.  It was sold
under the Mohawk name, and manufactured by the venerable parent company
Behlen Bros. in Amsterdam, New York.

While highly suitable for leather, this glue was, indeed, similar to the
LePage product, and quite useless for any kind of cloth.  Perhaps this is
similar to what Organ Supply Co. sells.

I don't recall how I discovered Norland High-Tack Fish Glue, made by the
largest manufacturer of this glue in the U. S., but this is nothing like
LePage glue.  It is tan colored, creamy and tacky, should not be
ingested, and sets very fast.  I sent samples to Art Reblitz and Hayes
McClaren, both of whom were highly impressed and had good results with
it.  Craig should be receiving his sample soon, and he can then test it
and report to us.  Norland also offers a viscous, honey-consistency,
food-grade version of the same, which is also excellent.

I was an early researcher in the use of hot animal glues, and inspired an
article in Fine Woodworking some years back about the late Peter Cooper
Glue Company, the oldest company in the U.S. and the largest maker of
animal glues in the world, before they closed a few years ago.  Now the
best source of animal glue is the Hudson Glue Company, subsidiary of
Milligan and Higgins.  I have tested every grade of animal glue, of which
there are many, and am acquainted with the best ones for player work; of
which, unfortunately, those grades available from our friendly vendors
are usually not.

It is important to emphasize that hot animal hide glue is the only
suitable glue for every grade of motor and bellows cloth.  Fish glue from
Norland is only usable for cotton-backed or silk-backed pneumatic cloth
thinner than .008."

Fish glue is far superior to any hot or cold hide or other glue for the
gluing of leather.  There is no comparison.  When properly glued with
good fish glue, most leather would have to be torn to shreds to be
removed, in any weather I have ever experienced.  If the leather is
strong, you would have to split it edgewise.

Larry Broadmoore