Hide glue is a wonderful glue.  A question a week or so ago went
unanswered and I think I may be of some help.  I use hide glue for
everything.  It is probably because I am used to using it and second
that the other glues seem to just go bad on my shelf from lack of use.

When using hide glue on pneumatic cloth it is  sometimes a problem
getting cloth to stick well to the boards.  I make sure the boards are
clean and then I try to warm the boards with an iron so the glue does
not have time to set in the winter time.

I will sometimes use an old iron to "iron the cloth" to adhere to the
board.  If there is any silicon present then no glue will hold.
Certain types of cloth sold for player repair is a nylon type of cloth
that does not adhere well.  I would not use this cloth.

Currently I have a player in the shop that was beautifully restored
several years ago by someone that used the synthetic type of cloth.
This cloth is hard as a rock while the striker pneumatics, which were
covered with old fashioned cotton cloth with rubber coating, are still
soft and airtight.  Others have reported how well their synthetic cloth
has held up when the cotton cloth has failed them, so you be the judge.
It is almost like playing a dice game.

When covering pumps with the heavy cloth it is best to coat the boards
with a light coat of glue and the apply a second coat as you cover them
with the cloth.  I always iron this cloth into place for a good glue
joint.

Hide glue will survive the coldest winters and hottest summer months
without letting loose.  Just look at those old band organs and notice
that they have really been through the toughest temperature conditions.
Hide glue is still holding them together.

Learning how to mix the right amount of glue with water may be the
hardest part.  I am asked often how I mix it.  I start with about an
inch of glue in the bottom of the pot and add water to cover it.  Let
it soak in the glue pot for the night with the heat off and then the
next day with the heat on in the pot.  Wait about ten minutes.  Now I
add water until I have the thickness I need for whatever I am gluing,
thick heavy glue for veneer work and thinned glue for cloth-to-bellows.

Thick is about like maple syrup and thin is thicker than water.  Put
a dab on your fingers and hold them together for a second or two if you
want to test.  It is a great glue once you learn how to use it and
about the only glue you will need in the shop.  I just re-veneered
another piano with hide glue.

About once a year an article appears in a woodworking magazine telling
the virtues of hide glue and how wonderful it is for veneer work.  The
contact cements made for veneer are just about guaranteed to let loose
when used on a piano.  The swelling of the woods in a piano will weaken
the cement bond quickly while the hide glue bonds seem to hold much
longer.  Try it.  You will like it once you learn how to mix it and use
it.  I also must mention that Craig Brougher has recently written an
excellent article on hide glue and other glues on the Player Care site.

Speaking of articles I am also under the impression that soon there
will be a new set of technical articles on how to make Wurlitzer valves
coming to the MMD site.  I guess there is a spot on the MMD for technical
material.

Don Teach