Goatboy on glues, or "What happens to old Centaurs?"
(They become glue of the Gods.)

As a rebuilder and Amish-trained cabinet maker I have a few opinions on
glues.  I very happy to see the posts by Mr. Bullock and Mr. Brougher,
giving directions on how to use hot glue.  When I first started out
rebuilding players in my early teens I used hot glue exclusively, but
I had my pot temperature setting too high and I didn't quite know how
to use it.

The glue didn't set correctly and would flake and break off the
surfaces.  After 25 years I still have to pick a tiny glue drip out of
the valves of my Weber player every 8 months or so.  Once I learned the
proper mix and temperature I began using it again on a limited basis.

When I began working as a cabinet maker I was exposed to a variety of
glues, some of a very exotic nature, all of which have very specific
applications.  I would have to agree with the other cabinet makers:
hot glue just don't cut it at all.  A piece of furniture in ancient
Egypt wouldn't last a year in a Midwest American basement; seasonal
shrinking and swelling of wood in this climate challenges the
properties of most glues.

I have just finished making a whole new cabinet for a Wurlitzer 153
band organ case.  (I will be posting the details in my web site in a
few days).  My glues of choice were yellow casein glue for the joints
and urea-formaldehyde for the veneering.  I don't use the latter glue
in player rebuilding at all, but for any kind if veneer work or repair,
it's great.  I also use it for fabricating hardwood core plywood for
replacing boards in pumps and reservoirs.

The down side of urea-formaldehyde is that it is very toxic in it's
powdered and liquid state.  (The lid says: "Contains a substance known
to cause cancer in the state of California..."  Well, I don't live in
California).

Once dried it has many characteristics of hot glue.  It dries rigid
and can be easily shaped and sanded.  The differences: very slow setup
time, up to 20 minutes, which is very good when you are working with
large sheets of veneer, and secondly, it is totally resistant to water,
solvents and heat.

I've read a lot of negative comments about casein glue and I would
agree that white casein glue is not very suitable for use in
restoration.  Whenever a previously restored player comes into my
shop where that Bilon cloth is glued on with good ol' PPCo #620 glue
-- it's time to make a whole new set of pneumatics.  However, I have
found yellow casein (Woodworkers) glue to have many useful applications.
The basic concern is being able to sand the old glue off neatly in the
next go-round.

I discovered that when using an iron set at a bit above boiling, yellow
glue will crystallize and will sand off a wood surface in the same
manner.  It is the principle method I use in gluing rubberized cloths.
Now, for bonding leather, hide glue can't be beat.  After all, they
both come from the same source.

I always assumed that hot hide glue was all the same.  Last week,
I was visiting a commune that was hosting a theater troupe.  One of its
members made all kinds of elaborate masks.  I went past his van where
he had a little studio set up; I had to take a peek.  On his work table
were some jars of hide glue separated by the species.  Rabbit, pig
and *goat* were the ones I could read.  I was really wondering, "What
are their properties that makes them different from run-of-the-mill
hide glue?"  Unfortunately, I was never able to talk to the guy and
find out.  Isn't that a new can of worms?

I hope I didn't put a lid on my coffin by stating I use yellow glue.
Almost every other player that comes into my shop now has been
previously *rebuilt*, and I have to say that I have seen as many
botch jobs done with hot hide glue as with any other.  For instance,
a Pratt-Read pump covered in Naugahyde held on with 94 ornamental
upholstery tacks and very liberal amounts of hot hide glue.  We just
took the hardware off this one and made a new pump.

But I think the glue that gets the prize for no redeeming value is
the white hot melt glue that comes out of the guns.

Brian Thornton, Short Mountain Music Works
http://www.mindspring.com/~goatboy/smmw.htm