I have been reading about how we cannot glue Polylon with hot hide
glue. Since I have been doing this now for 18 years whenever I happen
to use it, I can tell any who are interested the basic principle to
this -- or to any other thing they may want to know if it glues or not.
I realize this sounds so obvious I needn't even say it (again), but as
I have been reading these stories about the disasters of Polylon, and
what works and doesn't work, not one person has yet come up with the
wise thing to do. I guess you can sum it up by saying, "Let's stop
jumping to conclusions and check some things out, first."
I don't rebuild with any other kind of glue, generally. If I can't
use animal glue, I would quit. So you can be sure that whatever kind
of cloth I choose, it will either be a perfect bond and long-lasting,
or I wouldn't use it.
In my book, The Orchestrion Builder's Manual and Pneumatics Handbook,
on page 188 is a signed letter from the man still responsible for
Milligan and Higgins' hide glue. (At that time it was Hudson.) He
warrants the bond to be perfect. So I published Jacob Utzig's letter
certifying the fact!
As far as Polylon's peeling is concerned -- that was fixed 20 years
ago, but a few rebuilders don't bother to check these things out to see
if things have changed before they write. This tends to steer others
wrong, simply because 10-15 years later, they may have had to replace
a set of pneumatics.
The adhesion problems in some batches of Polylon was just as disaster-
ous with plastic glue as it was with hide glue because some of it had
a mold release coating that refused to be glued by anything. I had a
set of pneumatics which literally slipped out of their covers in about
six months. These are some of the problems you run into when you take
things for granted and don't test properly, first. I should have
tested it better, and then tried wiping down some with lacquer thinner
and gluing that too, to see if it was stronger. That would tell me if
there was a coating, or not.
The coatings were put on the poly sealant whenever it was felt that
the sealant wasn't cured well and would stick together in the bolt!
So, if you run into that stuff, don't assume it's _all_ junk. And
don't buy in huge quantities until you are happy with the results of
your own checks.
As far as wear and tear is concerned, I was visiting Art Reblitz one
time about 1981, and we were listening to a large, commercial-duty
orchestrion (great job, by the way) that he had built for a pizza
parlor using Polylon. After over 100,000 plays by the coin counter,
its pneumatics were still as tight as when they were new.
He said he could see a white line running around them and also what
looked like tiny pinholes in the corners, and figured they were worn,
but when tested, they tested perfectly tight. He also said that cotton
and rubber cloth would have been worn out in half that amount of time.
I agreed, since I too realize that cotton/rubber cloth wears, and
50,000 plays is about all you're going to get.
I have had the old blue Polylon from American Piano Supply Co. in my
Ampico B since 1981. It gets played constantly, and it's in as good
shape as the day I put it in. I buy the dark maroon now from APSCO.
It is this that Jacob Utzig certified for me as a good bond. I have
learned to tell if a batch has a properly cured poly coating on it,
even before I use it, and then I check out adhesion.
If you want to check adhesion, cover a half-dozen test pneumatics with
the poly side in. Let fully dry, and insert an air gun nozzle with a
rubber cork into the feed hole. Set the air for about 26 psi, and
blast. If the cover pops, you didn't get a good bond. I bet that few
if any cotton/rubber covers will meet this test unless they are ironed
down. But all my Polylon covers will meet it, or they get re-glued, and
We all could keep materials that were formulated wrong or didn't work
well as proof never to try any more of that again. But that just isn't
the way to know. What the company did in one batch does not assure you
of great batches of it again, for the rest of your lifetime! Test it
From now on, I'd like to see rebuilders speak a bit more circumspectly
about these so-called materials "that aren't any good," and consider
the idea to test first, before making absolute statements as to whether
this or that material is no good! This kind of information doesn't help
anybody, and really misleads the novice -- particularly in the light of
hundreds of other rebuilders and weekenders who are having great suc-
cess with it. And, use hot hide glue -- poly side in. You'll love it!
[ Editor's note:
[ Don't overlook Craig's observation, "What the company did in one
[ batch does not assure you of great batches of it again." These
[ corollaries come to mind:
[ 1. Without thorough testing by the manufacturer and dealers, there
[ are likely to be _many_ pieces of bad Polylon still circulating
[ among the suppliers and the rebuilders. No wonder Polylon has
[ a bad reputation.
[ 2. If you want to buy pneumatic cloth which is identical to the
[ cloth used successfully by Craig and Art Reblitz, you must get
[ cloth that exactly matches the critical properties. If you're
[ lucky the supplier's records will show the production number of
[ the material Craig and Art purchased.
[ 3. Test it thoroughly!
[ -- Robbie