Perflex, the long sad story, and other modern substances
This is the story of Perflex as I saw it. During the Vietnam War our
government researchers came up with a substance that they could make
large bags out of. These bags were to carry water to the troops. The
bags they came up with could be rolled out of helicopters and hit the
ground without puncturing. The substance they used was called Perflex.
When the war was over, someone decided to use the leftover Perflex on
player piano and pipe organ pouches. It worked very well. The only
problem was gluing it down. No glues would hold it down -- it would
walk right off the glue. Then they found PVC-E glue and it worked
better than others. It still tried to creep off the glue.
Durrell Armstrong solved the problem by bonding the Perflex to a paper
ring. Durrell told us in the early 1970s that we would not be able to
get pouch leather or other leather in the future so we had to go to
this Perflex product, since it is stronger, lasts longer and will never
deteriorate like leather does in thirty years. He also said we would
have to go to sponge neoprene and Polylon.
The problem: When the original batch of leftover Perflex was used up,
they went to the chemical company to have another batch made. This
batch was inferior. For some reason there was something missing or
added to the recipe. This new batch did not last like the original
batch did. This is why you may find a player piano or pipe organ with
Perflex on it that is still going strong. It was done in that original
batch of product.
I never got any of that, but I have run into it recently in organs.
The Perflex I used on my own piano for testing lasted six years before
crescent shaped cracks appeared in the pouches.
The Austin organ company built a new organ for Highland Park Methodist
next to the SMU campus in Dallas. Within 6 months they were having
problems with the all Perflex covered chest system. A year or so later,
the very high powered lawyers in the church made Austin an offer they
could not refuse. They pulled out the organ and recovered everything
with leather removing all Perflex from the chests.
It would not have been much of a problem except the organ is something
close to 140 ranks if memory serves me. That means they had to shut
down production of other instruments for months just to rebuild
something that large. I do not know if that project caused business
problems for them but it could not have been good for the company.
I never used any Perflex on anyone's piano, but I did experiment with
it and all Durrell's (PPCo's) new products on my own Duo-Art. I put
Perflex on the pouches, sponge neoprene on the valves, and Perflex on
the pneumatics. The result was the Perflex on the pneumatics popped
like balloons when the Duo Art hit the crash valve.
The Perflex crept off several pneumatics. I replaced the Perflex on
the pneumatics with blue Polylon. This worked fairly well, but it
crept off the pneumatic boards as well.
The sponge neoprene valves worked for a while but within months,
you had to crank pressure up to full tilt before each roll. I would
stop the roll at the beginning, crank up the theme volume and hit the
snakebite levers. I could then listen to the stack pressurize. The
roll would then play very well.
I later replaced the valves with a rougher leather than I would have
preferred. I also found I had to replace the Polylon on the pneumatics
again with standard pneumatic cloth. Valves and pneumatics was a quick
job done in less than one week since a theater group was needing to
use the Duo Art in a month of performances. I was not happy with the
leather but it worked okay.
Ten years later, I found that the pneumatic cloth had gotten stiff
and was flaking off. I recovered them again with Australian pneumatic
cloth. I also replaced the valve leather with precut valve facings
from Durrell (PPCo) I got the stack together and found bad seepage.
I did not know the leather from Durrell was porous and inferior, so
I ordered round valve seats to replace my cross valve seats. That did
not solve the seepage problem.
I was always accustomed to closing all pouch nipples and sucking on
the main supply to one side by mouth, When a Duo-Art stack is in good
shape there will be no seepage more than perhaps a pinhole of air
passage. I could not get that for anything even with the new seats.
The piano never played as well as it did with the rough leather, so
recently I have been replacing Durrell's leather with some great leather
I found last year. It is fully airtight. I have also reinstalled the
old cross valve seats that belonged there. I have not had time to
complete it but I hope to this year.
I am extremely glad I did not use these products on my customers
pianos. I do not have to do warranty work, and we warranty everything
for five years. It is work keeping up on the quality of your supplies.
It is worth it though. I am sorry to those customers who's pianos
I used PPCo bellows cloth on through the 80's since the cloth has most
likely failed by now. My own pianos had it fail and I have lost touch
with the customers so I cannot contact them now to find out.
I am now much smarter after the 30 years I have spent rebuilding my
Duo-Art. All that work accomplished only one thing. I know better
than to use ANY new product that has not been tested for 30 years or
more. You may call me a stick in the mud if you like but I know when
I rebuild a player system, it will last 30-50 years. I know I have
done everything possible to make sure of that. Yes I have restored
many other Duo-Arts in that time but they were all done with traditional
D.L. Bullock - Piano World
2732 Cherokee, Saint Louis MO 63118