On Sat, 08 Aug 2009 10:05:28 -0500, brian whatcott
wrote:

Stealth Pilot wrote:

I'm convinced that finishes like razorback and ceconite over polyester
would not be certified with the hindsight to see their faults.

my aircraft was covered in Stits, or Polyfiber as it is now know, back
in 1983~4. despite thinking that it was good for maybe another 4 years
for all of the past 10 or 12 years the bloody stuff just will not die.
it is painted in polytone which will remain repairable for the life of
the finish. just wipe back with a rag soaked in MEK, do the repair and
rebuild the finish. /snip/
Stealth Pilot

Is polyfiber a proprietary name for polyester 1.8 ounce heat shrinkable
cloth - also found in drapers as polyester lining material?


Brian W

no. and the difference is a very important one.
when polyester fabric is woven the yarn is first stretched slightly at
an elevated temperature. after weaving the cloth is passed through
another heat process to cause the yarn to shrink and better bed in
with the weave. it makes a better fabric for your dresses.

polyfiber grabs the woven cloth before the second heat process.
it is called the greiged state.
after you glue the fabric to the aircraft structure you go over it
with an iron. the ironing causes the fabric to shrink as per the post
weave process for dress fabric. it is that shrink that taughtens up
the fabric, something done by the dope when a natural fiber is used.

so if you buy store dress material you will not in theory have any
method of taughtening it other than to use dope.
if you can buy the drapers polyester lining material in the greiged
state then theoretically it would be usable.

Stealth Pilot