"RST Engineering" wrote in message
m...
Clothes dryer ducting.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"Stuart & Kathryn Fields" wrote in message
...
I'm looking for a source of 1 1/2" flexible exhaust tubing. Mild steel
is acceptable. I want to use it for a model of the headers of a tuned
exhaust for my 0320 Lycoming engine that I have mounted in my Baby Belle
helicopter. The idea is to have 4 equal length pieces attached to exhaust
flanges bolted to the cylinders, arrange the 4 pieces to intercept the
4-into-1 collector, coat the tubing with epoxy resin so that the shape is
maintained and then present these pieces to be copied by the exhaust
bender.

Stu

To date I've tried flex conduit, both steel and aluminum and both sag like
crazy and change lengths easily and don't hold their shape. Heating and
bending PVC pipe is such a cut-and-try process which also produces some
fumes off the PVC that is not supposed to be nice and the use of elbows and
saw cuts is kind of workable and I have a set of 4 equal length pieces that
have been shaped to do the job but the thing looks like crap and the exhaust
is really open for view on this helicopter. Hopefully the flex exhaust
tubing will hold its shape when bent by hand long enough for me to coat it
with epoxy to lock in the shape and hold it for a trip to the exhaust tube
bender guy.
The trick that I'm counting on, and it looked possible when I was using
conduit, is to connect the tubing to exhaust flanges bolted to the cylinders
and position all 4 pieces to intercept the 4-into-1 collector at
approximately the same time and counting on the flex tubing to hold its
shape and length, long enough for some epoxy to sieze the flexables even
further. The idea then is to remove each piece and have it matched.
I've tried AutoZone, Pep Boys, Napa, and JC Whitney. McMaster-Carr, Toys 4
Trucks, Whitney does have some SS flex but at $30 each 5' piece. This would
run the cost up a bit. I hope to finde some galvanized steel flex somewhere
at a lower price.
Stu