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piping a gas kiln - bending pipes

updated sat 20 jan 07


pdp1@EARTHLINK.NET on fri 19 jan 07

Hi Dan,

...if one fill the length of Copper Pipe with dry
Sand, pack it in there snug, and then gently bend
it around something like a 55 Gallon drum side, or
whatever of a round aspect of about the right
diamater, or by hand, over one's knee-cap dent,
bending a little here and there till the desired
curve is attained, there will be no kinks.

1/2 inch or 3/4 inch Copper would be best if long
enough to have some leverage, and to work the bend
gradually, almost imperceptable, on something
rounded for a fulcrum of sorts, if ones thumbs or
knee protested.

Some people can do this cold, and with no Sand
too, if patient.

I used to run ( albeit, smaller diameter, but the
principle is the same, ) Steel Brake or Fuel lines
fairly often on various Cars or Trucks I was hired
to work on, and I always did it this way, in my
hands, nothing in the lines, working it just 'so'
to get the various odd bends and straight runs and
roundish 90s and so on with no kinks.

But yes, if you inadvertantly concentrate the
bending force too much 'in' one place, it will
kink. Or some inferior products may, likely, even
with careful manipulation.

One can use Heat to gently Work Steel Pipe into
various fine curves, and it is fun to do. I do not
remember if this works as well with Black 'Iron'
Pipe but it might. Probably one could do likewise
with Copper but I never tried it. Of course one
can also do this with the various PVC Pipes, if
differently technique-wise, and if with a lesser
heat of course, so long as one practice a little
to get the knack and not scortch them too much.
They just get limp ( like boiled Spaghetti ) and
one set them how one wants them and as they cool
they go back to their old rigid selves again.

I just did a couple the other day, Mirror Hangers
for an old Truck, made a deep bend in a one foot
length of 3/4 inch OD Steel Pipe or Tubeing,
prolly 3/32nds wall, working it with Heat
localized in one spot and gradually moveing the
heat as I kept a bending force on it, actually
working it with heat on the foreside and the
backside alternately, for it to compress and
respectively stretch to make the bend nicely and
stay nice and as I progressed along its
length, I got the curve I wanted, about like a
half Circle, with only a little finessing needed
after. This was some sturdy Tubeing too, much more
than a man could bend cold by hand...or maybe a
really strong person could bend it badly in their
hands, but they'd kink it if they did.

I just had one end of it in a Bench Vise, and one
end I gripped with some stout Pliers. Heat was via
an old Oxy-Acetylene "Purox" outfit, but a small
size tip...then flipped it over and continued, so
as to get the 'ends' being part of the arc...

I am sure one could do Copper this way too, useing
a Torch and having the heat on the frontside and
backside in close turns as one carefully keep the
bend progressively advanceing as one goes
along...and did not get it 'too' hot of course.

el vee

----- Original Message -----
From: "Dan Saultman"

> Soft copper piping at the diameter needed for a
gas kiln is not soft at
> all. It will fold or kink on you. Even using a
large pipe bender isn't
> easy with this stuff. I went to my gas company
and had them make a
> length of their special plastic pipe. If you go
this route, it should
> have the appropriate fittings fused to each end.
It bends around
> curves, is light weight and better than copper
in my view. I had a
> friend try copper and had a real tough time
making bends and curves.
> Dan Saultman
> Detroit