having just tried and failed to sand-bend 1.5" 16Ga. steel tubing, I'd say
that you may need to go to a specialist shop to get this done. But I have
two ideas. One idea is to fill the tubes with molten lead, let cool, do the
bends at a muffler shop, then heat and remove the lead, which you can do
with an acetelene torch. The lead will minimise the distortion. I've seen
header systems done like this, and they looked good. The second idea, which
is what I'm doing to build my header, is buy some mandrel bends - which come
in different sizes, and radius bends, and cut and butt weld the bends in the
configuration that you need. This is how most prototype headers, including
Champ car and F-1, and actually made, if you examine them closely.
At 07:00 PM 1/28/98 -0500, you wrote:
>I'm looking for some help with bending tubing. I'm trying to make something
>which will require some sharp successive 90 degree bends in tubing.
>I will be using some tubing ~1-1.5" o.d. (undecided) 1/16"-1/8" thick.
>The two 90 degree bends will be about 3" apart, and perpendicular to each
>other. I would also distort the tubing as little as possible.
>I understand a mandrel bender would be the best route, but I don't happen
>to have one in my garage... The only thing I can think of doing is to
>clamp down two pieces of heavy rod in my vise, heat the tubing to cherry-red
>with an oxy-act torch, and then bend it using the rod. But I think this
>will seriously distort the tubing.
>Can anyone recommend a better way to accomplish this?