Need ideas on how to bend 4" tube

[sgt_rock]

I'm working on a rat solution to the intake silencer - or whatever that big black plastic air flow obstruction device is call.

I have a 4" 90* elbow that I need to bend in about 10 more degrees. I haven't found anyone locally that can bend that large of a tube, so I need to get creative.

The only option I've come up with so far is to heat the bend. I'll need two torches and second set of hands to try this one. I'll have to have the inside of the bend heated even with the outside, but the outside will need to be a larger area 'glowing' than the inside. It's a bit tricky to say the least.

Any other thoughts on how to skin this one?

Thanks,
Eric

[r33pwrd]

What material is it??

[sgt_rock]

Mild steel - it's an exhaust elbow from a diesel rig.

[-Ray-]

No way to get a good bend without crushing it.

[g.mccormick]

You can try packing it with sand. That may help prevent some crushing.

[SilvaChris1]

A little late to the game with this response, but you might be able to cut some notches out, weld the seams, and the grind it down smooth. That's if you can't get the bend you need. You could also just cut a decent section of pipe out and use a silicon clamp deal.

[JoshHefnerX]

An old trick I had heard about is putting a spring around the outside. Helps keep from crushing. Also the sand is a good one.

Josh

[BigRed585Lbs]

Only solution is to use "Turbomatt"s idea on the thread he started.

[99-LS1-SS]

Here are two links that might help.

http://www.metalgeek.com/archives/2005/05/01/000047.php

http://www.rorty-design.com/content/sand_bending.htm