Technical Bending stainless exhaust

I'm trying to bend 1.5 sch 40 for an exhaust. I'm having difficulty and I was wondering if anyone had any suggestions thanks in advance.

 

I'm not positive but I think schdle 40 is a little too thick, you can probably bend it on a Greenlee or Hossfield tubing bender but I don't think an exhaust bender will do it.

Pat

 

yeah , schedule 40 sounds think......what does the wall measure?

 

The wall is .145. I turned it down on a lathe to .08. All I have is a tubing roller and it crushed it pretty good.

 

You don't use Schedual 40 for exhaust work. That is pipe and not tubing. I bought thousands of feet of different sizes of sch 40 stainless pipe for the company I used to work for and don't remember seeing any bends outside of some cast stainless bends. Even sanitary stainless tubing which is highly polished doesn't bend well. You have to buy the mandril bends and weld them in on that.
One of my old vendors who sold me most of my stainless tubing haulestd his 34 Ford to Portland Oregon to have Lonny Gilbertson weld up a stainless exhaust system and if I remember right the stainless tubing he carried along with him wouldn't bend right and they ended up using stainless exhaust tubing for most of it.

 

So no bending the stainless? Just buy mandrel bent sections for the bends?

 

http://secure.chassisshop.com/partlist/6206/ stainless donuts
http://www.pro-werks.com/partlist/980/ same product

 

That's a pretty sweet product pitman. I think I'll try that out. Thanks for the assistance.

 

They're right about getting several bends out of one, and the wall thickness is good.
As to welding, keep the air (and fume) moving away from you. Chrome6 can be a real problem
when welding SS. Read the exposure data in the MSDS-online world. I could find no "minimum" exposure limit!

 

Kind of scary, but I'll be sure to keep well ventilated.

 

To be done at home, this is probably the easiest way. Stainless tube does bend ok though, you just need the right gear to do it. After all, the weld in bends were bent by some one...

 

even stainless tubing made for exhaust systems doesn't bend too well. it has a tendency to kink and wrinkle. I don't like it. I have seen some aluminized pipes that I bent up almost 30 years ago and they are still going strong. A couple sets of muffler but still the same pipes. All this stainless stuff is more for bragging rights IMHO

 

This exhaust is actually going on a safari helicopter. And the man who owns it wants to duplicate the stock stainless one that company sells with a few additions. I may end up making more of these so duplication is a must in the future. I think he wants stainless to hold up better in the elements.

 

What type of tig machine do you plan on using?

 

Probably a synchro wave 250. But I've got a dynasty 200 and an xmt 304. For 16ga I'll run about 62 amps, and the resonator is 14ga which I'll run around 75 amps. Since it's not food related I'm not planning on purging anything.

 

I have a Pro #1 bender that I have use to bend stainless but I had to add a tab with a bolt on the outside shoe to hold the tubing in the die so it would not slip. Then I could make the bends without kinking the tubing. But the radius was not a real tight one.

 

I deal with welding and prepping stainless pipe every day. If your using shed 40 pipe then you should just get the weld fittings you need to make it as you need it. That being said shed 40 is way to thick for exhaust . I used shed 5 tubing plenty thick for what you need . You can find weld fittings at any reputable plumbing supply ( not Home Depot ) or you can get lucky at some scrap yards

 

Start to the resonator.

 

I've built headers out of stainless. It has to be "mandrel bent". The mandrel supports the pipe from the inside as it is bent and prevents the crinkling and collapsing. Because of this, I just buy some assorted mandrel bends. There's lots of sources, just google "mandrel bent stainless".
Here's a couple of pics of some I build from .062 SS. Everywhere there is a bend, there is a weld. When polished, the welds disappear. Those headers are 15 years old and still look just like the pic and never turn blue. If you have the patience, they're worth it...no maintenance ever.