I am making all my own custom intercooler piping so I bought some mandrel bends to make my own custom downpipe and charge piping.

What I need to know is what do I need to weld stainless exhaust piping.

My friend is willing to weld it up for me and I trust him but he has a miller mig welder and he's using argon gas and the wrong type of wiring. He said he could prob tach it but couldnt weld it all up.

What should I do?

Have it TIG welded. Look at the piping in my sig. That's TIG welded aluminum. Unless your friend has an expensive MIG and is a really good welder it might come out a bit sloppy.

I'm not sure what type of wire is needed for the MIG and SS pipes. Just call a local welding shop. Good luck. I hope everything turns out great!

You should be using a tri-mix gas and stainless filler/wire. Have a shop do it, have him get the right expendables, or get a different material. You can get away w/ argon only if it's TIG'd w/ stainless filler.

First most, have him do it in a well vented area. Stainless emmitts fumes that are cancer causing. Argon is fine. A mix is better. His skill will determine what it looks like. Have him make a few passes on a piece that you know you won't need. Keep in mind that function comes first when welding... the way the bead looks will reflect how well the joint is also. If you don't like it then grind it and blend it. They do it on custom bike pipes all the time.

Originally posted by Erik
First most, have him do it in a well vented area. Stainless emmitts fumes that are cancer causing. Argon is fine. A mix is better. His skill will determine what it looks like. Have him make a few passes on a piece that you know you won't need. Keep in mind that function comes first when welding... the way the bead looks will reflect how well the joint is also. If you don't like it then grind it and blend it. They do it on custom bike pipes all the time.

you think his wiring will be okay??

What kind of wire is he using? How does he know it's wrong? What wire does he use weld regular mild steel?

If he's using MIG, stainless wire, and straight argon gas will be fine. I've used my MIG on stainless with just normal argon/c02 mix with steel wire, and it welds just fine. It just wont be a stainless weld,and it will look odd(and can rust). I can make my MIG welds look damn near like TIG too :)

He is using regular steel wire yes. So I guess it would be fine as long as I just put some good paint on it. I dont care that it isnt stainless welds because it WILL be painted.

Originally posted by XtremeRS
If he's using MIG, stainless wire, and straight argon gas will be fine. I've used my MIG on stainless with just normal argon/c02 mix with steel wire, and it welds just fine. It just wont be a stainless weld,and it will look odd(and can rust). I can make my MIG welds look damn near like TIG too :)

I can tell you didnt mean to toot your own horn...but beep beep...lol

You can MIG stainless just fine, but keep in mind the welds themselves won't be stainless and can rust, while the pipe won't.

Originally posted by DarkOne
You can MIG stainless just fine, but keep in mind the welds themselves won't be stainless and can rust, while the pipe won't.

But if the welds themselves are coated with some paint wont that keep them from rusting?

I'd be worried about the different expansion rates, aka cracking at the weld.

Stainless likes to to expand at extreme rates (which is why you generally put slits and progressively larger bolt holes in stainless manifolds), where as mild steel does not.

Relax man. Have your buddy weld it up and throw some paint on it. The expansion rate of different types of steel in your application are not really an issue. Have your buddy lay some beads down and get a boost'n. If you are that worried, get some weld through primer (which is what I use if I have to section panels before I paint older cars) weld it together, and then paint. The most you're buddy can f-up is to forget to back-fill the end of the previous bead if he's a decent welder. I'm guessing that you are running under 30 psi, so you should be more worried about leaks. I use a flashight and turn the lights out. Put the light in the tubing and inspect the weld for light. Worse comes to worse, welders are about $40/hr. I'll do it for a 12 pack.

Good tip on the flashlight suggestion!!!

Thanks Erik you've been really helpful

Update is that me and My friend are just going to "mock" and tack, and we have another friend that owes us some work so he is going to tig the rest of it up. I'm very excited about boosting.

All I need is my mandrel bends to get here dammit!!

reason I am getting all this help for free is that I've put a crap ton of ours into my friend's 1967 fastback mustang that we are restoring.

Cant leave you hanging so here is a preview!!!
302 naturally aspired 500 hp on the dyno, Total control rear coilover setup and Mustang II front end. You will see this car in some mustang magazines soon I can gaurentee. (the hugger orange wont be there for long, black w/ silver stripes and center of wheels will be black w/ polished lip

Super sexy! Good luck to your 2gnt boostin project ScreaminE.