Hey guys -

Beginner welder here. I use a Lincoln 135 with gas. I have welded some aluminized exhaust pipe together before, but never stainless steel pipe. Anything special I should know about?

It will be 16ga. I am thinking "B" for the heat setting and 2.5 or so for the wire speed. Any thoughts, tips, etc.?

TIA

 

make sure you get the correct gas mixture for stainless, its different from mild steel.

 

MIG on thin stainless isn't real easy. For exhaust, .023 wire will help so you don't burn holes in it. For gas, you need Argon. I've seen a 99% Argon, 1% O2 mix recommended. I've just used pure Argon with decent results (I've only done thicker stuff though with the MIG on stainless - most of the stainless I've done was with TIG)

 

You can do it, but its going to be tough. If i were you, i'd get a couple scraps, or some spare pipe and cut small sections out of it, and try different settings and speeds until you get it right, otherwise you'll make a mess of the pipe.

If you are planning to weld on the truck, remember to disconnect the batt, and that when welding upside down, you get much better penetration, so you'll have to move faster as you weld, else you'll just burn through.

 

i hate welding... i suck at it! good luck

 

are you using stainless wire?

 

I am using what came with the Weldpak 3200: A 2 lb. spool of .025" (0.6mm) SuperArc™ L-56 mild steel MIG wire.

So I assume I should get some wire made specifically for welding stainless steel and get another tank of gas, preferably 99% Argon and 1% CO2?

Dang, maybe I should just get aluminized piping since I live in a dry climate and don't have to worry about rust anyway. Plus I don't really care about bling, and could spray some black ceramic coating on the pipe once I was finished anyway. What do you guys think? Is SuperArc™ L-56 mild steel MIG wire and a tank of C20 ok for aluminized exhaust pipe welding?

 

i just asked because i dont think that you would want your welds rusting on a stainless exhaust.... just a thought
you can use mild steel wire no problem

 

Best bet would be TIG with argon or the special mix for s/s.

I have done a little s/s with MIG and I use the smallest wire (0.023) and the very lowest settings I can make work. Or just get some band clamps that fit the size tubing you are using.

 

u need trimix, (forget the %'s) but its helium, argon, and CO2
edit: trimix = (90%He, 7.5% AR, 2.5%CO2) for all position,
the other mixes are mainly for spray arc or single pas

 

For some reason I thought trimix, trimax (what ever it is) was argon,co2 and a small amount of o2. But I could be wrong.

I've heard of people welding stainless with just the 75/25 argon co2 mix but the welds will come out dark. But like other said, get some scrap and practice first. Most exhaust shops should have a scrap pile.

 

You should never mix dissimilar metals.