Stainless to mild steel, mig

[HiProfile]

Hello, been reading about welding for a few months, and finally got a Lincoln 3200HD (rebadged 115v sp135). Basicly for personal hobby usage.

My question that I can't seem to find is MIGing stainless to mild steel. I'm making an exhaust for my turbo project - all the tubing is mild steel, and the flex pipe is stainless. I'd have prefered not doing any stainless, but I'm kinda stuck. I just bought a tank of 75/25 arg/co2 and have the normal copper-coated mig wire. Tubing I believe is all 16ga metal, 3" dia.

Is this doable? And by doable, I mean it only needs to last as the aluminized tubing, yet take the torquing/vibration from a 300whp 4-banger. I'd rather not get stainless wire or special gas, since I'll be doing stainless much at all with this welder. Thanks, I appreciate any info.

[MAC702]

Go for it. Since you're not concerned about the corrosion protection of the weld, and it's not structural, just weld it with your steel set-up.

If you post your location, though, sometimes you get lucky and live near one of us that could help you out.

[HiProfile]

Well, it has to be as strong (maybe a bit stronger) than the mild to mild welds. The flex pipe section is where most of the movement is for this exuast.

And if I could get anyone local to guide me through stuff, or even just let me watch them weld, I'd be so happy. For some odd reason, I'm more interested in welding than I have been in anything lately (even girls ). You could say I'm like a sponge atm.

[MAC702]

Are you going to be grinding down the surface of the welds? If not, you should be good to go. If you're going to grind them smooth, which removes the cap reinforcement of the weld, then I would probably suggest the maximum strength of the proper filler, which would be ER309 stainless. This can still be welded with your steel mix gas, but the tri-mix would still be the best choice for maximum results.

[Rojodiablo]

I agree- just go for it. The SS spool wire is usually 308. You can use it, it works great. But the mild is going to give you a good weld- it will flow a bit nicer than the SS until you have more experience with the mig welder. And just stick to your regular 75/25 gas mix. I weld stainless D rings and cleats on truck racks all the time, and they are very secure. I just use the standard steel wire. If you do a good job with the weld, you are going to be fine.

[Roy Hodges]

I hate to be a "spoil sport" , BUT -if you're welding S S to steel , with JUST steel wire ,( which NO welding equipment manufacturer recommends ) for customers , and something comes loose , your company can be sued , big time . You know how it is , today . law suits , law suits , on & on . You should ask the manufacturer, or the A W S before recommending that .

[Rojodiablo]

Originally Posted by Roy Hodges

I hate to be a "spoil sport" , BUT -if you're welding S S to steel , with JUST steel wire ,( which NO welding equipment manufacturer recommends ) for customers , and something comes loose , your company can be sued , big time . You know how it is , today . law suits , law suits , on & on . You should ask the manufacturer, or the A W S before recommending that .

Let's be real here. I am welding cleats and D rings to a truck rack. I have hauled 1,000lb lumber loads with them, used all kinds of chain, cable, nylon and rope tie down methods to lean on them. And there is not NEARLY enough stress on a weld that is 1.25" long, full wrap around the part,(3/8" SS cleats) to .095 or .120 steel. A chassis, I agree. But he is asking about a turbo exhaust port.. So for that, I STILL say just burn that thing in, and go with it.