Weld exhaust

[RunningProblem]

I want to weld a muffler to my catalytic converter and my choices are aluminized steel or stainless steel. I have a MiG welder (180amp) with 0.035 ER70s6 and a flux core welder (90amp).
I have never welded aluminized or stainless anything. It’s going on the crawler toy so I’d like it to be secure and not ghetto fab. What is the advice you have besides paying someone to do it? Is using a flap disc on the aluminized muffler going to be enough to expose bare metal or is it already super thin and I’ll be making it thinner? I don’t want to fuck with clamps.

 

[rattle_snake]

clean and weld away. ER70 works fine on SS.

ER70/C25 on mild, aluminized, stainless mis-mash.

 

[Wisconsinite]

I used to work at an auto repair shop and we did a ton of aluminized tubing. I am not saying it's right, but we dd zero prep work to the tubing, mufflers, whatever... Just burnt it in. You will be fine.

 

[MigGunslinger]

I'd fire up that mig and tack, tack, tack all the way around it. That .035 is probably going to burn a bit hot to continuous weld. The aluminized pipe should be fine without prep, wipe it with acetone of its oily otherwise send it.

Goes without saying that your weld and the area around it will not have the corrosion protection of either the SS or aluminized sections.

 

[AKnate]

I'd fire up that mig and tack, tack, tack all the way around it. That .035 is probably going to burn a bit hot to continuous weld. The aluminized pipe should be fine without prep, wipe it with acetone of its oily otherwise send it.

Goes without saying that your weld and the area around it will not have the corrosion protection of either the SS or aluminized sections.

That's how I've always done exhaust and other thin metal. A good hot tack, a second for it to freeze, then light it up again. I usually end up blowing through after an inch or two bead, but if I turn it down, it's too cold until that point.

 

[M92PV4U]

Ss flexible coupling to aluminized exhaust 90° with mig er70s6, it'll be fine.

 

[RunningProblem]

clean and weld away. ER70 works fine on SS.

ER70/C25 on mild, aluminized, stainless mis-mash.

Looks good from this far away.


I went with 0.035 wire and turned down wire feed speed. Seems like it is in there good enough.

 

[RunningProblem]

I ended up doing 035 wire with the heat turned down. Tack welded spots and some short runs. Took my time. Move around. Allowed metal to cool. Seems to work.