Weld strength advice

[Westerngeophysical772]

Hi there. As its £500 to replace my cars exhaust I decided to but a MIG from steve with half the money and repair the system thats on the car. I want to weld a stainless steel pipe which I have sleeved into the CAT which is aluminised mild steel, I will be using mild steel wire with CO2/argon gas, will it make a good enough weld to hold?. Thanks in anticipation

 

[STOCKSY]

hi im pretty sure using mild steel wire will not weld stainless very well if at all

 

[Country Joe]

It'll be just fine, but the weld will rust, as the filler wire isn't stainless, just as any mild steel weld would.
CJ

 

[Westerngeophysical772]

Diff opinions there, but I will weld it up and give it a go. thanks folks

 

[STOCKSY]

lol learn someting new everyday , never actuallly tried it myself just was going on wot i was told

 

[hotrodder]

Hi there. As its £500 to replace my cars exhaust I decided to but a MIG from steve with half the money and repair the system thats on the car. I want to weld a stainless steel pipe which I have sleeved into the CAT which is aluminised mild steel, I will be using mild steel wire with CO2/argon gas, will it make a good enough weld to hold?. Thanks in anticipation

Probably missing something but if it's a sleeved joint why not cut a couple of slots in the pipe and use an exhaust clamp

Stainless is a type of steel it's just got some extra stuff* in it that makes it stainless. There are specific wires around for welding mild to stainless as you can end up with a brittle weld if stainless is welded with mild steel wire or visa versa. Won't be an issue for a car exhaust, even less so with a sleeved joint. As said the weld will rust (along with the mild steel side of the joint) but mild steel argon/CO2 mixes will mess with the stainless properties of stainless steel even if the correct wire is used

* a technical term, more detail in the MIG welding different steels section