the best way to weld stainless steel exhaust

[markie]

Hi `im trying to build a complete stainless exhaust system for my car. I`m a panel beater so i`m used to mild steel welding but stainless i`m struggling with for some reason. My biggest problems seem to be too much penetration leaving nasty lumps inside the pipe which I dont really want if I turn it down I seem to get messy tall welds that look awful. Any tips from you experts on what i`m doing wrong. It T304 that i`m welding using 308 wire 1mm is that o`k. My welders a oxford 180-1 which I believe is based on the portamig but it welds mild steel nicely so I hope that my welder isnt the issue. Any advice would be great

thanks mark

 

[TechnicAl]

what gas?
what thickness are you welding?

 

[markie]

hi thanks for the reply. the wall thinkness is 1.5mm and i`m using argon light. does the gas really make that much difference as i`m not bothered if its dull as i`m going to polish it anyway

thanks

 

[Rubber Duck]

Am I right in saying argon/heavy is best for SS.

Feel free to correct me if I'm wrong.

 

[Paul G]

I think the gas to use is Stainshield Light.
I believe it has a quantity of helium in its composition.
Cheers,
Paul G

 

[langy]

Yes the gas will make a difference, to be honest if your polishing after getting it tigged will make less work and give a better job.

hi thanks for the reply. the wall thinkness is 1.5mm and i`m using argon light. does the gas really make that much difference as i`m not bothered if its dull as i`m going to polish it anyway

thanks