Welding stainless

[kev234]

Hi , having just bought myself another quality vehicle, my wife is complaining about the noise the exhaust makes. It's blowing a bit but not enough for me to care. Anyway to keep the peace I decided to take a look. One of the welds has cracked (probably due to vibration) however a previous owner has fitted a stainless steel system. I have a mig and am using argoshield light. Is it a case of just using stainless wire or do I need a different gas?
If I need a different gas can I get it in a disposable as I don't do any stainless welding and don't want a big bottle?
Am I likely to encounter any problems with carbon deposits inside the exhaust?
All advice gratefully received
Kev

 

[BillJ]

Personally, I'd use stainless wire (I have used 308) and Argoshield. There shouldn't be any load on the weld, although it sounds like there might be, so no need for perfection unless you really care about it looking shiny. If you do, you can get pure argon in disposable bottles.

I'd be having a look to see why the weld cracked. Perhaps the system hasn't been well-designed and there is some stress on it that shouldn't be there.

 

[Weldingartisan]

It's probably cracked because commercial stainless exhaust systems are made from low quality tube and cheap consumables! W/A

 

[kev234]

It's cracked as some young whippersnapper has fitted a larger backbox (to impress the ladies no doubt) and it is not supported correctly. I will rectify this when I weld it up.