mig welding stainless

[jasongtr]

my car project is a slow old project but eventually (read 12 months away) ill be at the point to think about an exhaust, ideally it will be stainless and id like to do it myself, is MIG welding (with my portamig 215) stainless steel as simple as using stainless wire, or are there other things to consider, such as can i still use the same argoshield light gas for instance.

cheers

 

[Welderpaul]

You need stainless wire and a gas such as BOC Stainsheild.

 

[jasongtr]

ok cheers. ill look into that nearer the time, i assume the argoshield is a big no no for stainless then

 

[BrokenBiker]

i think there is too much carbon dioxide in argoshield. Ideally you want less than 3% co2 welding stainless afaik

 

[jasongtr]

wonder if i can tag the stainless gas onto my volkszone argoshield deal....

 

[Jan]

I thought that the BOC Argoshield (Volkszone) variant was only 2.5% CO2.

 

[hotrodder]

Argoshield light is 5% CO2 and 2% O2. Argon + 2.5% CO2 falls under a whole family of gas mixes that BOC call 'specshield', their stainshield MIG* is a tri mix with some of the argon replaced with helium and stainshield comes in light/universal/heavy flavours like argoshield

I doubt you'll be able to convince BOC to add either of them onto the forum deals, AFAIK neither of them exist in a size Y and specshield is size W only

CO2 has a slight oxidising effect as it's dissociated in the arc to CO + O. While it physically works too much CO2 results in oxidised welds and potentially carbon pick up in the weld both of which can make the result 'less stainless' than it should be


* there's also stainshield TIG which is Ar + 1.5% hydrogen

 

[Jan]

For some reason the tag on my Volkszone bottle just specifies argon and CO2, but not O2.

 

[BrokenBiker]

just as side note I have used 5% co2 95% argon on stainless and it worked but I only did a few small welds so not enough to really test it