Miller Electric

Welding Discussion Forums

Home » Resources » Communities » Welding Discussion Forums
Miller Welding Discussion Forums - Powered by vBulletin

Results 1 to 5 of 5
  1. #1
    Join Date
    May 2006

    Default Ar/Co2 for SS MiG ?

    I need to tack the slip joints on a 4" stainless exhaust system and was wondering if it's ok to use Ar/Co2 since this is about all I'm going to be doing with stainless. I want the welds to be permanent and strong enough to hold the joints together w/o clamps, but really don't want to buy a bottle of gas just for 6 or 8 tack welds.

  2. #2
    Join Date
    Sep 2005
    Salem ,Ohio


    I use 75/25 for SS. Its not the textbook gas but it works. If i was doing more i would use tri mix but i don't do enough to buy the bottle...Bob
    Bob Wright, Grandson of Tee Nee Boat Trailer Founder
    Metal Master Fab Salem, Oh 44460
    Birthplace of the Silver & Deming Drill
    1999 MM185 w/185 Spoolgun,1986 Thunderbolt AC/DC
    Spool Gun conversion. How To Do It. Below.

  3. #3
    Join Date
    Nov 2006
    Lake of the Ozarks MO


    You will be fine... just follow all the normal guidelines and all should go well
    Miller Dynasty 700...OH YEA BABY!!
    Miller Dynasty 280 with AC independent expansion card
    Miller Dynasty 200 DX "Blue Lightning"

    Miller Bobcat 225 NT (what I began my present Biz with!)
    Miller 30-A Spoolgun
    Miller WC-115-A
    Miller Spectrum 300
    Miller 225 Thunderbolt (my first machine bought new 1980)
    Miller Digital Elite Titanium 9400

  4. #4
    Join Date
    May 2006


    That's what I was hoping for. Thanks.

  5. #5
    Join Date
    Nov 2007
    Southern Louisiana


    If the stainless welding is for anything else please be careful. The stainless code is VERY specific about how much CO2 can be used. The issue is chromium carbides that will make the corrosion effect more rapid and lead to premature failure. More than 3% CO2 is not allowed according to table 3.5 of the prequalified clause in AWS D1.6 2007.

    That being said I realize you are not welding stainless structural steel, but the reasoning behind the limitation is sound. Clause 4 does allow for your own qualification testing.

    I would be careful as well if there is going to be dramatic heat fluxuations in the part.

    There, I have spoken my peace. You are free to do as you please, just be ready for what will come after it.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Warning: Function split() is deprecated in /mnt/stor3-wc1-dfw1/357822/357839/ on line 77

Welding Projects

Special Offers: See the latest Miller deals and promotions.