Miller Electric

Welding Discussion Forums

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

Results 1 to 4 of 4

Thread: 321 stainless

  1. #1
    Join Date
    May 2011
    Posts
    9

    Default 321 stainless

    I am needing a starting suggestion for settings for welding up some 2" o.d. tubing 321 with .035 wall. All miter joints and some butt welds. I have a dynasty 350. I will be plugging and back purging. What size tungsten and what size wire. Thank you in advance.

  2. #2

    Default

    that thin of a wall thickness, 0.030-0.035" wire, 347 alloy. I'd try to use pulse to stiffen the arc and reduce heat input. Ultimately it's up to you to try it out on scrap tubing first, but I'd try around 60-100PPS, 60A, 35-40% background, 40-50% on-time. Try it out on scrap, and fine-tune from there. Tungsten, anything good on DC such as 2%Th, 2%La, etc, etc will work just fine. 1/16" diameter, 3x taper length, pointed end.
    HTP Invertig221 D.V. Water-cooled
    Eastwood MIG175 w/spoolgun
    Eastwood Versacut40 Plasma cutter

  3. #3
    Join Date
    Jan 2015
    Location
    Tampa
    Posts
    35

    Default

    You will not need any wire. As long as you have solid fitups, walk the cup on it and fuse it. I weld process piping for a living and all 16/14/12 ga tubing is TIG welded without any filler. Adding filler will introduce more of a chance for the material to draw, especially if you have any gaps in your fit ups.

    Such a thin wall will not need any more than 40-45 amps. 1/16" tungsten will be best, 3/32 will work. I use 3/32" 2% thoriated on everything from 30-150 amps. The arc just starts better at certain ranges. Majority of process piping is done with miller maxstar 150s using lift arc method.
    Stainless process piping - welder & fitter

    Miller Dynasty 280DX
    Jet band saw
    Dewalt chop saw
    Assorted IR air tools and Metabos

  4. #4
    Join Date
    Dec 2008
    Location
    west central Florida
    Posts
    140

    Default

    Quote Originally Posted by CODE4 View Post
    Adding filler will introduce more of a chance for the material to draw, especially if you have any gaps in your fit ups.

    Such a thin wall will not need any more than 40-45 amps. 1/16" tungsten will be best, 3/32 will work. I use 3/32" 2% thoriated on everything from 30-150 amps. The arc just starts better at certain ranges. Majority of process piping is done with miller maxstar 150s using lift arc method.
    What do you mean by "draw" here? Maybe suck back?

    Walking the cup on a thin wall tube, I've never seen that done. I don't doubt you or your skills, just haven't seen that.

    BTW I'd really like to see a pic of that weld on thin wall tubing, fused by walking the cup. I'd think walking the cup would be too wide, spend too much time on a thin wall tube, fusion joint. Post that pic!

    If you had a 90 mitre joint, you'd walk the cup on that?

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/www.millerwelds.com/web/content/lib/footer.inc.php on line 79

Welding Projects

Special Offers: See the latest Miller deals and promotions.