Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process
JonF
  • Posts:
  • Joined:
    Thu Sep 23, 2010 1:11 pm

I seem to have forgotten how to TIG weld. I'm not sure what kind of steel I'm welding on, but I can get a puddle going pretty good for about 1/2 an inch, and then the puddle bubbles and spits, etc. I noticed that my gas lens collet was dirty, so I went to change it. I only have a 3/32 non gas lens collet but the cup that fits it is only 3/8". Is it OK to use 3/32 tungsten with this smaller cup?
jakeru
  • Posts:
  • Joined:
    Sun Apr 25, 2010 3:30 pm

For stainless it might be a little narrow (depending on amount of stickout you need, and how hot you are getting the metal.) For mild steel, it should be OK.
http://www.ckworldwide.com/tech-3.pdf

If you think you might be having shielding gas issues, make sure you don't have excessive tungsten stick-out or excessive arc length. For a non gas lens cup I would try and keep stickout to no more than 1/2 of the cup diameter. Gas lens cup can support as much as the inside cup diameter stickout with still ambient air condition.

If you are welding in a wind or draft, try and shield the wind, close the garage door, reposition or turn off a fan blowing into your weld area, etc.


Steel doesn't *need* really good shielding gas coverage to weld OK (get good, strong, ductile metal fusion), but you sure can make those steel welds look a lot prettier if you do (IE: treat it as if it were stainless steel, use a wide cup, plenty of post-flow, avoid getting the metal too hot, etc.) It makes the different between a "dull gray" look versus clean, shiney appearing weld beads, with "rainbow" oxide film colors.

For stainless it's critical to not to let it oxidize very much, in particular you want to avoid when the metal expands with internal/porous "gas bubbles", which makes it very weak and brittle, puddle won't flow well, etc. Oxidizing stainless I can't remember really "spitting" however.

Spitting could be from some kind of contamination, like rust, oil, water, maybe even zinc/galvanized coating. So ideally try and prepare your metals to a bright, shiney, dry, and solvent cleaned state.
Last edited by jakeru on Fri Sep 24, 2010 10:05 pm, edited 1 time in total.
JonF
  • Posts:
  • Joined:
    Thu Sep 23, 2010 1:11 pm

Thanks for the help.
kermdawg
  • Posts:
  • Joined:
    Tue May 25, 2010 8:16 pm
  • Location:
    All over, mostly southwest USA

Id try and figure out exactly what your welding on. Secondly be sure you clean it -real- good, theres no contamination in the tungsten, and your filler rod is real clean as well.
Signature? Who needs a F***ing signature?
sschefer
  • Posts:
  • Joined:
    Wed Aug 18, 2010 7:44 pm

Spitting can happen for about a bizillion reasons. Jakeru hit all the setup issues but not knowing what type of metal you have is probably the biggest contributor. Here's a thought, get out the grinder and do a spark test. The color of the spark will get you a realy close guess and then you can setup you equipment accordingly. I used to have a link to a spark guide but I doesn't work now. You can try some similar metals you have laying around that you know the type and compare them.
Highly skilled at turning expensive pieces of metal into useless but recyclable crap..
kermdawg
  • Posts:
  • Joined:
    Tue May 25, 2010 8:16 pm
  • Location:
    All over, mostly southwest USA

A -very- basic spark test guide. No color pictures but it does include a lot of differant types of metals/alloys.
http://en.wikipedia.org/wiki/Spark_testing

hope that helps. Be sure to pay attention to the colors that the sparks give off, as thats probably the biggest tell. good luck!
Signature? Who needs a F***ing signature?
Post Reply