Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process
rayhall
  • Posts:
  • Joined:
    Sat Dec 16, 2017 1:52 am

Hello Everyone,

I have a new TIG welder (UNIMIG 200 AC/CD) and it has many knobs to change settings. I am welding Aluminium and the tungsten is getting small balls on the tip. What could be causing this.

Ray.
Attachments
TIG_WeldProblem.jpg
TIG_WeldProblem.jpg (16.98 KiB) Viewed 1236 times
User avatar
  • Posts:
  • Joined:
    Sun Oct 27, 2013 10:57 pm
  • Location:
    Big Lake/Monticello MN, U.S.A.

It also looks to be splitting lengthwise.

What type tungsten are you using? Amps? Balance? Diameter?
Dave J.

Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~

Syncro 350
Invertec v250-s
Thermal Arc 161 and 300
MM210
Dialarc
Tried being normal once, didn't take....I think it was a Tuesday.
cj737
  • Posts:
  • Joined:
    Thu Sep 29, 2016 8:59 am

To Dave's point, it appears that you are snapping your tungsten which has caused fractures in its length. If you are using AC as the weld process, you don't want to use RED (thoriated) tungstens. Also, the AC balance will greatly effect the tip (looks like you're setup is wrong). Bundle those things together, and you get a tungsten that looks like that.

If you do need to alter the length of your tungsten, its best to grind it in half (use the edge of a grinding wheel to bevel it in two) then re-grind tapers into each segment. Snapping it, cutting, or shearing it will cause those micro splits.
rayhall
  • Posts:
  • Joined:
    Sat Dec 16, 2017 1:52 am

I have tried many settings and still get a problem with the tip of the tungsten. The big improvement was to go from 2% Thoriated to WZ8 Zirconiated. Not only did the tip problem improve, so did the welds.

I have the gas flow set to 10. I have tried pointed and rounded tip. The rounded gives the best result with WZ8 Zirconiated

Here is a picture of my current settings that I have found by trial and error. Also what the tip looks like now. Do they look correct for welding Aluminum ?

Ray.
Attachments
Machine Settings
Machine Settings
TIG_WelderSettings.jpg (50.31 KiB) Viewed 1064 times
Tungston Tip
Tungston Tip
TIG_Welding_Tungston.jpg (23.46 KiB) Viewed 1064 times
cj737
  • Posts:
  • Joined:
    Thu Sep 29, 2016 8:59 am

I prefer 2% lanthanated tungsten with an inverter. I start with a mostly sharp, tapered tip, then blunt it. I “ball it” by setting my balance to 30 until it balls (small, tight ball). Then I set my balance back to 70-75% and use 60-150hz for welding depending upon the application. I’ve never used Zirconium tungstens, so I have no clue about your settings.
MarkL
  • Posts:
  • Joined:
    Wed Jun 15, 2016 7:09 pm
  • Location:
    Far west Chicago burbs

rayhall wrote:The big improvement was to go from 2% Thoriated to WZ8 Zirconiated. Not only did the tip problem improve, so did the welds.
My experience is zirconiated works good for AC on a transformer machine, but not very good on an inverter machine for either AC or DC. The ball on the tungsten should be more like the tip on a pencil that you've used for a long time, smoothly rounded off. The tungsten in your photo has a tip that looks irregular and not symmetric, almost like a blob of the aluminum got on it.
Lincoln Square Wave 200
Lincoln 225 AC/DC
Harris Oxy/Acetylene torch
Post Reply