Tip contamination

[strobe]

hi guys , I recently started trying to tig weld and it's bl"'^*y brilliant for a minute or two then something happens an the "flame" goes all sideways and the tip is contaminated,not in that order. Regrind tip and start over
The question is why , I give it plenty of gas ( is too much possible ?)
And I put a 45deg tip point on as I grind tip

 

[WorkshopChris]

Is this AC or DC.
Is it possible that the tip of the electrode is dipping into either the weld pool or any filler rod and picking up contaminants.
Depending on what material you are working with i would expect to have a much longer angle than 45deg.

 

[eSCHEn]

Just to add - yes, too much can be possible. The idea is that as the gas pushes in at a high rate it pulls in air and you get problems.

Treat the pure argon (it is pure isn't it? you want no active gasses in it) as like double cream. Let it "pour" out the ceramic. Depending on what you're doing, 5lpm - 8lpm should be perfectly fine.

 

[Richard.]

Sounds to me like you've got a little arc wonder.
1st question is your not using a magnet on it or coiling up the return cable creating a magnetic field are you as this can deflect the arc direction.
Tungsten prep plays a huge part in the direction, sharpness and stability of the arc and 45 degrees is a bit steep for a DC prep. I'd go narrower. The point length wants to be 2-3 times the tungsten diameter really. Yes you can have too much gas and the effect can be just as catastrophic as too little. The forces of high gas flow create a turbulent effect which actually draws air into the shield contaminating both the electrode and job. Finally check for leaks. I've been working with someone today who has no end of contamination issues due to a small leak on his gas line. You not only let gas escape but you draw air in and the result again is unsteady arc, contaminated tungsten and weld.
Make sure your metal is nice, bright and clean.