[mk1_oz]

I am sorry for this being another newbie asking about TIG issues.......

I have only just bought my TIG and am in the process of teaching myself (using the forums and YouTube videos). I am looking around for an evening course to do. I bought this;

https://www.welding.com.au/equipment/vi ... 200i-ac-dc

I believe it to be a good quality hobbyist rig. Bought a pedal for it but that has not turned up yet.

This morning I started my lessons on steel with decent success. Some nice looking welds. Some rubbish. Issues such as undercuts but nothing that I cannot research and work out how to improve.

This afternoon I moved to aluminium. I have a number of 1000 x 20 x 3mm strips to butt, fillet and corner weld. I cleaned off the new aluminium with a new stainless steel wire brush (dedicated to aluminium TIG welding) and initially I had results - not good results but I welded the metal and started to gt a feel for amps, balance and frequency.

Then it all stopped. For some reason I can no longer start an arc. The welder is trying and seems to pulse a weak arc at around 2 per second but it never settles. If I release the torch button it totally stops but whilst I keep the button pressed it continually tries at 2 second intervals. I had not change any settings between it working and not working. I cannot recall 100% but there was a time that I took a break and forgot to turn the argon back on and it splattered and stopped once it cleared the lines - not sure if this was related or not.

Settings at time of stopping (as far as I can recall);

• earth to positive and torch to negative on machine
  HF start (don't want to make things hard for me with lift TIG just yet!)
  balance around 65%
  frequency 120
  3/32 ceriated tungsten
  around 100A start and 85A running
  gas around 7LPM

What have I tried to fix;

• replace the tungsten
  regrind the tungsten
  change gas flow
  change all the settings on the TIG (one by one)
  reclean the aluminium
  change to new aluminium pieces
  move the ground clamp directly onto the aluminium

I tried to be quite systematic when trouble shooting but was really just stabbing in the dark!

I know there are probably a million things that could be causing this but where do you suggest I start? I have probably pushed the filler rod into the tungsten a few times but have reground a dozen times already. Maybe I need to take a reasonable amount off the end to ensure it is not contaminated?

[cj737]

You just created another thread with the same issue. Now your recommended solutions will be split across two threads, confusing everyone.

[Junior Welder]

Im not sure if this is your issue but IMO its worth a try.
Set the machine to stick welding DC electrode negative.
Do NOT use a foot pedal/torch switch or anything like that.
Set amps to 50-100.
Get a Clean piece of steel and put your ground clamp on. Also make sure all your torch connections are good.
If you have a manual gas valve on the torch, turn on the gas (if you don't thats ok. starting an arc without gas will contaminate the tungsten, but you want to find the problem, right?)
and scratch the tungsten against a piece of steel. Kinda like striking a match.
You should get an arc established.
If you do, the problem is most likely your torch switch/foot pedal.
If you don't get an arc, chances are your machine is broken.

[mk1_oz]

Disregard this thread and use my other one on the same issue......created twice due to not realising admin needed to approve before it shoes up........great start!!!