whats going wrong?

[tomwood]

Only started playing with my new tig the other day and im having problems. I started off fine but without changing any settings im finding the arc more unmanagable and its beginning to spatter and get really hot. What do you think?

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The first pic is when i first started and the other two are today.

 

[tomwood]

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[tomwood]

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[shenion]

Looks like you have lost gas coverage. Either out of gas or a break in the line.

 

[ChrisJohnsSculpture]

Yeah definitely looks like an issue with gas coverage or possibly a blunt or contaminated tungsten. The tungsten electrode should be smooth and shiny coming to a well defined point with a small flat at the end. If it's dull, grey or lumpy it need to be re-ground.

Contamination of the tungsten may be caused by :

•Touching the filler rod or the weld pool with the electrode
•Not enough gas flow (should be somewhere in the 3-8 lpm range)
•Post-flow gas timer set too low
•Using the wrong gas (should be pure argon)
•Tungsten too small for the current being used
•Not cleaning the steel well enough

Poor gas coverage may be down to :

•A draught blowing the gas away
•tungsten sticking too far out of the cup (should stick out by about the cup aperture diameter)
•wrong gas
•gas bottle empty
•a leak or blockage somewhere (check all connections are tight in the gas line and torch) and that the gas lines aren't damaged of kinked.
•ceramic cup too small for the job



If you've got no gas at all probably the first thing that will happen is that the tungsten will burn up.

Also it looks like you'v been welding on hot rolled sheet without removing the mills scale, for TIG you need to be grinding the scale off down to bare metal.

A further point is that you appear to be coming off the power too abruptly which is causing pits at the end of each weld. If you're using a foot pedal back it off slowly over a few seconds at the end of each run, if not and your machine has a 'down slope' setting set it a bit higher and don't pull the torch away too quickly at the end of each weld, which is always a temptation if you are used to stick welding.

 

[tomwood]

Thanks for the reply guys. I thought it may be a gas problem but its flowing through at 7lpm without any apparent leaks. Ill try again today and update

 

[hotrodder]

While you're playing today take a pic of the tungsten and take a pic of the gas cylinder, specifically the label that says 'pureshield argon', pure argon or something along those lines.
If, when you take a pic of the gas cylinder it also has CO2 written on it then there's your problem
The only other thing that hasn't been mentioned is a torch that's assembled inside out/back to front. Not that uncommon as instructions are for girls, WILL result in a leak that draws air in. There's pics/diagrams in the TIG tutorial/FAQ

 

[tomwood]

Thanks again guys, seems like you've got a really friendly forum here.

Discovered my problem, rather embarrased to say I had the electrode collet the wrong way around! All part of the learning process I suppose.

So got up and running just in time for the gas bottle to run empty, typical ay!