[EJ20]

As per the title, first time trying TIG A/C with aluminium and it seems like the tungsten instantly spits the moment the arc is made.

Info: 3/32 green tungsten, ground to a weak point and flattened off, regular no.5 cup, tried 10-20cfm argon

Clean aluminium extrusion (just a practice peice to get the feel, approx 4mm thick)

Tried 80-140amps, AC balance from 75-50, no change

I've got a couple of photos to visualise what's going on, DC with stainless and mild is absolutely fine

Any help greatly appreciated!

[weldin mike 27]

Forgive me if I'm wrong, but if you have an inverter welder, green (pure) tungsten isn't the best option. Try a 2% lanthanated one. Pure is better suited to big old transformer machines. If you have the transformer, I'm not sure what's going on.

[tweake]

As per the title, first time trying TIG A/C with aluminium and it seems like the tungsten instantly spits the moment the arc is made.

Info: 3/32 green tungsten, ground to a weak point and flattened off, regular no.5 cup, tried 10-20cfm argon

Clean aluminium extrusion (just a practice peice to get the feel, approx 4mm thick)

Tried 80-140amps, AC balance from 75-50, no change

I've got a couple of photos to visualise what's going on, DC with stainless and mild is absolutely fine

Any help greatly appreciated!

splitting or spitting?
transformer machine or inverter?
what machine?

140 amps is probably a bit low but should be ok to start with.
ac balance will be 75% or 25%, try both some machines are labeled back to front.
is the aluminium actually clean. when using scraps watch for oil or coolant soaked bits.

[studioq]

I'd be interested to see the grind on the tungsten too. Some pictures would help. I had a hell of a time when I started on aluminum. I've had a few electrodes ball up and melt away immediately - rather than split. My issues were mostly due to shielding gas flow - among all the other noob stuff...

[LtBadd]

Transformer or inverter, pure tungsten isn't going to stand up as well as one of the blends. Pure tungsten is meant to be balled not sharpened.

From DGP Tungsten Guidebook

2.3.5 Pure Tungsten (EWP Electrode Classification: Green Stripe)
Pure tungsten electrodes (EWP) contain a minimum of 99.5 percent tungsten, with no intentional alloying elements. Pure tungsten has a very high work function, and thus it is more difficult to start and produce a stable arc than other materials. Also, because of the high work function, the temperature at the tip is higher and grain growth occurs. This leads to an unstable arc, starting difficulty, and a shorter service life. Pure tungsten is only used for AC welding; however; better alternatives are available.

[cj737]

A tungsten that splits immediately is a sure indication of a tungsten that was snapped, cut, or broken off in length. In particular, pure tungstens are sensitive to these types of fractures. Always grind the tungsten in half to shorten it, then grind your tapers in for the tip.

[EJ20]

Thanks for the replies, I'll see if I can get these photos to work

20191228_141810.jpg (21.76 KiB) Viewed 4045 times

20191228_141810.jpg (21.76 KiB) Viewed 4045 times

[tweake]

my first thought is gas issue. however just switching over to stainless will show that up straight away.

however whats left of the tip of the tungsten suggests your blowing the tip off the tungsten.
check the balance setting. to much cleaning action will put more heat into the tungsten. pure tungsten will not handle a lot of heat. the grey look of the tungsten also suggests its getting way to hot and/or lack of post flow.

[VA-Sawyer]

I think tweak nailed it on the head. For setting AC balance, see if it is setting the percent of EN (Electrode Negative) time, or the percent of Cleaning time. Cleaning happens during the EP Electrode Positive part of the AC cycle. You want something around 25% cleaning time, which would be 75% EN time (25% EP). Some welders show you %EN, and some show you % Cleaning (%EP) . It is like saying a fuel tank is 25% full, or 75% empty. Both indicate the same amount of fuel.
The thing to keep in mind..... during the EN part of the AC cycle, the heat is going into the metal you are trying to weld. During the EP(cleaning) part of the AC cycle, the heat is going into the electrode.
Do you really want the heat going into your electrode 75% of the time?

[EJ20]

This is why I'm confused, I used both extremes of AC balance with the same results.

I might have a gasflow issue however, I just tried some stainless and it came out like there was very little gas, so I'll trace what's going there.

[Coldman]

You've been prompted a couple times for power source and setting information but you're not providing. Are you just playing games?
We are just guessing here until we get the INFORMATION !!!

[BillE.Dee]

Not for certain, EJ, but I've found that the green stuff doesn't work so well on an inverter machine...kind of fizzle rather than arcs (for me anyway). Also looks like a gas coverage problem...try getting closer to the base metal and maybe a larger cup. Use the smaller one when you get hood time. I didn't notice thickness of the base metal,,kind of hurried (my wife is right behind me with a rolling pin). Slow down, practice position without power, then work into power without filler rod, then work into adding filler rod. Slow down, grasshopper...the learning curve for welding is / ... the learning curve for tig welding is |. Try to watch some of Jody's videos and don't get all jazzed up.

[EJ20]

You've been prompted a couple times for power source and setting information but you're not providing. Are you just playing games?
We are just guessing here until we get the INFORMATION !!!

Apologies, it's an inverter, made by BOC gas, which is linde in the US. 185amp AC/DC machine.

I made a mistake in my initial post, I actually used between 20-75% AC balance with no change.

Even at 80 amps it instantly destroyed the tungsten.

Two brand new tungstens, not cut, and just a pretty weak grind on it, as I wanted to see how ball formation worked

[EJ20]

Not for certain, EJ, but I've found that the green stuff doesn't work so well on an inverter machine...kind of fizzle rather than arcs (for me anyway). Also looks like a gas coverage problem...try getting closer to the base metal and maybe a larger cup. Use the smaller one when you get hood time. I didn't notice thickness of the base metal,,kind of hurried (my wife is right behind me with a rolling pin). Slow down, practice position without power, then work into power without filler rod, then work into adding filler rod. Slow down, grasshopper...the learning curve for welding is / ... the learning curve for tig welding is |. Try to watch some of Jody's videos and don't get all jazzed up.

Thanks for the reply, I'll pick up some alloyed tungsten after the holidays. I've only got red which everyone says isn't AC suitable.

I was close to the base, like 4mm or just over an 1/8th inch, the tungsten was murdered so quickly I don't have time to actually see what's happening. Hence the reaching out for help.

I've had zero issues with stainless welding, so that's why I'm so baffled, it's possible I've had a regulator or machine issue that was effecting gas flow. Havnt had enough time to trouble shoot it.

[VA-Sawyer]

I downloaded the manual for your welder ( BOC SmoothArc 185 AC/DC) It looks like the AC Balance knob is setting % Cleaning Time. So set it to about 25%

[tweake]

Apologies, it's an inverter, made by BOC gas, which is linde in the US. 185amp AC/DC machine.

I made a mistake in my initial post, I actually used between 20-75% AC balance with no change.

Even at 80 amps it instantly destroyed the tungsten.

Two brand new tungstens, not cut, and just a pretty weak grind on it, as I wanted to see how ball formation worked

i probably have the same machine.
crank the balance knob hard to the left then come back to the first line. should get you in the ball park.

pure tungsten will be an issue. use anything else you have, doesn't really matter to much a the mo.
if you have a 3.2mm tungsten use that with 45 degree grind.
otherwise i suggest starting with thinner material ie 2mm aluminium. thats simply to make it easier on whatever tungsten you have.

[EJ20]

Apologies, it's an inverter, made by BOC gas, which is linde in the US. 185amp AC/DC machine.

I made a mistake in my initial post, I actually used between 20-75% AC balance with no change.

Even at 80 amps it instantly destroyed the tungsten.

Two brand new tungstens, not cut, and just a pretty weak grind on it, as I wanted to see how ball formation worked

i probably have the same machine.
crank the balance knob hard to the left then come back to the first line. should get you in the ball park.

pure tungsten will be an issue. use anything else you have, doesn't really matter to much a the mo.
if you have a 3.2mm tungsten use that with 45 degree grind.
otherwise i suggest starting with thinner material ie 2mm aluminium. thats simply to make it easier on whatever tungsten you have.

A fellow New Zealander, nah I'm on a 2.4mm set up. I tried the balance hard left and right, but I suspect I've got an argon flow issue. When I have time I'm going to get to the bottom of it.

[EJ20]

Thanks to all that chipped in with advice, root cause was a faulty argon regulator showing incorrect flow, that caused me to swing the balance much too positive in search of a proper arc and further kill my tungsten.

[tweake]

Thanks to all that chipped in with advice, root cause was a faulty argon regulator showing incorrect flow, that caused me to swing the balance much too positive in search of a proper arc and further kill my tungsten.

if it the stock boc reg they are the pressure type, they are fairly basic. also i've had trouble with the quick disconnects leaking.

[EJ20]

Thanks to all that chipped in with advice, root cause was a faulty argon regulator showing incorrect flow, that caused me to swing the balance much too positive in search of a proper arc and further kill my tungsten.

if it the stock boc reg they are the pressure type, they are fairly basic. also i've had trouble with the quick disconnects leaking.

The lowside gauge is forked, I had it set at 5 LMP, gave it a tap and suddenly it was at 25 LMP, wound it down and wouldn't go under 5, so who knows what the actual flow was, I'm guessing it was close to nothing. Swapped to the reg off my mig, and suddenly I've got a stable arc and I'm not exploding the tungsten haha.