Green flash...

[Ali]

I've a little bit of TIG welding to do at the weekend, and last time I used it I remember having problems - at the time the solution was to use the MIG. I've a feeling this will be something embarrassingly obvious to those in the know, but I think I checked everything I could think of at the time.

R-Tech ACDC 161 DC - no foot pedal connected. Mild steel, DC.

I sharpened the tungsten (lanthanated) in the usual way and made sure everything was squeaky clean.

Strike an arc and all I can see is a great bright green ball where the pool is supposed to be - the mask darkened but it was basically as though it hadn't and I had a little glare afterwards. I thought it was the mask so messed about and changed the battery, tested in the sun, same. Tried another mask, same. Swapped tungstens, (although I'd miraculously not dipped it, and the spot of weld itself looked OK considering it was done blind (to be honest, peak ability for me). Same again. Checked all the settings on the welder, which I barely touch anyway other than amps. Checked gas (pure argon).

What have I broken now?

 

[Robert Weaver]

What polarity are you using?

I found the following work...

Mig
Gas - return-ve, torch+ve DCEP
Gasless - return+ve, torch-ve DCEN

TIG
DCEN
Steel sharp electrode, DC
Al balled electrode, AC 100-120 Hz -20-35%
balance

 

[Misterg]

What have I broken now?

What gas? But I suspect it's your mask not triggering properly from the TIG arc.

 

[Morrisman]

I have one of those Ginour true colour masks that seem very popular, and it doesn’t darken properly if there’s much sunshine coming through my workshop window, leaving me staring at a bright ball of fire.

 

[Popcorn]

I found the same with my mask, increasing the Sensitivity fixed it.

 

[Robert Weaver]

I got a parweld helmet, which leaked a lot of background light in. I fitted a fabric collar to cut down reflections. Can post an image if it helps.

 

[Ali]

What polarity are you using?

I found the following work...

Mig
Gas - return-ve, torch+ve DCEP
Gasless - return+ve, torch-ve DCEN

TIG
DCEN
Steel sharp electrode, DC
Al balled electrode, AC 100-120 Hz -20-35%
balance

DCEN.

@Morrisman it’s pure argon.

Haven’t had this issue before with the same setup.

It sounds like I might have two dodgy masks. I’ll have a closer look over the weekend and update.

Thanks for all the input.

 

[hotponyshoes]

You can test a mask by pointing a TV remote towards it

 

[roofman]

I have a Lincoln mask that does the same with TIG..so blinding i cant see, cheaper BOC mask and its fine.

 

[carbon]

What current are you welding at? Some masks don’t react very well at low amps

 

[Turbo]

I clicked on the link thinking it was about an environmentally friendly streaker. Silly me!

 

[Memmeddu]

I clicked on the link thinking it was about an environmentally friendly streaker. Silly me!

I heard about the green flash in squirrel boy many years ago when I was a child

Although nobody said about contaminations but it usually flashes in blue , green happens only when you touches the tungsten with the aluminium filler rod

 

[Ali]

Still happening, new mask now. I usually run about 10lpm on the gas but increasing it seems to help - I'm right near the end of the bottle and its 5 yrs old, if that makes any difference

Anyway, it's definitely not me dipping it in, although as soon as I'm blinded I generally do

Might get a new bottle & new set of tungstens. Seriously considering selling my Rtech TIG and Clarke MIG and pooling the funds for one decent MIG.

 

[Popcorn]

Are you sure it's not galvanised ?

 

[Ali]

Are you sure it's not galvanised ?

100% sure

 

[voipio]

The problem is caused by the DC arc being too stable for the helmet to respond reliably. It needs a flickering light from the arc to trigger the autodarkening. Try increasing the autodarkening helmet's sensitivity and increase the delay time. Also try and add a bit of pulse to the arc current, to stimulate the helmet's sensor circuit.

 

[Ali]

The problem is caused by the DC arc being too stable for the helmet to respond reliably. It needs a flickering light from the arc to trigger the autodarkening. Try increasing the autodarkening helmet's sensitivity and increase the delay time. Also try and add a bit of pulse to the arc current, to stimulate the helmet's sensor circuit.

The helmet works on the test button though, and directing at other light sources - it is darkening. I’ve tried 3 different helmets and never had this before with two of them. I’m fairly convinced the gas is at fault, somehow, but I probably won’t buy any more for a while as the workshop is getting moved soon and mig will be more useful to me.

 

[voipio]

That's the thing, though, it works on other light sources, whose light is probably flickering if they're mains powered. The light may look constant, but probably isn't. Try keeping the helmet pointed at the sun, whose brightness is stable. The lens will probably go "clear". A good DC TIG welding machine will give a very stable arc current.

 

[carbon]

I’m fairly convinced the gas is at fault

Surely the mask will work with gasless wire as well as wire with gas when using a mig welder.

You didn’t answer my previous question

What current are you welding at? Some masks don’t react very well at low amps

You haven’t mentioned what current you are welding at as this can make a difference, even some of the miller masks struggle with low currents and have a setting that doesn’t rely on the arc to darken the mask

 

[Ali]

That's the thing, though, it works on other light sources, whose light is probably flickering if they're mains powered. The light may look constant, but probably isn't. Try keeping the helmet pointed at the sun, whose brightness is stable. The lens will probably go "clear". A good DC TIG welding machine will give a very stable arc current.

It does nothing outside just now, but there’s no sun. By go “clear” do you mean it will just do nothing?

Surely the mask will work with gasless wire as well as wire with gas when using a mig welder.

You didn’t answer my previous question

What current are you welding at? Some masks don’t react very well at low amps

You haven’t mentioned what current you are welding at as this can make a difference, even some of the miller masks struggle with low currents and have a setting that doesn’t rely on the arc to darken the mask

This time I started off quite low as the workpiece was small and easy to get a lot of heat into, about 30-40A. Later on I did some at around 70A and there may have been some improvement but it wasn’t exactly night and day - still happening. Yes I’m sure it would work with gasless wire but I don’t have any of that either

I’ll try to do a bit more experimenting at higher amps. Just a bit weird that I’ve used the same kit for several years and never had this issue before.