Green flash...

[Ali]

When I next get a chance I’ll set up the big torch and weld some thick stuff to see if there’s any difference.

Meanwhile, does this mean anything glaringly (no pun intended) obvious? There are the tungstens I’ve been using

Fubar?

 

[voipio]

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

When an autodarkening helmet is pointed at the sun, it will generally go dark, but then, if it's kept pointing at the sun, it will go light again. If, at this point, you wave your hand in front of the helmet, to interrupt the sensor's view of the sun, it will go dark again. If you stop interrupting its view of the sun, it will go light again. The helmet's delay setting will determine how long the lens stays dark, before it goes light again.

There's nothing wrong with those tungstens, by the way. If anything, those nice clean points will help to create a nice stable arc, which is probably why the helmet goes light. Perhaps TIG torches should be fitted with a TV remote-like LED, to trigger the helmet's sensors.

 

[Ali]

Found the culprit. Was photographing something at the bench where I do my welding, and noticed the screen flickering. Switched off the work lamp and remembered I’d fitted an LED bulb at some point. Seems fine with light off. D’oh!

 

[Munkul]

Interesting, I didn't think an LED light would stop an ADR filter from working... Glad you found the solution.
To anyone else who has this problem, it is very tempting to think "the problem is the welding arc" because that's what your eyes tell you... But it's 99.9% always the ADF not triggering somehow.