auto welding mask

Post by **acmotor** » Sun, 21 Nov 2010, 20:41

OK, fell for this one.

My 12 month old auto darkening welding mask stopped auto darkening.
It has a small PVcell (amorphous) on the front and a rechargeable (!) battery.
I keep it in the box it came in to reduce dust and scratches.

The battery went flat and it wouldn't wake up so I saw stars !

Half an hour out in the sun and it has recharged and works fine again.

Lesson.... don't treat your auto mask like a toadstool and keep it in the dark.

The amorphous PV will probably keep the battery charged in reasonable ambient light.

Post by **coulomb** » Sun, 21 Nov 2010, 23:01

acmotor wrote: It has a small PVcell (amorphous) on the front and a rechargeable (!) battery.

Rechargeable? Huh. I suppose it makes some sense.

The same thing happened to ours a while back. It seemed to "fix itself" then fail again, but this would fit the pattern.

We didn't realise about the rechargeable battery, and bought another one. Mainly so we could compare them side by side; they seemed to work the same for a while. So it wasn't a change in sensitivity.

So now we'll store them in a sunnier location (under some roof polycarbonate) and see if that fixes the problem.

Thanks for the pointer!

Post by **acmotor** » Sun, 21 Nov 2010, 23:40

These masks can't be used to view non pulsing light sources such as the sun or a filament globe torch. They will just flick to dark once then stay clear.
I experimented viewing my HID torch (HF pulsing) and you can adjust the darkness control on the mask (9-15 ISO go dark units !). The HID discharge arc is an interesting grainy plasma ball at 11 and blacked out with 15.

Post by **7circle** » Mon, 22 Nov 2010, 01:00

Might be worth mod'ing them with a Li-ION upgrade. The self discharge of NiMH mini cells is pretty bad. or even a capacitor. Hoe much power does it take to run the LCD and sensor circuit?

It might have a button Li-Ion Already. I guess they stay charged from the illumination from welding too.

What do you mean ACmotor by "they will just flick to dark once then stay clear"?

Post by **Electrocycle** » Mon, 22 Nov 2010, 01:41

yeah both of mine work fine if you look at the sun with them.

I have one with a battery (not rechargeable), and another with no battery (no on switch, no adjustment - just works)

Post by **acmotor** » Mon, 22 Nov 2010, 02:02

The early model automask (1990s ? I had one) would dim with steady light (so could look at sun). The problem was they were a hastle when doing outside welding (I count my rod usaege over the years in km !). The later model ones I have used all just flick once when looking at sun i.e. they reject steady sunlight and only react to pulsing light as from arc/mig/tig deliberately. They react to the change of light so flick once when pointed to the sun.

I made this comment as I have seen people throw masks out 'cause they failed their 'sun test', yet the instructions clearly say that the circuitry is designed to reject the steady ambient and sunlight.

It is a well glued up module so I can't investigate inside.

Post by **T1 Terry** » Mon, 22 Nov 2010, 12:02

If anyone is thinking of buying an auto darkening welding mask, buy a good one. You can tell the difference by the adjustability, a good one has sensitivity adjustment, delay adjustment and darkness adjustment, all infinite adjustment not a 3 position switch. If you are likely to be doing welding in strange postions the 4 sensor unit is worth the extra money. Cheapies just have darkness adjustment. These are slower at switching, sometimes switch on while you are double stricking an arc etc and real eye damage is done very quickly and never recovers, you realise this when you get older and can't see in the dark anymore. The ones with the flames painted on don't seem to work any better than the plan ones

but sadly the E bay good ones all have flames as well it appears.

T1 Terry

Post by **7circle** » Mon, 22 Nov 2010, 15:30

Is this why they invented welding bays so the flash from another welder nearby won't turn your eye piece black.

Get my tow bar fitted to day, so all those ideas for trailer mods will need consideration with a welder.

Thanks for explainations.

7©

Post by **polo-ev** » Mon, 22 Nov 2010, 16:46

Have a close look at your helmet. You will probably find a couple of button cells that can be replaced.
My helmet (a 3M SpeedGlas) started doing the same thing. Would not darken when welding but would darken out in the sun. Leaving it in the sun made it work properly for a little while.
Replaced the batteries & now my helmet works just the way it should again.

Post by **Electrocycle** » Tue, 23 Nov 2010, 04:12

I've found that the cheap masks are not much good for MIG or stick welding, but are fine for TIG (with HF start)
As soon as the HF start kicks in the mask darkens - before the arc has even started, so it's pretty reliable.

Using a cheap one for arc or MIG is definitely not a nice experience!