Saturday, January 15, 2011

welding helmet renewal

I learned to weld (SMAW - aka Arc welding, aka "Stick welding") with a standard CIG "rockhide" full face helmet. You had to flip the helmet up and down to see whenever the arc wasn't running. Better than the handheld mask I used a few years later, but still painful to use compared to the newer "speed glass" style auto-tinting helmets. It's so much easier to weld when I can see the tip of the rod moving up to the point of the weld, instead of losing sight of it due to flipping the filter down

I bought a cheap helmet and used it for several years, and eventually it stopped working. Being the tinkerer that I am, I opened up the main unit and discovered a few things...

The helmet has a solar cell on it, and was advertised as never needing batteries since it charged from the sun. The batteries inside were 2 silver oxide non-chargeable button cells. My guess was that the solar cell reduced load on the batteries, but was never able to charge them. (Silver oxide batteries aren't rechargeable)

The other finding when I opened up the unit was that the nominal 6VDC across the 2 batteries was only 2.8VDC... I can hardly complain since they lasted seven years.




The rest of the circuitry is under the white "potting" used to protect the circuitry - I never disturbed that, just accessed the silver terminals which used to be spot welded to the original batteries.

Armed with that finding, I quickly fashioned up a 6VDC supply and connected it to the original battery leads (with the old battery removed) and tested the helmet - it worked.



The photo above shows the hole drilled through the back panel of the glass unit, and some flexible Cat5 cable led through for accessing the power terminals of the electronics.

A more permanent solution was made up...
The battery holders are from some cheap solar garden lights the dog broke
The cable is some flexible Cat5 patch cable
A number of holes were drilled in the helmet to affix the battery holders, and cabling.
All holes were then sealed over with some hot-melt glue, and painted over to block the UV from the welding operations.






Problems found with this solution:
Firstly the weight of 4 AA batteries sitting at my mouth level caused the front of the helmet to always hang down - rendering the friction locks at the headband useless - I ended up resorting to a short length of cord which runs from the top of the helmet to the back of the headband to stop that
The other issue I found was the attempt I made to have the power "switched", and removable - the 2 automotive crimps - frankly they proved more trouble than benefit. I'll cut them out and replace them with a soldered joint.


What else do I know about these units?
They don't like being dropped in quench buckets full of water
They don't like sweat dripping into them - day after stinking hot day
They can be replaced for around $30 via ebay (6shopriver is an example seller - no connection)

I don't consider the repairs I made to be a waste of time, they bought me some time so I could finish the job until I could replace the failing helmet. I will fully repair this helmet if possible and keep it as a back up.

1 comment:

  1. Welding helmets add protection to the professional and amateur welder of today. When you strike an ark the lens inside the helmet automatically adjusts to a shade 9 up to a shade 13. Some may adjust more than that, depending on the Welding Helmet you purchase.

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