Is looking at welding really dangerous?

[Stranger_On_A_Train]

@David Simmons

It is true of lasers which do emit a beam of parallel rays. The only thing that dims them with distance is scattering.

Not quite true; even a beam produced by a laser will diverge due to diffraction.

Stranger

[David_Simmons]

@Stranger On A Train

Not quite true; even a beam produced by a laser will diverge due to diffraction.

Stranger

:smack: I keep forgetting diffraction.

All analogs break down. There’s just no way to get it preciesly right.

[Mesquite-oh]

@hlanelee

Once upon a time, when I spent a summer commercial fishing, I sat on the dock with a six pack and was fastinated watching the reflection of an arc welder in the water. Someone was welding on the rigging of a shrimpboat and I just could not take my eyes off of the perfect reflection of the arc in the river. That night I felt like I had acid thrown in my eyes because the burning sensation was so intense.

My father said that he was working in a room that had glossy paint and got his eyes fried by someone who was welding in another part of the room. He said that he never actually looked at the light.

[matt]

@Fridgemagnet

I too have learned the hard way about UV burns from electrical welding, in particular the time some goggles with factor-11 glass protected my eyes wonderfully, but left the rest of my face to burn.)

OUCH!

I started out looking at the arc through one of the glass panels from a welding mask, before someone pointed out that was a good way to leave an unburnt rectangle on my face at the end of the day. I just wanted to see what the guy was actually doing.

@Fridgemagnet

The light spectrum in electrical welding arcs contains a lot of nasty UV-B and even nastier UV-C, and doesn’t even give a good suntan, just radiation burns…

I did wonder about that. Red and flakey, not a hint of a tan.

@David Simmons

If you look closely you will notice that besides the mask arc welders keep their sleeves rolled down and their shirt collars buttoned up.

In Aberdeen at least, they also wear baseball caps back-to-front with the weldling mask. This isn’t to protect against UV, it’s to stop sparks from the angle grinder going down your neck as you grind back between weld runs…

[Fridgemagnet]

Sorry, did I say spotlights - I meant searchlights; i.e. a reasonably parallel beam that picks out enemy aircraft or stage performers, not the things that illuminate kitchens. Thinking about it, I meant spotlights after all, just the theartical not domestic variety. And searchlights. The beams from lighthouses won’t obey the inverse-square law either…

Most of the beam-spreading in a laser is from divergence, and will happen even in a vacuum with no scattering particles. It’s due to non-idealities in the optics, and laser diodes are notorious for it, their slightly squashed elliptical beam really not helping. Beam-shaper optics are useful, or a gas laser with a circular beam. Even so, one old helium-neon laser I was playing with would have an initial beam of about 1mm diameter, which would produce a 3cm spot at a distance of 50 metres.

Another lesson I’ve learned the hard way: A faceful of sparks from an angle grinder may be survivable, but it leaves little permanent pock marks in the lens coating of one’s glasses. Also tiny bits of metal melt themselves into the surface of the glass in my garage window, and need periodically to be scraped out. Again, leaving little craters. Those tiny sparks must be bastard hot.

[danceswithcats]

@chriscya

My father said that he was working in a room that had glossy paint and got his eyes fried by someone who was welding in another part of the room. He said that he never actually looked at the light.

One of my employees ended up in the hospital, suffering from what many would call a case of snow blindness. He had been working as a panel setter/rigger, adjacent to the panel welder while erecting a modular bank vault. Time exposure to the arc flash, even though indirect, put the young man in the ER.