Welder’s glass #13 (or something like that) can be used to directly view the sun, so I learned with eclipse preparation. What is it about welding that requires such powerful filtering? How can they see what they’re doing? I got filter glasses for the eclipse and you can’t see shit except for the sun.
You can see the sun with eclipse glasses on; likewise, you can see the arc and anything immediately lit up by the arc with a welding mask on. It’s that bright, and it throws off UV rays and will sunburn you if you’re not wearing appropriate gear.
Being able to line up your weld with the mask up, then coordinate closing your eyes, flipping the mask down with a heavy nod, and starting the arc all at the same time takes practice. Or you can get an auto-darkening welding mask, which is like an auto-dimming rearview mirror turned up to 12.
I once worked in a factory where they did electric argon welding on stainless steel. The welding area was screened off, but I walked past one day and glanced through a gap. The light literally hurt; I was seeing spots for hours after and that was from an exposure of less than a second.
That light is BRIGHT.
Arc light is one of the brightest and most compact light sources man has ever invented. Carbon Arcs were used as searchlight light sources. Metal arcs also generate a lot of UV.
While viewing the eclipse, one guy had a couple of welding helmets and pieces of glass (in addition to his scopes.) I asked him if he’d done any welding, and in the ensuing discussion he observed that he had given himself "sun"burn while arc welding.
I have great respect for welders. They work with energies that can kill or blind you. Heavy metal things that can crush you. At heights than are lethal to fall from. In the middle of toxic gases that can give you cancer. Stuff so hot that “Third degree” is an understatement. Sparks. Heart stopping levels of electricity. Heat exhaustion. They generally are paid well but not nearly enough. I wouldn’t do it for any amount of money.
Some checking …
The Sun’s “surface” is around 5,500ºC … arc welding runs between 3,000ºC and 24,000ºC {Cite} … and lightning is between 25,000ºC and 54,000ºC … light emission is directly proportional to temperature (sort of) …
It’s a skill to be able to line up our weld, drop our hood in place and start the weld … once the welding begins there’s plenty of light to see what we’re doing even with #13 glass …
Welding glass, regardless of shade number, should filter out 100% of the UV and IR spectrum.
What is left is visible light, with a higher shade number offering a darker lens and thus more protection.
Some high amperage carbon arc welding does provide light intense enough to require shade #14, as dark a shade needed to safely view the sun. But most welding processes do not provide such intense light. Routine stick welding is safely handled with only shade #10.
Mere brazing might be done with only shade #5 goggles which are light enough to seem like a dark pair of sun glasses.
Regardless of process, you need to have a dark enough lens to protect the eyes but not so dark that you cannot see the weld puddle and what you are doing. And you want sufficient protection for your hands and arms to prevent burns, both thermal from spatter and radiant “sunburn” from the UV and IR emitted from the arc.
You need darker filters for welding than viewing the sun. The sun won’t even trigger my auto-darkening welding helmet, i used a helmet with a regular filter to see the eclipse. Noted above, welding arcs can be insanely hot, and inches from your eyes.
You even need to watch what you are wearing, welding arc can easily penetrate clothing if it is not UV rated. Many a welder has burnt the fabric pattern onto his chest. I was once doing some welding on a race car roll cage and needed to get my head right up to the ceiling. So I had a clever idea. I wore welding goggles and my balaclava, which is the fire proof hood that you wear under the helmet when racing.
Alas, it may have been fire proof, but it wasn’t a tight enough weave. The criss-cross pattern was fried onto my forehead and hurt like Hell for a long time.
One area many beginning welders overlook is the neck. They have on the leather coat but don’t button the neck all the way up. The arc shines under the helmet lower edge right onto your neck.
As for being able to see when you are welding, you can readily see the area around the welding zone. My self dimming helmet is fully adjustable for the darkness, you dial it down until you can see properly. Otherwise, use whatever filter is needed for the level of welding you are doing. Light gauge TIG needs only a 9-10, while higher amperage stick welding might need a 12.
Dennis
It’s much worse than directly proportional. The total power of light emitted is proportional to the temperature to the fourth power. So for a light source four times hotter than the Sun, the power per area will be 256 times greater.
I used to work in a plant that manufactured trailers doing air line assembly, ‘brakes and bags’, and had to do this job under the trailer usually while someone was welding above. I learned a couple things really quickly: 1. Don’t look at the welding (I already knew that though) and 2. Welding berries hurt when they go down your shirt or land in your hair.
Free advice: Never, ever, under any circumstances try to catch anything that a welder tosses to you. Let it hit the floor.
[bangs head against desk really hard] … I guess I low-balled that a little …
And they arc weld under water at great depths as well. Welders are BAMF’s!
My dad was in sheet metal, so he didn’t do any welding but was constantly around welders at the plant. Dad just walked around in his overalls without a shirt underneath, and partially unbuttoned. Because of exposure to welding, his skin is all leathery on his face and in a V pattern down to his nipples - otherwise, he’s pasty white.
My friend saw dad without a shirt once and said “holy crap your dad is melting!”
Back in 1978, I took a machinist/welding class in High School.
As I came out of a booth after a project I discovered that the bottom of my pants were on fire.
There where large tubs about to dip and cool your work, so since I was on fire, I jumped in.
Made from some wet shoes for the day. Excellent lesson.
I have a small arc welder now, and used the hood to glance at our eclipse.
As far as I know, know one was grievously injured in that class. Fun times.
Some years ago I was TIG[sup]*[/sup] welding using a standard (non-autodarkening) helmet. I had to do a bunch of tack welds[sup]**[/sup]. A tack weld being very brief, I simply left my helmet up and closed my eyes for each one. Except I did a bunch, like maybe a hundred, accumulating maybe 30 seconds of exposure. I developed a severe sunburn on my face as a result. It was my impetus for buying an auto-darkening helmet, so that I would never feel tempted to tack-weld without my mask down again.
- TIG = Tungsten Inert Gas welding. Whereas the more common stick welding uses flux-coated filler rods, TIG uses argon as a shield gas. The result is a lot less smoke, and a LOT more UV being sprayed around the area.
** A tack-weld is just a quick blast of current to lightly stick two parts together in the desired configuration so you can come back later and apply a proper weld. Tack welds are a short-cut so you don’t have to clamp your parts: you arrange them, hold them there with one hand, and tack-weld with the other, leaving your welding mask up during the tack weld (because you don’t have a free hand to lower your helmet).
Old cinema projectors used carbon arc too. I worked as a projectionist for a short time in around 1978. Having the rods run out mid-reel was a nightmare. I also did a welding class where we used a carbon arc torch for welding wrought iron.
A college theatre scene shop taught me good. Without having done any welding before, I had to cut some jagged weapons out of steel plate for which I used an acetylene torch. Then spent a couple hours with the arc welder putting hangers on them. Long sleeve, heavy shirt, gloves and mask. I forgot to button the top button of the shirt. I was branded with a bright red triangle on my neck. Kind of cool, but, ouch!