Arc Flash Welding

Arc Flash- Use The Right Lens And Stay Safe

An Arc Flash in welding is when your eyes get blinded by the welding arc. This causes damage to your eyes over time and should be taken seriously. There are multiple reasons for getting arc flashed, and some flashes are more severe than others. This article will give you some insight into this topic, and what to avoid.

Arc Flash Welding
Don’t Get burned! : Public Domain Pictures

Types of Arc Flashes

The worst type of arc flash is when your welding hood isn’t over your face. This could happen because a coworker is welding next to you and you didn’t see it coming. It can also happen because humans make stupid mistakes like forgetting to flip their welding hoods down. I have done this multiple times.

After being exposed to a welding arc with unprotected eyes, you may see some blue or black spots in your vision field for a couple of minutes. This all depends on how much amperage was used during the weld, and also how long you were exposed to the flash. Symptoms usually go away in a few minutes. However, multiple exposures over a lifetime is comparable to staring at the sun every so often!

Another common reason welders get arc flashed is because their lens shade isn’t dark enough. These are more mild exposures and are less noticeable throughout the course of a workday. If you continue to use an inadequate lens shade for your work, you will definitely see the effects over time. These effects include dry eyes at the end of the day – all the way to burnt eyes where you will need to see a qualified medical professional. You may even notice a sunburn on your face later that evening.

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Lens Shades

Lens shades 9, 10 and 11 are the most common for welders these days. In my welding routine, I rarely go lighter than a shade 9, and I only use a shade 12 for very high amperage/voltage applications. This also comes down to each individuals eyes and their tolerance for bright light. Some welders can get away with a shade 9, while others will want a shade 10 for the same project. Very heavy industrial applications may require a shade 13 or 14. These projects are usually high amperage stick welding or high voltage flux core MIG welding.

Auto darkening welding hoods are the go to welding hoods these days. They allow you to see your work before you strike an arc, and then immediately darken once you start welding. These hoods have gotten more affordable and they have settings and dials where you can change your shades as much as you please.

Some classic hoods and lenses are referred to as fixed shade lenses. These lenses are always dark and stay in their respective shades at all times. If you go this route, you’ll want a small assortment of different lens shades. These are harder for beginners to use because once you flip your hood down, you can’t see anything. You must know where your hands are positioned before you flip your hood, or else your weld won’t start where you expected it to.


There is some debate as to whether fixed shade lenses are safer than auto darkening lenses. Do they lower the risk of arc flash? Although auto darkening lenses switch in a small fraction of a second, your eyes do get exposed to the arc each time. Add those split seconds up over a lifetime, and you may want to see your eye doctor. Fixed shade lenses allow the welder to never get their eyes exposed to the uv rays for any fraction of a second. This will ensure that your eyes never get damaged by the UV rays from welding. I was so used to the fixed shade lens by the time I took my AWS certification tests, that it didn’t bother me to run a plate test with a fixed shade. I also felt safer from an optical standpoint.

If you’re a beginner just starting out, I would highly recommend a shade 10 lens. This is good for Stick welding between 70-125 amps (3/32″ and 1/8″ rod). It can also be used for MIG welding between 17-22 volts, and TIG welding between 40-125 amps. This will keep you safe from an arc flash, and you can always bump up to a shade 11 or 12 for heavier duty projects.

Many affordable welding hoods have a dial between a shade 8 through a shade 12. You can play around with what works for you without it looking too bright. You won’t have to buy multiple lenses for different projects. Remember, if your weld looks too bright, your eyes might be in danger.


In closing, arc flash shouldn’t be something to worry about if you’re being careful and using the right protective equipment. Welding hoods are important but so is covering the rest of your body!

Thanks for reading.


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