welding mask for laser safety?

[twenglish1]

Just a thought, I think I already know the answer, but how well would a welding mask of say shade 10 or 11 work for laser safety? Specifically a 445nm 1watt

 

[oahu99]

NONONONO!
This question comes up way to often.
But proper safety glasses like Eagle pair or laser shields!

 

[twenglish1]

That was exactly what I thought, I think welding masks are only designed to block uv, and darkness is just so you can see what you are doing, cause auto darkening masks have a uv shield built in so you are still protected if it fails to darken

 

[hakzaw1]

yeah

One thing that can happen is-- the dark lens causes your eyes to dialate- which allows eb=even more light to enter your eye and if it is a direct shot your eye's lens will magnify the laser hundreds of times- some say 'anything is better than nothing' and that is not alwasy true- get some cheapies ASAP - save up for better then use your cheapies for your guests - but let them know they STILL need to stay out of the 'danger zones'--

hope this helps hak

 

[upaa27]

I have started using something that looks really similar to a welder's mask and when I lpmed how much was going through I got 7mw peak out of 2844mw!

 

[twenglish1]

I purchased a pair of cheapies on eBay and I will be buying a higher end pair

 

[KrowBar]

An 11 shade is something like OD 4.3. But you don't know how that breaks up spectrally. Since welding shades are primarily for blocking UV, they tend to have low transmittance at low wavelengths, but might be more transparent at visible wavelengths - but they are overall still very boadband (neutral density) compared to laser safety goggles. While you might be able to find a transmittance plot for the particular shade you are considering, and could therefore probably determine if it will be acceptable for 445nm, you will still have the problem of being unable to see anything at all which could make for a dangerous situation. That being said, I have always thought that being able to see everything except for a potentially blinding laser beam lends itself to some possibly dangerous situations as well. If you verify acceptable transmittance of a welding shade for the wavelength of interest, I don't see any problem using the welders shade to do something like observe a dot as you try to focus.

 

[hakzaw1]

I purchased a pair of cheapies on eBay and I will be buying a higher end pair

good plan-

what a post whore you are!!
4 years and one month since you joined and only 31 posts--lol

J/K--
& even tho this has been asked before... its a common belief that other kinds eye protection is safe for all lasers-- not always true.
so great thread--+5

 

[Sigurthr]

Shade 14 is good for most high and low wavelengths at under 2W of power but you won't be able to see what you're doing. Welding lenses tend to pass green and yellow more than other colors too. I never advocate their use simply because they are impractical.

Also who are you guys learning that they mostly block UV from? That is entirely false. Yes they block UV but they mostly block IR and NIR, either in terms of bandwidth blocked or intensity blocked! Welding arcs and weld pools are black body radiators and UV is the smallest fraction of their output. (I was a precision TIG welder for many years).

Scientifically though if you confirm the transmittance with an LPM then you can make your own call on what eyewear to use.

 

[KrowBar]

Also who are you guys learning that they mostly block UV from?

Look at a transmittance plot for your shade 12+. Yeah you have a lot of IR, but the IR aint what sunburns your arms when you wear them gloves that barely cover your wrists. Your shade 5 for gas welding might be designed with mainly IR/NIR in mind, but just because most of the intensity from an arc is in the IR range, that doesn't equate to what the shades block. Photokeratitis avoidance is one of the main things that the higher shade filters for arc welding are designed for. The Cornea absorbs UV like a sharpie colored match head, so it doesn't cause the retina damage that IR does, but it's all sorts of painful when it gets inflamed.

That was exactly what I thought, I think welding masks are only designed to block uv

The key thing making this guess incorrect is the word only. It is IR that causes retinal burns, so they better be blocking that - especially since as Sigurthr pointed out, most of the energy in a welding arc is IR.

 

[Sigurthr]

It depends on how you define burns. UV causes photochemical damage that leads to cell death. IR causes thermal damage (burns). The eyes are sensitive to both forms of damage (at different locations). Also, FAR IR isn't typically plotted on transmittance charts because just about everything blocks it.

My point was that arc-blindness isn't caused by UV, but retinal damage from visible and NIR/IR wavelengths.

I've had arc eye a fair number of times, it is most certainly unpleasant. I describe it as having your eyelids held open and having a mixture of salt and sand poured into them, and then trying to wash your eyes out with vinegar and onion juice.

 

[twenglish1]

Arc eye is caused by uv burns to the cornea, that is why it is also called snow blindness, happens to skiers and snowboarders from the suns reflection off the snow

 

[Sigurthr]

Arc-eye/snow-blindness (photokeratitis - cornea damage) is not the same as arc-blindness (which is an extended form of flash-blindness (retinal damage).

 

[The Lightning Stalker]

Also who are you guys learning that they mostly block UV from? That is entirely false. Yes they block UV but they mostly block IR and NIR, either in terms of bandwidth blocked or intensity blocked! Welding arcs and weld pools are black body radiators and UV is the smallest fraction of their output. (I was a precision TIG welder for many years).

Nitrogen has some strong UV lines (think TEA laser).
A mask will often have a polycarbonate lens to block
any UV that is not blocked by the shade filter. Most
shade filters are now made from polycarbonate
themselves now though instead of glass, so this has
become less of an issue. The auto-darkening are
different though. I think they still have polycarbonate
or other UV filtering layers inside though.

 

[LSRFAQ]

The Auto-darkening welder's mask have a LCD shutter in them with a IR/UV adsorber. Without a prior flash to trigger them, Auto-darkening would be useless as safety goggles with most lasers.

The coated polycarbonate outer will adsorb some Near IR, Far IR and UV on a Auto-darkening mask, but would be useless for visible and high power near IR as there is no flash to drive the solar cell that drives the LCD driver circuit.

PEASE DO NOT USE AUTO_DARKENING ANYTHING as a laser safety goggle. Including the "Transitions" sun glasses with the silver activated lead glass that turns dark with UV. The beam flies much, much faster then the slow chemical reaction activates.

Thick polycarbonate is OK with UV lasers if they are full wraparound and the laser is CW ONLY. Useful with low power, ie less then a few hundred mW. I did lab tests with CW 335 and 354 nm Ion lasers to a half watt and found OD6 at best, across three different manufacturers.

They did burn or melt with beams larger then 350 mW in prolonged exposure.

Steve