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Welding galv respiratory protection

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I occasionally need to weld up galv and stainless stuff, which really isn't good for the old lungs. My usual setup with a fan blowing behind me works, but I really ought to find something better. I did a little research and found a promising set of 3M products recommended here and there, but I think they're either discontinued/superceded or were for the American market. Looking for a slimline half face mask that will fit under a welding helmet with appropriate filters. Could be disposable or reusable with changeable filters. 

I found the literature pretty confusing - is it a gas, a particulate or something else that needs filtering? - so I'm none the wiser for looking!

Many thanks! 

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Stainless isn't an issue to weld. Its the Galv. I think its a gas that's given off, so you'll need an air fed mask.

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Generally you'd want to grind the zinc back to clean steel before welding anyway so it shouldn't be a big issue, welding straight onto the zinc is poor practice like welding through paint rather than grinding it clean.

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I guess my technique of just holding my breath is probably not right?

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Thanks gents. I think I'm one of those unlucky people who have a worse reaction than most. A good whiff of galv vapour and I'll definitely have a sore throat or worse. It's those occasions where you can't get to the back of something to grind it off - that kinda thing that I've had trouble with in the past. 

I've ordered a 3M 7500 with various filters for vapour and particulates depending on what I'm doing. 2183 and 6075 were recommended on the 3M chart, so I'll see how I get on. Either way, a decent setup will be welcome for many jobs, so a worthy investment, I think. 

The stainless is an interesting one - I thought it was harmless, but during my digging around I found a paper or two suggesting it gives off chromium something-or-other, which didn't sound great in a less immediate fashion than zinc. I'll dig it out. 

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While we're on the subject I've seen a few mentions of brake cleaner reacting badly to welding, if people use that to clean things before welding.

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Yep..  chlorinated stuff is bad, produces phosgene gas I believe... Instant death or something, way more harmful than zinc.

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Do NOT EVER use brake cleaner to clean parts for welding.

Quote

The deadly chemical was probably "phosgene".

http://en.wikipedia.org/wiki/Phosgene

The intense UV radiation from arc welding can cause a chemical reaction with some chlorinated chemicals (such as some spray brake cleaners), most likely or commonly containing 1-1-1-trichloroethane

http://en.wikipedia.org/wiki/1,1,1-Trichloroethane

or possibly dichloromethane

http://en.wikipedia.org/wiki/Dichloromethane

The argon gas really has nothing to do with phosgene formation via UV radiation on the chlorinated solvent, and neither does heat (temperatures hotter than ~200C actually cause phosgene to break down into carbon monoxide and chlorine, neither of which are good for the body and which are both toxic but not to the degree that phosgene is).

The chlorinated brake-cleaner sprays around here are being phased out and now they mostly seem to be other solvent or solvent blends (most common that I now see and use is pretty much acetone in a spray can, works OK but not quite as well as the tri-chlor solvent).

You still have to be careful with ANY cleaning solvent, as most are still flammable and/or dangerous.

Ventilation and being aware of the dangers/risks from the solvent(s) you are using is impostant. Read the label!!!!

If using solvents and welding, make sure that ALL of the solvent has evaporated before you weld.

http://weldingweb.com/showthread.php?182941-DANGER-using-BrakeCleaner-to-clean-your-Parts

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There is un-chlorinated brake cleaner widely available, which is perfectly safe to use.

In fact I think the plan is that the chlorinated stuff will be phased out entirely.

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Thanks for the tip on the brake cleaner.  That would be all too easily done :blush:

 

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