Now that I am plotting the purchase of a decent TIG and will be able to mate more than just mild steel whenever I feel like it... what, if any breathing protection will I be needing?
For the tiny amount of stainless I've had to weld with a MIG thus far I've just left the garage door open and tried not to breathe the smoke but sitting at the bench with my face buried in plume of chromium smoke seems like a bad idea.
I hear that if you're welding galvanized steel and you don't remove the zinc coating and weld it, you'll regret it!
1988RedT2 wrote: I hear that if you're welding galvanized steel and you don't remove the zinc coating and weld it, you'll regret it!
It will make you as sick as a dog.
and dont prep with Brakleen.
Toyman01 wrote:1988RedT2 wrote: I hear that if you're welding galvanized steel and you don't remove the zinc coating and weld it, you'll regret it!It will make you as sick as a dog.
muriatic acid will remove galvanized, zinc and cadmium coatings, use outdoors
read my post in tech tips
The people I know who care tend to wear a proper respirator inside their welding helmet. I generally work w/ the garage door open and on mild steel, but were I to have a lot of CrMo to do w/ TIG I'd filter up for sure.
And, of course, use acetone for final wipe, not chlorinated brake cleaner, and if you're going to MIG galvanized steel in a hurry and not clean it off, respirator for sure.
slightly on topic slightly off topic.
what is a good cleaner for metal prior to welding? is acetone sufficient and will it disperse fast enough to not be harmful?
Use scotch brite first then wipe it with acetone, but lacquer thinner will work but let the metal dry before you start to weld.
I have only had problems with welding coated or plated metals such as cad coated steel, aluminum coated exhaust tubing or zinc coated steels. I have welded stainless and CrMoly and never has an issue.
I have looked into the stainless fumes thing, as >90% of what I weld is 304. Probably >95% is 304 or 308. Anyway, from my non-exhaustive research on real medical sites, not teh googles, I could find no conclusive studies showing that welding stainless steel was bad for you. Remember that stainless is nickle, chrome and iron.
Dr. Hess wrote: I have looked into the stainless fumes thing, as >90% of what I weld is 304. Probably >95% is 304 or 308. Anyway, from my non-exhaustive research on real medical sites, not teh googles, I could find no conclusive studies showing that welding stainless steel was bad for you. Remember that stainless is nickle, chrome and iron.
Good to know... the only one there that worries me is the chrome. Chrome of the hexavalent chromium kind is really bad for you - I know they use it to make the stuff but not whether it is present in the finished product or the fume.
NIOSH considers metal fumes from welding a potential carcinogen and does have a recommended daily exposure limit (link below) . how the hobbyist can quantify that limit I'm not sure. Be sure and clean all the paint, coatings etc from your work before you weld - not all of the toxins are in the metal. http://www.osha.gov/SLTC/healthguidelines/weldingfumes/recognition.html
Welding most metals creates a gas called hexavalent chromium which is one of the nastiest things you can possibly inhale in your average shop/garage.
The usual source for hex/chro is the consumables, especially if you're doing SMAW (arc or stick) welding or MIG welding using flux-core wire. It's pretty hard to avoid creating hex/chro when dealing with the steel family of metals (even when using other welding processes), so do yourself a favor and pick up a mask/respirator/filter device.
If you look at the OSHA standards for hex/chro in the air, the allowable amounts are VERY low (compared to other gasses in a fabrication environment) because it is just THAT nasty. Luckily it doesn't stay nasty for long before bonding to other elements in the air and becoming less volatile, but it is usually volatile long enough to make it from the weld to your nose.
Always do everything you can do vent your work space and filter the air you're breathing.
(my welding and metals fabrication instructor was really picky about safety)
If you don't want to mess with acids to prep the area you can always use a bench grinder with the wire wheel but you will still want some sort of real ventilation device.
jimbbski wrote: I have only had problems with welding coated or plated metals such as cad coated steel, aluminum coated exhaust tubing or zinc coated steels.
I saw Jesse (the fab/ welding goddess) from Xtreme4X4 welding a cad plated bolt for a stud type mount... complete w/ the white feathers floating in the air and white residue on the weld right on the show. NO, no, no. you don't wanna breathe that, it's toxic.... if you see the white it's too late, you gotta dose. I contacted their website re: using acid to strip cad, zinc, galv. etc for weld prep. After repeated email attempts Ian finally gave it a spot on tech tips.... so it's got Powerblock TV cred!
I dunno why ppl are so reluctant to use muriatic acid. I suspect the welding companies won't go on board as they sell their own Weld Prep (which is just dilute muriatic/ hydrochloric or they're afraid some schmuck will get hurt by their recommendation) Ppl would rather grind or wire brush coatings a cpl feet from their nose (but yea, you got a cad or zinc dose there too) as compared to effortlessly removing coatings w/ no grinding in a controlled area (preferably outdoors) but otherwise well ventilated.... and def step away from the acid while it does it's work, it's nasty. It'll strip aluma-coat exhaust and rust effortlessly too.
The first time I used my cheap stick welder (first welding I ever did) I woke up the next morning with what felt like a massive hangover. The guy at the local welding shop sold me a box of face masks. Here's the manufacturer's description:
R95 protection against both oil and non-oil based particulate aerosols. Added carbon layer helps filter out nuisance levels of ozone/organic vapors.
This mask helps (no more hangovers), but how do I know its true effectiveness against all the nasty stuff?
Dr. Hess wrote: I have looked into the stainless fumes thing, as >90% of what I weld is 304. Probably >95% is 304 or 308. Anyway, from my non-exhaustive research on real medical sites, not teh googles, I could find no conclusive studies showing that welding stainless steel was bad for you. Remember that stainless is nickle, chrome and iron.
Hess,
If you want to do some more non-exhaustive reading on welding fumes, NIOSH (I think) and EPA both have some studies on them. Look up shipbuilding. That's where they both did the various studies. EPA under the NESHAP, and I don't remember the NIOSH studies, but it's probably the same or similar.
Yeah, we have to get waivers for the Chrome inside a stainless bolt.....
FT, having been around ships and shipyards, I know how dangerous both can be. Specifically, both were full of asbestos, especially the rust buckets I used to sail on. General welding fumes, such as SMAW and certainly anything anywhere near any zinc, are not good for you. When I started my Locost chassis, all 304, was when I dug into specifically looking at stainless welding, with inert gas even and not with SMAW, and that's where I didn't really find anything that was ZOMG WE'LL ALL GET KILLED. While I'm sure that not breathing fumes from any welding is certainly better for you than breathing fumes from welding stainless, the amount of fumes involved is not going to hurt us amateur welders.
I'll see if I can dig up the shipbuilding studies.
And here's a pic of some of my 304 work:
Toyman01 wrote:1988RedT2 wrote: I hear that if you're welding galvanized steel and you don't remove the zinc coating and weld it, you'll regret it!It will make you as sick as a dog.
A glass of whole milk helps with the nausea/headache.
I weld for a living, both MIG and TIG, currently doing all stainless steel, and not too long ago did a big galvanized job. Never used a respirator or any breathing apparatus and did not get any nausea or any other negative effects. Ditto for the people I work with. You do need to grind off galvanizing before welding, but that's it. Keep your face out of the fumes, and having a fan moving some air is not a bad thing. The lower your ceilings are, the more caution I would use.
I have tried to find a good answer for all this and always come up with conflicting reports. :(
I put a 12" exhaust fan about 4' above my welding table. I've been considering adding ducting that I can position over or near what I'm welding because I do still get fumes coming in the bottom of my welding helmet before they can make their way up to the fan. Overkill? Maybe, but better safe than sorry.
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