I was planning to use some galvanized metal (actually roofing flashing) to repair my grill... but a friend mentioned that the heat from the grill might cause fumes to be released (due to the glavanization). Should this be a concern?
I don't recall, but I doubt that it isn't poisonous. Just spraying it onto a surface probably isn't real bad for you, but welding through it (burning it off) can't be good for you. Heck just welding through rust or paint isn't good for you. Just my humble 2 cents.
-- Lynn "I have opposable thumbs, and I'm not scared to use em" Amick
Zinc as metal is not that much toxic, zinc fumes are a problem. The quickest google search will find articles like this one:
"Metal fume fever is an acute, self-limited, flu-like illness developing after inhalation of metal oxides, of which the most common cause is zinc oxide fume generated by working bronze or welding galvanized steel. The symptoms include malaize (discomfort, uneasiness), myalgia (muscle aches), fever, chills, and headache. There may be profound thirst, sweating, and anorexia (loss of appetite). One study indicated there is marked pulmonary (lung) inflammation whether symptoms develop or not. First aid is fresh air and symptomatic treatment, such as acetaminophen."
I actually did a limited self test a few days ago (the piece was small and the zinc coating did not look like zinc) and can confirm that the fumes are bad for you. I did not experience poisonning, but indeed after a few inches of welding fresh air suddently looked like an imperious necessity.
You were not getting metal fume fever after that short bit of welding but you may have been holding your breath as you should have been if not using fume extraction and/or a respirator. You also may have inhaled some of the plume and experienced the same thing (lack of fresh air). You could be alergic to something in the plume. The accounts I heard from professional welders doing zinc got sick toward the end of the day or when they got home. I've never been sick in the least from galvanized welding and I've done lots and lots of it. In all welding including inert gas shielded there is a good amount of poisionous gasses not to mention ozone and UV rays. Smoke from welding is not any different than a camp fire or a house burning. ALL smoke is poisionous and should be avoided. The fact that you're still here to read this is a testament to the strength of your body to defend itself and react to dangers. A breath or two (maximum) in a house *filled* with smoke causes unconsiousness and death to soon follow. Helium and Argon will kill you in a more subtle way without much warning. So welders soon to learn to hold their breath or use a fan and do it outdoors if possible.
Dittto. Welding galvanized is possible. People do it all the time. Now, if you are going to weld if ALL day, and you have to keep your head in the plume, you will probably have a reaction. Drinking milk may help wash some of it out of your throat, but I don't think that helps any of the other symptoms, since it gets down into the lungs. When you weld galvanized, notice the white stringy stuff that floats away, and sticks to the metal near the arc. That is the stuff that is getting to you.
When I weld galvanized, I try to use 6010 to cut through it, and position myself and the work to take advantage of a breeze, an outdoor location, and to be out of the plume myself.
The good news is that it only makes you sick temporarily, it won't kill you.
Zinc volatilizes at about 1600 F., that's the white powder you see. I was told that inhaling the aromatic and particulate matter from burning zinc cause your body to lose a great deal of calcium rapidly, thus cause the headaches and stomach flu-like symptoms. We always ate a couple of oyster shell calcium tablets with a pint of milk prior to any cutting or welding.
I said upfront that I have not be poisoned. I did not hold my breath, since I did not realise at first that there was zinc, so that is also excluded. OTOH, after a short time, I realised that my lungs where not feeling "comfortable" (I can't really explain it better), so I went outside and got some fresh air. This was the extend of it, and I will avoid zinc from now on, or try to do it in a well ventilated area if no other solution can be found.
Pleased don't be offended, but I think that this attitude may actually be dangerous. Smoke from welding, wood fire smoke, a house filled with smoke or helium are very different dangers and need a different response. For example, one should avoid breathing smoke while breathing helium is not dangerous as long as you have enough oxygen to go with it. I think that the best safety measure is education: one needs to understand why and how a particular thing is dangerous to find the best response against it according to the particular circumstances.
*Then* the solution is usually simple common sense, like the one you cited:
which is an obvious and simple solution, *once* you know what the danger is.
The problem with that is at least with smoke you get a "knock on the door" warning and with welding gasses there may not be any warning at all. Maybe you haven't seen the postings at welding suppliers of the deaths that happen with argon in enclosed places. One such account I read, not only killed the welder but his buddy who went in to rescue him when he passed out. The article didn't state if the argon tank had been leaking but I suspect it was for enough time to deplete the area of oxygen. Rare, yes and I'm glad it is.
Really the point I am making to all of us is that zinc oxide in the welding plume may not be the worst thing there and it may be a guardian angel reminding you not to breathe any of the poisons *normally found* in the SMAW or FCAW plume. That's not to say that MIG or TIG are any better but I consider the flux types in a category of their own.
Legal disclaimer: Of course this is the unique way I see it and I'm sure if you agree with any of it you will take the pieces you like from this and other opinions and form your own.