I have heard that you cant weld EMT because its galvanized and the fumes will kill you. So that being the case, whats the best way to get a nice tight radius to mould 2 adjacent body panels together. I was going to take some 3/4 inch EMT and slice it to make a quarter pipe type curve. Do you think its OK to weld it outside, maybe with a fan blowing the fumes away?
welding galvanized will not kill you it will make you sick if you breath the fumes in. so make sure you have your hood down. or you could weld it outside. if its only a few welds it shouldnt get you sick even if you do breath it in.. an old welders trick is to drink a tall gl*** of whole milk before you weld galvanized the thought is that the milk will line your stomach and not let the toxins or what have you seem past your stomach into your body usually you get sick to your stomach when inhaling alot of galvanized fumes... my throat usually hurts and is itchy after breathing alot in..... just be cautious not to breath in too much
iwas welding galvanized all day yesterday.. i just try not to breath too much when i am in the middle of it and when im done i walk a way for a minute or 2... welding outside you shouldnt have a prob at all. just in those tiny shops and confined spaces
Easy enough to grind the Zinc off the outside, but don't forget there is Zinc on the inside too. Don't breathe the smoke, and it will be ok.
First grind it clean of the galvanized material where you will weld it, be sure it is well ventilated. There is a bright green gas that comes off of burning galvanizing this is the bad stuff. If you inhale this you will get a real sweet taste in the back of your throat,this is not good. It won't kill you right away but will attack your bone marrow. I worked in shop where we had to weld it and they would pay welders $0.50 aday extra for milk for your bones. I don't think this would fly in 08 but back in the 60's the union thought it was ok. I think if you doit outside and grind it good you will be ok.
Instead of grinding it off, read up on electrolysis / electroplating using a 12V battery charger. If you do it right, all the zinc will be eaten off the tube inside and out.
Researching this a few years ago I never came across any link between zinc fumes and bone marrow damage, welders flu is the worst I could find which is a brief period of flu like symptoms after initial exposure but then immunity. It's difficult to remove completely the way it smears with grinders and sanders, for lack of better info I'm still more concerned with it contaminating the weld than me.
Do you have access to a brake? If you do,mount a piece of tubing the radius that you want to the foot of the brake.Re-adjust the depth of the foot in relation to the bending leg and have fun.
this is the wrong forum to get medical advice, research poisons, metal and other through other venues breathing enough fumes from burning zinc will definately kill you but for what you describe if you take a few simple precautions you should be fine.
I don't like welding galvanised stuff but have to do it some times. I wear one of these respirators with 2097 filters. They don't cost much and I believe they help.
What are you making? Is this a 90 degree outside corner weld, or a simple **** weld? Not sure why you want to use that particular tubing instead of something else. If you want a nice radius on a corner, a hammer-form is a great way to go. John www.ghiaspecialties.com
Use a piece of 'black iron' gas pipe, 1/2" would probably be same as 3/4"emt. The emt is also a poor choice in that it dosn't have enought m*** if you are going to hammer against it. Zinc/Cadmiun poisoning is bad stuff i had collapsed lung, recovered ok but i get just a whiff of it now and my body goes into shock.
My brother is a blacksmith and he suggested eating the zinc off with acid outside. this will remove the galvanization, and subsiquent fumes. Hydrochloric acid should work fine.
I was told that it would eat the enamel off your teeth. I always ground it off and still have my pearly whites, must have been an "old welders tale". The residual coating made the arc a neat green glow though. Bob
Try Muriatic acid available at hardware stores, (cheap) Do it outside. I think it the same as Hydrochloric? Ago
Muratic Acid will strip the zinc off the tubing as well, you can get it at a pool supply or hardware store. Rinse it off after dipping it and let dry, should be ready to go. Dont let the acid touch you though. Ago beat me to it sorry to repeat that
The simple way I've found to remove galvanization is vinigar. Found the info on one of those rennisance web sites where they build armor. Just emerse the emt in a vinigar bath for a couple of days and no more galvy. Just finished rod holders for my tig and this worked great. Also no caustic acids to dispose of. Good luck.
Why bother with the EMT? The "real" question was (as I read into it) was "he wanted to make a radiused corner where 2 parts of panels met". Am I correct in this? If so, if the joint is going to be straight, just work each end of the panels into a half radius, with a hammer and dolly. The dolly needs to be the correct radius that you desire (1/2 or 3/4, I would suppose?) Make each end of the panel 1/2 of the radius, so when you wled them together, the radius helps keep the warpage contained. And a little hammer and dolly work will finish it up. Now, if the joint is curved, you can still hammer and dolly it, it's just a bit harder, or you can use your EMT, bend it into the curvature you want, fill it with sand, very tightly, and cap the ends. Then you can clamp or tack weld it into position, and hammer the sheet metal edges over it, to get the desired shape. do this to both edges, trim the edges to a **** weld, and remove the EMT, and weld'er up. You might get away with not doing the sand-fill, but it will help to keep the EMT from collapsing, if you aren't as proficient with a hammer. If you do it as you proposed, with a piece of EMT, you'll have 2 weld joints, instead of one, both will be adjacent to the flatter part of the panels (I ***ume), so you'll have more warpage problems, difficulty in hammer and dollying them out, the galvo welding issue, and just overall, more trouble IMHO.
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