welding zinc coated steel

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Hi, I'd like to weld these 14 ga "L"s with my little lincoln sp-135 (innershield NR-211MP wire).  I think it's a mild steel and it passes the magnet test.It doesn't seem like you  can sand the zinc off like paint.  It just seem like when I sand it, I don't seem to get to the steel.  So can I just weld away or should I sand regardless?Dave
Reply:You can grind the coating off, and your set-up should do fine
Reply:Just don't breathe the resultant fumes.-Heath
Reply:I bought the metal from lowe's and they had a disclaimer that welding zinc coated steel produces toxic fumes, so I'll do it outside with a fan.  Can't run any power tools at midnight, so I practised with a couple of nail plates without prep.  I did a single lap joint and it held together, even after bending it backwards in my vise.  But it wasn't pretty and this is the first touched a welder since, high school ROP.I'll try and hit it with a hard wire brush because I'm dangerous with a grinder -I'll end up eating up the steel and then it'll be too short  This little welder has almost no feedback, vs those giant shop migs where you have to the gun tighter.
Reply:A wire brush won't even come close to doing the job.  If you grind it well, there will still be toxic fumes.  If you don't grind it well, there will be a lot of toxic fumes.  Hold your breath, use a respirator, do it outside, and have a fan.Most hardware stores have mild steel suitable for welding.-Heath
Reply:I've been welding galvanized material since the early seventies.I've found we all have different tolerances to things.  Sorta like the person who dies from lung cancer that was married to the  guy who smoked while the smoker lives into his eighties.The symptoms of galvanize poisoning are similar to bad body flu.  Weakness, body aches, and sickness to one's stomach.  For me it never lasted more than a couple of hours maximum.  However one of my neighbors who had a desk job helped me while I welded up a bird cage for his cockatiels.  He helped me one evening while I was welding it up (six by six by eighteen, that's feet).  He spent three days in bed sicker'n a dog.  He thought he had the flu.In the old days weldors welding galvanized were given all the milk or heavy cream they wanted while welding or in the area.I do it outside or with a fan on if I'm inside.  I also have some 3M face masks that are rated for galvanized smoke.  I use one every year or so.It's nothing but a thing.  You can do it.What is hilarious to me is the smokers who cry about welding galvanize.  That's funny.life is good
Reply:It doesn't seem like you can sand the zinc off like paint. It just seem like when I sand it, I don't seem to get to the steel. So can I just weld away or should I sand regardless?
Reply:Zinc will also produce some interesting spiderweb-like crap all over the weld area that can catch fire and burn on its own.  Keep some sand or an extinguisher handy.  Make sure to keep it cleaned off as you progress.  I have found that with lower power feeders this stuff (the spiderweb stuff) can affect the contact of the wire with the base metal, i.e., you will be welding just fine and then it's like hitting a real rusty patch in mild steel and, bang, no contact.  Clean a bit off and youre welding again.  Anyone else had this experience?Last edited by smithboy; 08-06-2005 at 01:11 PM.Smithboy...if it ain't broke, you ain't tryin'.
Reply:As you run your bead on the galvanized you might use a forward backward motion so that the wire burns ahead and elongates the puddle.  It will encourage the zinc to vapourize before the main part of the puddle reaches the area.
Reply:Followup:  just can't get any clean welds on this stuff.  To clean it, I grinded the pieces down with a bench grinder, but the welds come out bad.  The only acceptable ones are lap joints.  I've noticed that there cannot be any gap between the adjoining pieces, otherwise I get a hole.  I've tried playing around with the speed and power settings, but the B-2 setting is where I'm left at.  The zinc coated steel is supposed to be 14 ga. so I assume that the .035 wire is supposed to work.Even with the work clamp on the actual material iteself, I still have a little trouble with the initial arc.  How much current does this lincold sp-135 draw?  I've plugged into the same receptace shared with my dryer, and there's no problems with fuses blowing.Also, it seems like I have to speed up prevent from making a hole.  Should I turn down both the power and speed?
Reply:I just found out that Praxair sells a gas mixture they call, "Helistar GV" which is a blend designed for mig welding galvanized steel.  If you really want to weld some galvanized, you might give this a try.-Heath
Reply:lv guy,  I would try to use atleast a 20 amp breaker to run your machine if possible and make sure that nothing else is running on the circuit.  Here is a trick you can do with galvanized metal if you have a torch.  Heat up the weld area until the galvanizing starts to flake and burn off, clean it up with a wire brush, and then you can weld it no problem.  I have welded a good bit of Galvanized pipe on agricultural irrigations and that method always served me well.   Good luck  ~Jackson
Reply:iv   guy            I have had alot of succses with 0.35  NR 211 on 16 Ga galvanized   try turning down the volts a bit more than you would normally  use   on ungalvanised 16 Ga and run with 1\2-3\4  wire stick out  the galvinizing   makes the weld puddle run hotter. hope this helps