Tig welding magnesium

Hello,
I have a Yamaha side cover that has a hole ground through it. It is
magnesium and I have not done any magnesium before. What is the best
way to go about tig welding it...required filler alloy? AC with
zirconiated? I have read that if the magnesium were to begin to
combust you can just watch it go for there is no chance of putting it
out. What a comforting thought. Anybody with some experience on this
want to give me a few pointers? Thanks for your time.
Randy
Reply to
r9565
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Welded several mag bike side casings, and really just as easy as normal cast ally.
Only thing is its very difficult to weld repair casings that are badly corroded, so best to use epoxy for these.
Reply to
Matt
No firsthand experience, but I was taught in various Navy & CG firefighting schools that magnesium fires can't be extinguished with conventional methods. As an aside we were also told if the fire was a public spectacle to just stand and train hoses on it to look like we were doing "something" while we watched it burn out.
If you do try it, I recommend you have the work piece situated where it can burn out without taking a building or nearby equipment with it. If it ignites it likely will be too hot and bright to remove to safer surroundings.
Reply to
Mark J
Firstly whay on earth should the workpiece ignite when its being welded? Secondly if you have no first hand knowledge, why make postings suggesting that you have?
Mattic
Reply to
Mattic
Well, let's see -- first he said "No first hand experience" - so much for "suggesting that you have". Second, while he may not have had first hand experience his information was valid. Have you ever seen a magnesium fire ?? Them suckers are HOT -- a chunk of burning magnesium needs to be viewed through welding glasses it is so bright, can melt it's way down through a steel plate with no trouble at all and is a real pain to put out. But wait you say, how can it get lit with the shielding gas around it ?? You move the shield away too soon while welding etc. I have seen a magnesium fire -- where I was working somebody got a small piece (couple of inches square) into the power sander and got it lit -- the other end of the large building thought the sun had come up until they saw the smoke rising. I don't know what the current process is for machining magnesium, but we used to ALWAYS have a bucket of talc next to the machines so we could throw it on the part to smother it if it got lit -- and that was only with machining which is not nearly as hot as welding. Magnesium is nasty stuff - wrap a piece around a steel bar and light it off -- cuts right through the bar. You want to experiment in your garage, go right ahead -- just make sure the neighbors have their fire insurance paid up on their houses.
Reply to
Mike Fields
I wonder have you actually ever welded magnesium?
Not done a great deal, but what I have done, was no problem at all, and nothing caught fire.
Also have a friend who used to fabricate mag parts for race cars............again no problems!
Mattic
Reply to
Mattic
Snipping good stuff by Mark...
Snip good warnings.... by Mike Fields
Perhaps rather than pissing and moaning about other people's advice, you might give some advice of your own!
So far two posts by a guy who claims to have done it have said nothing to answer the poor guy's questions.
It sure sounds to me like you want to work in a purged glove box, and be prepared for a fire you can't put out with water or CO2. Because once the fire starts, it's a little late to run out for a bucket of talc.
But the guy was asking about Fillers and amperages and electrodes so instead of saying "was no problem at all" you might just give an answer.
Reply to
Stuart Wheaton
Last time I had one done was on a little TY80 - WOW, way long time ago. I'm pretty sure it was heli-arc'd, though at the time I think the generic term was heli-arc anyway and just about nobody was using argon. As I understand it magnesium(pure) will take off when HOT in an atmosphere that is RICH in oxygen, not argon smothered.
Didn't we do that in lo skool chem ?, put the little ribbon of Mg in a flask, pump in O2, watch it burn. There musta bin a point to that demo...
Reply to
2regburgess
Likewise..................if you know nothing whatsoever about welding mag, then why post silly scare stories, which seem to suggest the op would do well to look for a new part, rather than repair what he has?
Mattic
Reply to
Mattic
You need mag filler wire: I use ceriated 1.6mm tungsten, with amps set in relation to thickness of material.
Mattic
Reply to
Mattic
I did my last piece of mag several years ago. weld it something like this. AC, pure tungsten, amps similar to alum. The differance is you put the ball of the tungsten in the molten puddle, not alot, just alittle. The mag will not contaminate the electrode. It's kind of neat really, the arc will hold the puddle away from it. use pre flow and lots of post flow on your sheilding gas.
Only a clas "D" fire extinguisher will work on magnesium. Water will make it burn hotter.
remove 333 to email reply. Thanks, Randy
Reply to
Randy
That's really stupid advice.
What you'd actually be doing is finding out the hard way just how innocuous a dry magnesium fire is, and how much of an inferno it turns into if you put water on it.
Reply to
Andy Dingley
I've never seen any on a road vehicle, even a motorbike. Magnesium on its own is a dreadful material - light, but with evil habits for corrosion and cracking. So if it's on a car, chances are it's actually an Elektron alloy - aluminium and magnesium. Even this is still a problem for corrosion - the old "wobbly web" wheels used on 1960's Lotus cars are no longer permissable for classic racing, they're just not trustworthy.
Which leads to my question - what do you use as a filler rod, and how sensitive is the choice of filler to the exact alloy you're working on?
I _have_ welded pure magnesium on a pushbike frame - a Kirk (Google, these things were infamous). But then I was doing this with an instructor over my shoulder and to be honest, he did much of it (I've negligible TIG experience)
Reply to
Andy Dingley
Some years ago, out in the San Diego area, I had a friend who worked for Halibrand.. He brought a big box of mag curls home one night and we blazed 'em in the back yard, pretty impressive. Extra-impressive when I poured beer on it:-D
John
Reply to
JohnM
Mg is a lot of fun. My father in law used a piece of Mg tubing for a lightnig rod over his TV antenna. He didnt know it was Mg. Lit the backyard up like daylite one night during a thunder storm.
Reply to
Jimmie

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