Welding Magnesium

CTRaceWorx

CTRaceWorx

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Has anyone done this. Before I jump into something that could be potentially dangerous I thought I'd ask about oddball things that I need to know. The fact that once it ignites you can't put it out except with a special foam makes me a little nervous to be honest, esp when water intensifies the fire. Any personal experience would be great. Oh, and the welds need to be done on a valve cover.
 
It welds alot like Aluminum, doesn't require quite as much heat tho. It has to be clean clean clean, if you've ever TIG'd aluminum and think that it was picky, clean it 3 times as much for magnesium

If its thicker than probably 1/4" you are going to need a 200+ amp TIG machine, adding helium to the gas mix helps alot with penetration.

Are you just repairing a crack or welding an extra piece do the valve cover?

Be super careful with the filings, and grinding dust, It will burn super hot, super fast and explode when you goto throw water on it to put it out.

I wouldn't recommend trying to MIG weld it, so i hope you have a tig machine. Set the machine up just like you would weld aluminum or similar thickness. Use az101 filler rod, and keep the arc length super small, like as close a physically possibly without out touching the puddle
 
I don't think I'd ever try to weld it. I don't get around much magnesium, but I'd expect it to be somewhat tedious and possibly dangerous. From what I understand, TIG is preferred and as stated above, it welds similar to Aluminum.
 
hotness said:
It welds alot like Aluminum, doesn't require quite as much heat tho. It has to be clean clean clean, if you've ever TIG'd aluminum and think that it was picky, clean it 3 times as much for magnesium
If its thicker than probably 1/4" you are going to need a 200+ amp TIG machine, adding helium to the gas mix helps alot with penetration.
Are you just repairing a crack or welding an extra piece do the valve cover?
Be super careful with the filings, and grinding dust, It will burn super hot, super fast and explode when you goto throw water on it to put it out.
I wouldn't recommend trying to MIG weld it, so i hope you have a tig machine. Set the machine up just like you would weld aluminum or similar thickness. Use az101 filler rod, and keep the arc length super small, like as close a physically possibly without out touching the puddle
Click to expand...


This is exactly what I needed to know. Yes it will be TIGed and yes I have welded plenty of aluminum so I know what to expect on that side of things. I will need to fill some holes in on the valve cover. I was concerned with the thought of the back side of the valve cover while filling in the holes would not have enough shielding gas and ignite from the back side. This probably isn't something that will happen but you obviously know what mag looks like when it ignites.....you cant look at it its so bright.
Thanks again for the info!
 
back gas it if you are concerned with it igniting from behind.

I've seen alot of magnesium fabrication done in purge chambers, maybe its for that reason

I have never tried to fill a hole with it, but you can definatly back the hole with some copper or aluminum
 
would also recommend haveing a suitible class D fire extinguisher at your side suitible to put out what your working on if something bad happened.

Ive seen several military H1's burn to the ground due to going too fast on the magnesium runflats makes a ugly bright unextinguishable fire if you dont have a class D extinguisher.
 
I had a set of old speed brakes off of an airplane. Through them in a brush fire for one of those "let's see what happens". It took awhile but once they lit it sounded like a rocket taking off, nice fire accelerator and blue/white flames!

But, it can be done. We had several mag aircraft steps repaired before when I was working on Citations.
 
The only other thing I can add that hasn't been touched on is to have a really good grounding bond. While repairing a magnesium part I had the ground blow a hole out of the part as it established contact.....shit more work after that.
 
The valve covers on a Chrysler 4.7L V-8 were magnesium for a few years now they are plastic, Volkswagon used it for engine blocks and such too.
 
hello

CarolinaTruggies said:
Has anyone done this. Before I jump into something that could be potentially dangerous I thought I'd ask about oddball things that I need to know. The fact that once it ignites you can't put it out except with a special foam makes me a little nervous to be honest, esp when water intensifies the fire. Any personal experience would be great. Oh, and the welds need to be done on a valve cover.
Click to expand...
buy a bigger shop and hire this guy full time and pay me really good!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!:driver:
 
CarolinaTruggies said:
I was concerned with the thought of the back side of the valve cover while filling in the holes would not have enough shielding gas and ignite from the back side.
Click to expand...

You could run a separate line of shielding gas to the other side. A V/C would lend itself to this since it can be laid flat to somewhat seal along the gasket surface. You'd want to keep the pressure low enough so it wouldn't affect the weld puddle.

Purple K fire extinguishing agent is what you want to have for this deal. Beware, it will work due to the fact that it stops all chemical reaction

The human body is a chemical reaction, so don't use it in a confined space without the proper respirator.
 
buckshot500 said:
You could run a separate line of shielding gas to the other side. A V/C would lend itself to this since it can be laid flat to somewhat seal along the gasket surface. You'd want to keep the pressure low enough so it wouldn't affect the weld puddle.
Purple K fire extinguishing agent is what you want to have for this deal. Beware, it will work due to the fact that it stops all chemical reaction
The human body is a chemical reaction, so don't use it in a confined space without the proper respirator.
Click to expand...
Purple K is a BC agent for use on flammable liquids & gases, and energized electrical equipment. You want a class D agent for magnesium fires. Class D agents will smother the fire and act as a heat sink.
 
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