It may be possible that the material is one of the 7XXX series, of which, many are not weldable.

If you are pretty sure that it is mag then, one quick way to distinguish between aluminum and magnesium is to file of some shavings and light them on fire. If it's mag then the filings will burn white, and fast. Another method I have heard of, though I have never personally tried it, is to put battery acid on the filings. Mag will turn black, aluminum will not change.


Magnesium will weld very similar to aluminum. Both materials have a passive oxide layer that should be removed prior to welding. If TIG welding use AC. If MIG welding use the usual DCEP polarity. Obviously use magnesium filler metals, and 100% argon gas. Something to keep in mind is that mag has a lower thermal conductivity than aluminum, but has a higher coeffecient of expansion than aluminum. This will make it more prone to distortion than what you would typically see with aluminum.

 

Thanks for the quick reply. And now that you mentioned it, I didn't have to push the pedal as far down as I would have with al. of the same thickness.

I will give the burning the filings a try.

BTW, any recommendations on an epoxy-like adhesive that I could use should it so happen that I will not be able to weld this?

 

I find that when tig welding magnesium, it gives of a greeish glow.
What you might have is "white" or "pot" metal, it is possible to weld this but it is difficult.

 

Note, if you do the burn test, do it in a SAFE place!

Magnesium burns hot-hot-hot. And water or other common fire-extinguishing agents will -not- put it out. (one common emergency fire starter for camping/emergency use is a block of magnesium, you shave off some metal and then hit it with a spark from the built-in 'flint', result is FIRE).

Magnesium is a -little- lighter than aluminum (0.0629 lb/in3 for pure mag versus 0.098 lb/in3 for pure al up to .102 lb/in3 for 7075), but their melting points are pretty close (1200F for pure mag, 1220F for pure aluminum).

The coefficient of thermal expansion of aluminum and magnesium are pretty darn close (15.2 micro-inch/inch-F for pure al versus 16.4 micro-inch/inch-F for pure mag, over a range up to 900F or so), but the magnesium takes about 20% more heat to raise its temp the same amount as the aluminum. The thermal conductivities differ by about 30% pure-vs-pure, and depending on what your mag alloy may be it could be a 50% difference.

Are you dealing with cast or extruded metal?

I'd probably compare weight, then do the shavings fire test. Light and burns, it's magnesium. Otherwise, it's probably an aluminum alloy.

To put it together, maybe bolt or rivet it.


And the 7xxx sereies aluminum alloys are generally unweldable.

 

Well it depends...

never done it myself but I´ve heard that is very dangerous to weld it...

Don´t know your capacity but even pro´s here said don´t do it.

What´s the piece?

 

Good topic, I've got a crankcase cover for a motorcycle that may or may not be magnesium and it needs some welding done to it. I didn't know where to start.

 

Well it depends...

never done it myself but I´ve heard that is very dangerous to weld it...

Don´t know your capacity but even pro´s here said don´t do it.

What´s the piece?

The workpiece is this:

I have a Honda S2000. One of the options sold in Europe and Asia is a flat-bottomed or "D" shaped steering wheel. Being such a small car, every extra inch of room here and there helps alot. It would cost several hundreds of dollars to obtain one. On top of that, the hub would need to be machined to fit the US model. So what I am doing is experimenting with a junk one to see if it will work.

The wheel is a three spoke design and what I did was cut the bottom spoke where it meets the rim. Then I cut the rim at the 6 o'clock position. I then hammered it flat from about 4:30 to 7:30. It's looking real good but all I have to do now is try and get it welded. When I tried it earlier today, it welded like al. but the molten puddle would collapse after a while. I guess it didn't help that I was using al. filler. On a sidenote, I have welded potmetal somewhat successfully in the past and it wasn't welding the same as that which further leads me to believe it is magnesium.

I posted a question in the S2000 forums and they said that it is in fact made of a magnesium alloy. So anybody know where I can get ahold of some magnesium filler rod? Perhaps someone would like to donate about three pieces of 3/32 filler rod to the cause.

Thanks alot for all of the replies. Once this thing is completed, I'll be sure to post some pics.

 

Save yourself time, money and possibly burning down the block - Momo sells a steering wheel similar to what your desire - $200.

http://www.modacar.com/products/Honda/S2000/MMTSW/Momo+Trek+Steering+Wheels.html

 

Along the same lines, if you decide to weld it, you can also apply a few drops of Duzall Flux to a clean piece of the job in question.
If it is indeed Magnesium, the flux will rapidly bubble and turn black. If it is Aluminium, the flux will just simply sit there and do nothing.

Further information on welding magnesium:

http://www.weldwell.co.nz/advice/white/magnesiun_advice.htm

(yes, the webmaster spelled it wrong but the link works)

 

Save yourself time, money and possibly burning down the block - Momo sells a steering wheel similar to what your desire - $200.

http://www.modacar.com/products/Honda/S2000/MMTSW/Momo+Trek+Steering+Wheels.html

Microzone is right. Go spend the money and get the new one. If you haven't had enough experience with welding magnesium then I don't think steering system of a car is the place to start learning. Bad things happen when things such as suspension and steering systems fail when flying down the road. You not only risk your life, but also those around you.

 

Along the same lines, if you decide to weld it, you can also apply a few drops of Duzall Flux to a clean piece of the job in question.
If it is indeed Magnesium, the flux will rapidly bubble and turn black. If it is Aluminium, the flux will just simply sit there and do nothing.

Further information on welding magnesium:

http://www.weldwell.co.nz/advice/white/magnesiun_advice.htm

(yes, the webmaster spelled it wrong but the link works)

Duzall Flux? Very interesting. Never heard of anyone using that, might have to give a try sometime. Good tip. Thanks

 

Save yourself time, money and possibly burning down the block - Momo sells a steering wheel similar to what your desire - $200.

http://www.modacar.com/products/Honda/S2000/MMTSW/Momo+Trek+Steering+Wheels.html

Thanks for the link but I would like to keep the airbag. And I like custom parts you can't just go to the store and pick it off the shelf.

Guess I'm just gonna see if I can get some mag. filler rod and just go at it. Besides, what's the worst that can happen? The steering wheel goes up in flames? I'll let y'all know how it turns out.

Thanks for all of the great advise and I WILL be careful when attempting this so I don't end up :blob2: or :angel: :laugh:

 

Remember one thing here..

Have a deep hold dug somewhere to bury it if it catches fire..

It will not go out with water..:nono:
Or a fire bottle..

Don't bother even trying..


...zap!

 

Everyone keeps mentioning that Magnesium can not be put out with water...

Good point! . .. ... However, what has not been mentioned is this.

When I was in school for Aviation we were showed a film on how to deal with aircraft fires. Part of the film showed a wheel fire caused by bad brakes (some aircraft wheels are made of magnesium).

They used water on the fire as a demonstration of what not to do and the fired increased in intensity about ten fold.

DON'T EVER PUT WATER ON A MAGNESIUM FIRE! Period

Washman

 

Everyone keeps mentioning that Magnesium can not be put out with water...

Good point! . .. ... However, what has not been mentioned is this.

When I was in school for Aviation we were showed a film on how to deal with aircraft fires. Part of the film showed a wheel fire caused by bad brakes (some aircraft wheels are made of magnesium).

They used water on the fire as a demonstration of what not to do and the fired increased in intensity about ten fold.

DON'T EVER PUT WATER ON A MAGNESIUM FIRE! Period

Washman

Everyone's advice will be heeded. Thanks again for all of your input.

 

I've done a fair bit of Magnesium welding and it is totally different to aluminium to weld. It gives off a very dirty greenish haze and the impression is that the weld will look like cr@p but often that's not the case and it looks fine.
You need less amps, more cleaning action on the AC balance and if you have an inverter machine run the Hertz frequency around 80Hz, also Zirconated electrodes.
The most critical part by far is cleaning off the oxide and this needs to done by a die grinder using a high speed steel or carbide cutter. You will notice it doesn't clog the cutter like Aluminium and the Mag finish under the oxide comes up much shinier than Aluminium as well.
Don't bother using a "gas lens" the arc is so dirty you stand a good chance to cover the gas lens with contaminants.
We use AZ92A filler, it seems to be a pretty good match for most of the Mag repairs we do, particularly Mag castings.
Regards Andrew.

 

They used water on the fire as a demonstration of what not to do and the fired increased in intensity about ten fold.

DON'T EVER PUT WATER ON A MAGNESIUM FIRE! Period

When I was teaching chemistry, did the same thing with magnesium ribbon. Get it started, then feed it into a beaker of 0.01M nitric acid. Funny, they don't have me teaching intro chem anymore.

 

How do you prevent it from catching fire in the first place if you are welding on it?

 

hey all,

i find it strange (actually, hard to believe) that honda would go to the trouble and expense of using mag for a steering wheel. an unweldable Al alloy makes more sense to me but anyways...

while the fire risk with mag is very real it's actually quite hard to ignite a large hunk of the stuff- it's simply too good a heat conductor. the real danger lies in swarf/shavings- cleaning up ALL swarf is very important!

as said water and a mag fire= a bigger fire or even an explosion!
in the absence of a class D fire extinguiser a bucket of sand on hand is a good idea

don't know if SIFBRONZE products are available outside the UK but might be worth a google. they deal mainly with brazing products but sell small packets of speciality/expensive fillers- 6 rod packs of silver solder AND magnesium filler for example. very useful for one off jobs

 

How do you prevent it from catching fire in the first place if you are welding on it?

Also factor in the atmosphere. The heat and arc are there, but its surrounded by inert gas.

 

hey all,

i find it strange (actually, hard to believe) that honda would go to the trouble and expense of using mag for a steering wheel.

It's true. It is supposed to give a better steering feel. Nissan also used a mag. steering wheel core in their 350Z.

Also, thanks for the heads up on obtaining filler rod.

 

I've done a fair bit of Magnesium welding and it is totally different to aluminium to weld. It gives off a very dirty greenish haze and the impression is that the weld will look like cr@p but often that's not the case and it looks fine.
You need less amps, more cleaning action on the AC balance and if you have an inverter machine run the Hertz frequency around 80Hz, also Zirconated electrodes.
The most critical part by far is cleaning off the oxide and this needs to done by a die grinder using a high speed steel or carbide cutter. You will notice it doesn't clog the cutter like Aluminium and the Mag finish under the oxide comes up much shinier than Aluminium as well.
Don't bother using a "gas lens" the arc is so dirty you stand a good chance to cover the gas lens with contaminants.
We use AZ92A filler, it seems to be a pretty good match for most of the Mag repairs we do, particularly Mag castings.
Regards Andrew.

Thanks for the write-up. That was really what I was hoping for. BTW, the only tungstens we have are 2% thor. and ceriated. Think the ceriated will be ok?

 

I just wanna once again thank everyone for all of their great advice and words of precaution. There are so many knowledgeable welders on this site and I am very happy to have access to this wealth of knowledge. Hopefully I'll be able to get this project completed in the near future. And get it done safely as well.

 

Thanks for the write-up. That was really what I was hoping for. BTW, the only tungstens we have are 2% thor. and ceriated. Think the ceriated will be ok?

Yes rajun, go for the ceriated electrodes grind it to a point but only at a shallow angle as if you're running more cleaning action in the AC balance and lower hertz it is more likely to form a ball with a very sharp point. Not that this is a problem I just feel a shallow point gives me a bit more direction with the arc.
As Hotrodder said previously, clean up all your swarf and dust prior to welding, this is what will catch fire 1st. A friend of mine had been machining Mag on his lathe at home and didn't bother cleaning the swarf properly and he had a small blaze a few weeks later when some grinding sparks ignited it so be careful.
Regards Andrew.

 

Seems to me that a steering wheel made of mag would be something a mfg. would never do because of liability..ie fire in an accident. Not to mention how easily it breaks when stessed. Al-Mag would be more like it.
In the early 60's cars tried using mag on wheels(pontiac I believe) and they proved dangerous enuff in the case of fire but inside by your chest...wouldn't that be nice if you were pinned into a wrecked car??
I've welded it and the argon keeps it from burning.
Myself I would try tigging a small section with 5356 on just the edge and see how it fused...if it jumps right on it then it prolly ain't mag and you'll know after it cools because it sometimes cracks loose on it's own afterwards. BTDT
Some mag parts say so right on them BTW