alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
perhaps i'm mistaking magnesium as something else... say, cast
aluminum.

i occasionally get work to weld unknown aluminum castings..
when they dont weld, i attribute it to being and 'unweldable
aluminum alloy' ... (i get good results welding aluminum otherwise)

but maybe its magnesium? and i should start learning how
to weld it.

so the question is: what's magnesium usually used for?
i must be used abundantly enough to warrant sections in welding
texts.. usually bigger chapters than welding titanium, for example.

and how do i identify it?

aside from the fact that WELDING magnesium sounds
downright dangerous after all the commotion in my highschool
chemistry class, watching it explode into flames.

thanks,
-tony

tony wrote:
alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
snip
and how do i identify it?

Cleaning a bare spot, then dripping vinegar on it will cause most
magnesium alloys to generate some bubbles.

A lot of earlier VW beetle crankcases are magnsium.

tony wrote:

alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
perhaps i'm mistaking magnesium as something else... say, cast
aluminum.

i occasionally get work to weld unknown aluminum castings..
when they dont weld, i attribute it to being and 'unweldable
aluminum alloy' ... (i get good results welding aluminum otherwise)

but maybe its magnesium? and i should start learning how
to weld it.

so the question is: what's magnesium usually used for?
i must be used abundantly enough to warrant sections in welding
texts.. usually bigger chapters than welding titanium, for example.

and how do i identify it?

aside from the fact that WELDING magnesium sounds
downright dangerous after all the commotion in my highschool
chemistry class, watching it explode into flames.

thanks,
-tony

On Mon, 03 Nov 2003 21:41:35 GMT, "tony"
wrote:

wondering what kind of parts
are typically made of magnesium.

Not many. Magnesium is a lousy metal in service, because it corrodes
like crazy and also has cracking problems. If you meet a "magnesium"
casting, then the chances are that it's actually Elektron - an alloy
of aluminium and magnesium. Aluminium's self-passivating oxide film
protects against the worst of the corrosion.

If you find old copies of Flight magazine from the late WW2 period
you'll see _lots_ of adverts for magnesium "The wonder metal that will
rebuild our country when peace comes". Although it was developed
enormously for wartime aircraft, its poor long-term service made it
fall from favour by the early '50s.

In the '60s, Lotus racing cars were designed by Chapman on his
"simplificate and add lightness principle". The "wobbly web" wheels of
the type 23
http://www.motorcities.com/contents/00JTH504579522.html
are so infamously unsafe today that they're no longer allowed on a
track, and are replaced for competition
http://www.srgtc.org.uk/images/Lotus_23B.jpg

The "Kirk" bicycle of the late '80's was a cast magnesium frame. Not a
bad road frame (until it cracked or turned to dust) but absolute
rubbish as a mountain bike. There are many stories of them returning
from rides in two halves.

Magnesium is a useful stiffening addition to aluminium alloys.
Although the density of the casting isn't much less than another
aluminium alloy, the extra stiffness may allow thinner walls. These
are obviously lighter, but thin castings are also easier castings to
make. This is why Volkswagen used it (intermittently and not
universally).

Pure magnesium is mainly used as diecastings, because it has suitable
properties for easy casting. AZ91 is the usual alloy (9% Al), either
AZ91B or AZ91HP - trace elements (mainly iron) are reduced for the
High Purity form, which improves corrosion resistance.

These days it's cropping up increasingly often, but it's mainly for
its easy casting and light weight in relatively low-stressed consumer
goods. The NeXT computer (the cube) had one of the first magnesium
cases and they're now commonplace for cellphones.

--
Die Gotterspammerung - Junkmail of the Gods

On Mon, 03 Nov 2003 22:37:03 +0000, David Billington
wrote:

A lot of earlier VW beetle crankcases are magnsium.


A PhD chemist I work with used to work as a firefighter, both
volunteer and paid, for quite a while. He said you have about ten
minutes to put out a VW beetle fire before the magnesium catches.
Once that happens, it takes about 5,000 gpm of water to put it out.
Less water just makes it worse, due to the very exothermic
dissociation and reforming of the water molecules caused by the
intense heat.

He says they took a lot of crap from other fire companies once for
having a "three alarm car fire", but they got it out (it was in a
garage). Usually, once the mag case caught, they just let them burn.

Pete Keillor

tony wrote:

alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
perhaps i'm mistaking magnesium as something else... say, cast
aluminum.

i occasionally get work to weld unknown aluminum castings..
when they dont weld, i attribute it to being and 'unweldable
aluminum alloy' ... (i get good results welding aluminum otherwise)

but maybe its magnesium? and i should start learning how
to weld it.

so the question is: what's magnesium usually used for?
i must be used abundantly enough to warrant sections in welding
texts.. usually bigger chapters than welding titanium, for example.

and how do i identify it?

aside from the fact that WELDING magnesium sounds
downright dangerous after all the commotion in my highschool
chemistry class, watching it explode into flames.

thanks,
-tony

Ian Stirling wrote:

tony wrote:
alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
snip
and how do i identify it?

Cleaning a bare spot, then dripping vinegar on it will cause most
magnesium alloys to generate some bubbles.

One real good telltale that you may be deling with Magnesium is when
the part seems to be too light weight for it's size.

Vinegar on a fresh scraped spot of bare metal will react with bubbles
and a purpleish darkening.

Scrapings or filings will light on fire if they are fairly fine. This
is the principle behind some emergency firestarters.

You will get your excersise trying to break a magnesium casting like a
trasmission case or oil pan. The one Mag. oil pan I did break up nearly
got me. With it on a concrete floor, a 12 LB hammer rebounded almost all
the way back when I struck it. I nearly took the hammer on the forehead.
Wicked rebound. I should have clued in then, but I got it broken up.
Once I tested it, I junked most of it, as it was of no use for my
casting use.

Cheers
Trevor Jones

I do a lot of alum welding myself and checked into welding Magnesium but the
process was more than I wanted to invest. What I was told is you need a
sealed vacuum chamber to weld in so that the air bubbles can escape the
metal. Anyhow I have several old engine cases made of Mag, The old VW
air-cooled engines were magnesium, Porsche used a lot of it in there engines
and transmissions, I had some aircraft engine case parts welded that were
also magnesium, its very light weight, strong if its the right alloy and if
its an old part it will be a darker grey in color not shinny like aluminum.
The weight is the big difference, you can really tell when you compare it to
aluminum.

Craig

"tony" wrote in message
...
alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
perhaps i'm mistaking magnesium as something else... say, cast
aluminum.

i occasionally get work to weld unknown aluminum castings..
when they dont weld, i attribute it to being and 'unweldable
aluminum alloy' ... (i get good results welding aluminum otherwise)

but maybe its magnesium? and i should start learning how
to weld it.

so the question is: what's magnesium usually used for?
i must be used abundantly enough to warrant sections in welding
texts.. usually bigger chapters than welding titanium, for example.

and how do i identify it?

aside from the fact that WELDING magnesium sounds
downright dangerous after all the commotion in my highschool
chemistry class, watching it explode into flames.

thanks,
-tony

I watched a guy weld a magnesium gearbox a few years ago. I thought
for sure it would catch on fire, but he tig welded with no problem -
as if it were aluminum.


"Craig Garrett" wrote in message ...
I do a lot of alum welding myself and checked into welding Magnesium but the
process was more than I wanted to invest. What I was told is you need a
sealed vacuum chamber to weld in so that the air bubbles can escape the
metal. Anyhow I have several old engine cases made of Mag, The old VW
air-cooled engines were magnesium, Porsche used a lot of it in there engines
and transmissions, I had some aircraft engine case parts welded that were
also magnesium, its very light weight, strong if its the right alloy and if
its an old part it will be a darker grey in color not shinny like aluminum.
The weight is the big difference, you can really tell when you compare it to
aluminum.

Craig

"tony" wrote in message
...
alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
perhaps i'm mistaking magnesium as something else... say, cast
aluminum.

i occasionally get work to weld unknown aluminum castings..
when they dont weld, i attribute it to being and 'unweldable
aluminum alloy' ... (i get good results welding aluminum otherwise)

but maybe its magnesium? and i should start learning how
to weld it.

so the question is: what's magnesium usually used for?
i must be used abundantly enough to warrant sections in welding
texts.. usually bigger chapters than welding titanium, for example.

and how do i identify it?

aside from the fact that WELDING magnesium sounds
downright dangerous after all the commotion in my highschool
chemistry class, watching it explode into flames.

thanks,
-tony

May be OK as long as you have the shielding gas present for sufficient
time to allow cooling below a critical temperature. Also it is dependant
on surface area in that it is less likely to burn as a molten pool than
as some form where the surface area is greater such as a powder. I have
seen magnesium swarf thrown into a bonfire and it didn't burn probably
due to to much surface oxidation. This was the expected result as the
next thing you did was throw water on it. That made it burn with a very
big white flash.

John Baron wrote:

I watched a guy weld a magnesium gearbox a few years ago. I thought
for sure it would catch on fire, but he tig welded with no problem -
as if it were aluminum.


"Craig Garrett" wrote in message ...

I do a lot of alum welding myself and checked into welding Magnesium but the
process was more than I wanted to invest. What I was told is you need a
sealed vacuum chamber to weld in so that the air bubbles can escape the
metal. Anyhow I have several old engine cases made of Mag, The old VW
air-cooled engines were magnesium, Porsche used a lot of it in there engines
and transmissions, I had some aircraft engine case parts welded that were
also magnesium, its very light weight, strong if its the right alloy and if
its an old part it will be a darker grey in color not shinny like aluminum.
The weight is the big difference, you can really tell when you compare it to
aluminum.

Craig

"tony" wrote in message
...

alot of the newer welding books have steps/tips on welding
magnesium.. i'm not so much particularly interested in learning
to weld magnesium as much as wondering what kind of parts
are typically made of magnesium. steel i can recognize.. but
perhaps i'm mistaking magnesium as something else... say, cast
aluminum.

i occasionally get work to weld unknown aluminum castings..
when they dont weld, i attribute it to being and 'unweldable
aluminum alloy' ... (i get good results welding aluminum otherwise)

but maybe its magnesium? and i should start learning how
to weld it.

so the question is: what's magnesium usually used for?
i must be used abundantly enough to warrant sections in welding
texts.. usually bigger chapters than welding titanium, for example.

and how do i identify it?

aside from the fact that WELDING magnesium sounds
downright dangerous after all the commotion in my highschool
chemistry class, watching it explode into flames.

thanks,
-tony

David Billington wrote:

..A lot of earlier VW beetle crankcases are magnsium.

So for a time were the gearboxes of Bristol engined buses!
After a fire when one was on a milling machine in the factory, extra
flood coolant was installed,
and special fire-fighting equipment around the machine shop.

From then on, all Bristol-engined buses and lorries with the magnesium
boxes were identified externally by different
- hexagonal - wheel hub centres - just so that fire crews etc could
idenify them in an accident.

Dave.

Bristol, UK

At Roush Racing we used to make bell housing and brackets out of Mag, neat
stuff.



Russ Wizinsky

www.professorwiz.com
www.metalhobbies.com