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