Aluminum or Magnesium Scrap

[motordude]

Hello Roger,
thanks for your reply. Again, adding Mg does not remove any carbon from the melt, it only changes the shape and distribution of the graphite. To remove carbon, one needs to add oxygen (O2). The O2 dissolves the carbon and leaves the melt as CO or CO2. The Mg causes the graphite to grow as spheres, where as in "normal" castiron the graphite grows as flakes. It does not remove any carbon in the process. The Mg is vaporised and the vapor travels throught the melt and lowers the sulphur content and promotes formation of spherodial graphite.

regards

John

[Kevin Taylor]

Most domistic trans cases are Aluminum but REKD is right VW heads are ok mag usualy turns almost black from weather I heard of a guy sanding on a VW case to pretty it up and his shurt was filled with the dust and he made a spark when he hit a stud in the case and he lit up like a road flare to make mater's worse the polister shirt shrinkwrped him the chips from milling do make an exelinte distress flare. There are a lot of nice castings in the scrap thies days. alot of aircrart castings are also Mag

[CypherNinja]

Ok, sorry guys, but I had to register to say this.

I was laughing at this thread when I saw this......

Originally Posted by DragnsBane I seem to recall reading somewhere that if you put a few small drops of distilled white vinegar on magnesium it will bubble furiously while aluminum will do nothing. I'll have to check to be sure.

All other amusing methods aside, that is indeed the easiest way to test. Its pretty much standard practice in welding; an "old welder's trick" of sorts.

Just put a drop on the metal; if it foams it's magnesium, if nothing its aluminum.


Cheers, I'm off to read more about ball screws.......

[tool_man]

When I was in the Army,I saw a guy set a Thermite grenade on top of a V-8 engine block and pull the pin.About 15 seconds later,it dropped on the ground.I was impressed.At one time,thermite was commonly used to weld thick iron sections.I really don't think it would be an economical method of melting iron for casting.Not sure what is in that massive white cloud of smoke either but,I am sure it is not healthy to breathe it.

[vwdevotee]

Originally Posted by Rekd BTW, if the tranny tails are off a VW, it's magnese.. 'Rekd

Not always. Original (very old) transmissions and engine blocks from VW were an aluminum/magnesium alloy. Later air cooled models (around 1970 comes to mind) they started hasing out the magnesium. One needs to be really careful though because automakers are starting to reintroduce magnesium to reduce weight and vibration/noise in certain parts.

[widgitmaster]

This was one of the few posts which held my attention straight to the end!
Well done!

Eric

[wildcat]

Given all the interesting talk on burning metal powder some may be interested in http://en.wikipedia.org/wiki/Thermite especially some of the links to videos/pictures towards the bottom.

[U238]

Originally Posted by foamcutter Okay Guys, Is there a good way to tell the difference in Aluminum or Magnesium scrap? I think I have aluminum but I'm not totally sure. I bought some transmission tails and valve covers the scrap place said were aluminum. I just would like to know if there is an easy way for me to tell the difference. Thanks for the help Ron

Yes there is a very good and safe way to tell the difference between Aluminum and Magnesium. Place a small drop of Duzall Flux on the piece in question. If the remains clear it is Aluminum. If the drop turns jet black it is magnesium. Duzall is liquid flux used for soft soldering. It can be obtained from most welding supply houses. Duzall is a trade name of the Esab Co.
This stuff is not expensive comes in a small plastic bottle and is acid based, so be carefull with it. Handle it with the respect that any acid needs.