Rims

[TheMinister]

I believe Magnesiun burns very well(white hot) when lit on fire.

If you can only believe that, you must have missed out on good chemistry lessons at school. I used to love getting the magnesium strips and setting fire to them when the teacher wasn't looking. Kind of impossible to hide once it's lit, but very good fun. Also magnesium filings burn fantastically.

If you want to try yourself, those metal pencil sharpeners you can get are often magnesium.

[manchild]

If you want to try yourself, those metal pencil sharpeners you can get are often magnesium.

Are you aware how many teenagers might read your post and try it without being warned?! [-X


So, let me write something opposite ASAP:


DON'T TRY IT!

IF YOU DID, THAN DON'T TRY TO EXTINGUISH BURNING MAGNESIUM WITH WATER!

[youtube]http://www.youtube.com/watch?v=rogZBXNqaMo[/youtube]

Magnesium in compact form is uncritical, as long as it is not carried to a temperature lying above its melting point. Due to the good caloric conductibility of magnesium it is not easy to ignite magnesium components. This is different for magnesium dusts and magnesium chips, they are easily flammable. Furthermore, magnesium dusts, when whirled up in air, are explosive. Also, as to magnesium dusts, there is a self-ignition hazard. Molten magnesium ignites when exposed to air and burns at the surface if no appropriate protective measures have been taken.

Magnesium has the capacity to react chemically not only with air but also with a great variety of other substances, preferably with oxygenous compounds. Magnesium reacts e.g. also at low temperatures with water, with hydrogen being released. Wet magnesium chips and dusts may release so much hydrogen that the latter one forms an explosive mixture with the air (oxyhydrogen gas).

One can expect dangerous reactions particularly at higher temperatures, i.e. in case of molten and burning magnesium. Due to the high calorific intensity of magnesium (up to 3000°C), it is impossible to extinguish a magnesium fire by using water or hydrous extinguishing substances. The water dissociates, i.e. it splits up into its constituents hydrogen and oxygen; oxyhydrogen gas reactions with potentially fatal effects are the consequence.

It is extremely difficult to extinguish magnesium fires. Extinction is effected by smothering the fire using extinguishing substances which are appropriate for metal fires.

Examples for appropriate extinguishing substances:

- extinguishing powder of fire classification D
- dry covering salts for molten magnesium
- dry sand
- dry rust-free gray-cast iron chips
- extinguishing gases (e.g. argon) under special circumstances

Examples for inappropriate extinguishing substances:

- water!
- extinguishing foam!
- extinguishing powder for fire classifications A, B, C
- extinguishing powder for fire classifications B, C
- carbon dioxide (CO 2)
- nitrogen (N 2)

http://wassie.gmxhome.de/magnesium/mg11/mg1e.htm

[Giblet]

Thanks Manchild.

Let's hope kids are more responsible now than I was then.

They aren't but it's nice to dream.

[manchild]

I know, I would have tried it too when I was a teen if I had access to any. No one told us that is is impossible to extinguish, and fortunately that sharpeners are made out of it. I've seen it in chemistry class, and it was enough, especially since it produces poison gasses.

[Pedro]

Wasn't this thread supposed to be about wheel rims? [-X

Look, so many chemists among F1 fans!