On Apr 17 2005, 7:32, Vintage Computer Festival wrote: sense of Probably not, actually. It's hard to get the stuff to burn, and it might well collapse under its own weight before you got it all that hot, at which point you'd probably remove the hot flame and emit a few hot words instead ;-) [1] Yes, the ignition temperature of some magnesium alloys is below the melting point, but you need an *awful* lot of heat to make it catch, not just a high local temperature. You also need an awful lot of heat to sustain it -- remember it dissipates heat readily -- and you need oxygen[2] to keep it going. Under normal welding conditions, the inert gas used for TIG/MIG excludes the oxygen (that's the whole point of the method) and the heat is highly localised, and other techniquesuse much lower temperatures. TIG welding of mag alloys is quite commonplace, and most items of magnesium alloy you'll come across are heat treated during manufacture, at high temperatures. This is not something you can do at home with a paraffin (kerosene) blowlamp, it's usually done in ovens in an inert atmosphere, but it's nevertheless standard procedure. If you want to know just how hard it is to burn a mag alloy chassis, take a look at Simson Garfinkel's infamous webpage at http://simson.net/photos/hacks/cubefire.html and note how much gas it took to cause even sporadic ignition. It was a pile of molten slag by the time it caught. Disclaimer: if you do have an enormous blowtorch, don't blame me if you set your workshop on fire. However, if you have such a blowtorch, you can do that more easily without the magnesium alloy :-) And if you do set a magnesium alloy chassis alight, there's not much will put it out. For small fires, copious water (not a spray) to deluge it is sometimes used, but common practice, I'm told, is to protect the surroundings and let the metal burn out. There's at least one firefighter on the list who might know more about that than I do. [1] Yes, I found out the hard way when trying to repair something. [2] Or more usually air. However, once the reaction gets going, magnesium is sufficiently reactive to burn in carbon dioxide or nitrogen, stripping the oxygen from CO2 leaving soot behind, or forming magnesium nitride. Standard school chemistry demonstration. That's why MIG/TIG for aluminium and magnesium (and their alloys) use pure argon instead of cheaper gasses. -- Pete Peter Turnbull Network Manager University of York