http://en.wikipedia.org/wiki/Thermite
rust + powdered aluminium = Thermite
Needs a very high temperature to ignite it (welder?)
Time to sweep up
This was supposed to be tongue in cheek but then I found this
http://www.hanford.gov/rl/?page=542&parent=506
at the bottom of the page
[Edited on 18/10/06 by givemethebighammer]
I read about a bloke who used his bench grinder to dress up some aluminium bits where it was normally used for steel. Next time he gave some steel a
bit of stick a few days later, BANG! Took all the hairs off his forearms & his eyebrows & gave him flash burns over all his uncovered
skin
Apparently the mixture of steel & alloy grinding dust was near enough the same as used in WW2 incendery bombs.
mmmmmmmmm thermite. the favourite ingredient of brainiac to which all other burning things are measured.
i dont know about anyone else but when i here about these things i want to go and make some and test it
locost explosive anyone
We used a thermic lance to cut a skull out of an arc furnace which broke when I worked in a foundry, it was like a length of conduit with iron filings inside and pure oxygen blown through it. It needed an oxy-propane torch to light it and it went through everything it touched like a hot knife through butter.
Not made any thermite for years..... hmmm.... 
Oh, and the best way of getting it to light is by sprinking a layer of magnesium powder on top of the mix, then using magnesium ribbon as a fuse.
Chris
And don't do it in the kitchen!
quote:
Originally posted by Peteff
We used a thermic lance to cut a skull out of an arc furnace
They used a mixture of iron oxide and aluminium powder to coat the outer skin of the hindeburg to stop it absorbing too much sunlight. A spark on landing at new york ignited it. IT wasn't the hydrogen that burned (at first)
quote:
Originally posted by paulbeyer
quote:
Originally posted by Peteff
We used a thermic lance to cut a skull out of an arc furnace
That sounds a bit Fred West. What was a skull doing in a furnace and why did it need to be cut out?
Sounds to me as if kit car building and pyromania(?) go together.
Anyway you're all making life difficult ..... weedkiller and sugar are much cheaper/easier!!!
Cheers, Pewe
PS Just hope Special Branch don't monitor this site or they'll be trying to round us up as terrorist suspects - Chris W first as the
ring-leader
thermite isn't an explosive, it's just a powder that burns really really hot and isn't easy to put out, which is why it's used for
incendiary 'bombs'.
It's used for joining (in a kind of crude welding) railway tracks in a Siberian winter IIR my chemistry lessons
We set off a small amount in a crucible using magnesium ribbon, leaves a little blob of molten iron, but I think it's a teacher demonstration
these days (I'll ask the missus)
[Edited on 19/10/06 by iank]
It's a local foundry term Paul, sorry. It's a shell of metal that has set in the furnace which usually gets poured out with the melt.
A blob of thermite around the size of a 50p piece left on the bonnet of a car will go straight through including the block so i was once told. Ever tried powdering the stuff on sparklers and lighting that he he. Or the weedkiller and sugar classic. All in the name of science obviously. Household stuff is dangerous...
quote:
Originally posted by smart51
They used a mixture of iron oxide and aluminium powder to coat the outer skin of the hindeburg to stop it absorbing too much sunlight. A spark on landing at new york ignited it. IT wasn't the hydrogen that burned (at first)
Ah reminds me of the Jolly Rogers Cookbook that used to circulate school. Still around if you look hard enough
quote:
Originally posted by mistergrumpy
Ah reminds me of the Jolly Rogers Cookbook that used to circulate school. Still around if you look hard enough
surely that includes my passport?
Anyway, how does rust and ally go bang since both are already oxidised? Or do you have to catch the ally before it oxidises itself?
Ive seen aluminium swarfe burn in a factory - only a small amount but it was quite volatile. It was being cut by std cut off saw - heat of the swarfe ignited itself. Nasty stuff so be careful.
to answer my own question, its because a surface layer of ally oxide still leaves the vast majority as plain ally. I guess the heat of a bit burning
evapourates the surface ally oxide and starts a chain reaction.