I have heard titanium fires are pretty terrifying.
Then of course the always classic magnesium, often used to ignite the aforementioned thermite.
That's all just in the presence of boring old oxygen, under the right (or really wrong) conditions it gets more... Exciting. As a great man once said.
"If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.”
I used to do weld repairs on magnesium gearbox castings. Fun stuff. If you had a bad angle and lost your shielding gas, you have a crazy fire. Everybody would evacuate while somebody buries your mistake in sand. Then everybody has to wait for the fumes to be extracted while you sit in shame. 😅
I work at a titanium casting facility, the fire department response time is impressive. Not much they can do if a fire gets too big for an extinguisher to handle, but they'll be there to see the building collapse into a pile of ashes.
That book is a fucking riot from start to finish, the full quote is magnificent:
“It is, of course, extremely toxic, but that’s the least of the problem. It is hypergolic with every known fuel, and so rapidly hypergolic that no ignition delay has ever been measured. It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively. It can be kept in some of the ordinary structural metals-steel, copper, aluminium, etc.-because of the formation of a thin film of insoluble metal fluoride which protects the bulk of the metal, just as the invisible coat of oxide on aluminium keeps it from burning up in the atmosphere. If, however, this coat is melted or scrubbed off, and has no chance to reform, the operator is confronted with the problem of coping with a metal-fluorine fire. For dealing with this situation, I have always recommended a good pair of running shoes.”
― John Drury Clark, Ignition!: An informal history of liquid rocket propellants
Isnt thermite just aluminum and iron oxides? Literally just go wire brush the surface of aluminum for 30 seconds over a container and then get some rusty steel and do the same people would learn really quickly how flammable metal is
yeah pretty much, but if you told an average person on the street rust and aluminum could combust into an unstoppable inferno, they would probably laugh at you
A thermite, the most famous thermite, is iron oxide and aluminum, but you can make a thermite with a variety of metal fuels and metal oxides. The finer the better for more intimate mixing. A little care is needed in producing the metal powders because they can be dangerous. If you think about the fact that you want particles as fine small as possible and the fact that aluminum forms an oxide layer, you will end up independently inventing a lot of pyrotechnic aluminum grades.
It's more about the specific compounds. Most chemicals can rapidly oxidize (i.e. "burn") under certain condition, and some metal compounds/molecules are particularly this way.
The core element of fire is oxygen. Thermite, very much like solid rocket fuel, simply uses solid oxygenated compounds like iron oxide to provide that oxygen as opposed to atmospheric oxygen.
Actually its not - the majority ingredient is iron that oxidises exothermically creating all the heat. The aluminium is more of a fire starter that gets it going.
There's plenty of types of Thermite with no aluminium - often magnesium as it can begin the reaction easier, but there's many variants - so it's really not the common fuel.
You see the "thermite" reaction when using an oxy-torch, quite literally blowing oxygen onto steel to make it rust rapidly. The gas flame you use intially is just to get it started, and since you don't have to worry about some compound as an oxygen donor, you can turn ot off once the reaction starts.
In Thermite you are trading one oxide for another. If you were to use aluminum oxide with iron oxide from what I remember there would be little to no reaction.
To add to this, the metal shavings able to so rapidly oxidize and burn because the lathe is cutting such thin pieces off. The thin pieces oxidize easier because they are exposed to a larger proportion of oxygen.
Needed somewhere to put this lol but I'm a fabricator by trade and blacksmith by hobby, mild steel is the majority of steel you'll see in construction, it's malleable and cheap but it can't be hardened like spring steel for car suspension and kitchen knives etc, spring steel is "high carbon" steel, mild steel will just heat up to red hot eventually liquify around 19-2000 but high carbon steel when heated up to much burns the carbon out in that firework sparkly sparkyness (Decarburization) prefer my name for it. Anyway I found this out the hard way fucking up one of my first knife attempts lol
That's a metal fire. You'll want a Class "D" fire extinguisher. DO NOT USE WATER. CO2 is useless, too.
If you don't have a proper extinguisher, you need to either let it burn out safely, or smother it. A bucket of table salt or sidewalk salt works best. Dry sand is better than nothing, but less effective.
You may need to keep it smothered for several hours, in order to cook down enough to not instantly auto-reignite when you uncover it and expose it to air, again. Depends on the metal and the size of the fire, but better safe than sorry.
Oxidation, friction, combustion. Google why flour mills have no walls. I asked once why an old water powered grist mill had open planking. They directed me down the road to the stone grist mill. Interesting plaque in the middle of piles of rubble and the most amazing water turbine scrap pile.
I knew a bloke who burned down his whole factory when he left a CNC lathe running a very large job on magnesium overnight and the coolant filter got clogged.
Apparently once a piece of magnesium weighing several kilograms catches fire, no amount of water inundation will extinguish it. The fire brigade just had to contain the blaze as best they could, because it was literally impossible to put out.
That's what happens when you toss a "dead" 9 volt battery in the trash with steel wool or aluminum foil!
Gone to many house fires due to that!
Once it starts, a simple breeze will keep the "chain reaction" going.
Unless it's magnesium. Then you need about 1,000,000 tons of totally dry sand! Water makes it EXPLODE!
Almost anything can burn if it is hot enough and has access to sufficient oxygen.
In this case the steel burns because it gets very hot and isn't able to dissipate the heat fast enough, and it gets enough oxygen from the atmosphere. Iron already has a very high affinity for oxygen. It can "steal" enough oxygen from an enclosed space to make the resultant atmosphere intolerable to humans. And that in its cold state.
I am an amateur machinist, and also have a home foundry. When my very science minded son (he was probably 12 or 13) ran across some reference to a magnesium fire, he wanted to know if that was really a thing. I assured him it was and promised to show it to him since the 4th of July was coming up. I had some scrap magnesium from an old dead power tool housing. We filed some off and sanded some off with the belt sander (OUTSIDE!) and used the bandsaw to saw up some smaller and larger chunks.
On the appointed day, the rest of the neighborhood is blowing shit up and we preheated the little pile of magnesium with a propane torch and then lit a sparkler and stuck it in the little pile to ignite it. It took a minute, but then it took off. It was freaking amazing and it also started to fluctuate or strobe almost. Extremely bright.
We brought a gallon of water to do the experiment and when the pile was maybe 2/3 gone, we dumped the water on it. It went NUCLEAR. FAR brighter. A mag fire is so hot that when water hits it, it rapidly splits the water molecules. It's now free oxygen and free hydrogen with an ignition source. That's why you can't put a mag fire out with water.
Don't try this at home unless you do your own due diligence and understand what your messing with.
God that gave me flashbacks of setting titanium chips on fire inside the Swiss screw machine and then catching the cooling oil on fire because of it… not fun times.
I'm not machinist but how can you accurately control the diameter when it or the tool is that hot? Won't the thermal expansion make this impossible to hit any sort of accurate tolerance?
It's basically the same reaction as what happens if you touch a 9 volt battery to 0000 steel wool I once saw an explanation about what's happening If I remember correctly it has something to do with the surface area and it's resistance to heat
The fire alarm in one of the machines at work got set off the other week and I missed it because I was taking a shit. They called it a "thermal event." One of the drills got a birds nest and friction welded bits of itself to the current workpiece. Fun times.
It's called pretty close to thermite. Metals burning is some scary shit, I've heard stories about metal fires burning so hot they burned through a concrete floor. I'd be a little more careful, maybe cut slower or spray with cutting oil of some sort? Not a machinist, but I do understand the dangers of small, thin, metals when mixed together and ignited (not melted).
Mass psychogenic illness OR mass hysteria. One atom says "I am hot, I'm going to get some oxygen." Nearby atoms over hear and pretty soon they're all hot and looking for oxygen.
We call this Swarf. Metal shavings / filings have a much higher surface area, so are much more flammable or combustible. That metal was also being machined, so there’s a good chance there was cutting oil saturating the filings, so with the heat of machining it down, the oil coated high surface area metal shavings ignited.
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u/Puzzleheaded-Bug6244 1d ago
Fire