"Really don’t try this at home"

<MontyPythonVoice>"Oh, you're no fun anymore!"</MontyPythonVoice>

The thermite video is from a British-produced cable/satellite programme called Brainiacs, with commentary from Richard Hammond, who is sometimes referred to, on the motoring programme Top Gear, as The Hamster.

This is why, when I was a boy, my father adamantly refused to buy me a chemistry set.

At least in the Nitrogen Triiodide movie, you can see that the feather they use to touch off the detonation is attached to a stick, rather than someone's hand. Hopefully it was a long stick.

Speaking of stupid Microwave Oven tricks, I recall an episode of mythbusters where they decided to take half a dozen of the thingamajigs from microwave ovens and build a "supermicrowave". It didn't do anything, but sort of made me wonder just how unsafe even "professionals" get sometimes.

wait a second, aluminium and rust gives you thermite? Cripes, all the soda cans in my junk heap of a car is just trouble waiting to happen...

wait a second, aluminium and rust gives you thermite? Cripes, all the soda cans in my junk heap of a car is just trouble waiting to happen...

The rust you need is black rust, not red rust. (Easy to do. Take a steel-wool pad. Burn it. What you get is black rust.)

The aluminum needs to be powdered aluminum. (Easy to do. Melt aluminum in an iron crucible. Allow to cool, stirring constantly.)

I just want to know, how the hell do they manage to transport any quantity of nitrogen triiodide, ever?

Take a steel-wool pad. Burn it. ... Melt aluminum in an iron crucible.

OK, if you don't hear from me for a while, it's not because the thermite experiment went bad, it's because I destroyed my wife's kitchen supplies and her favorite frying pan...

What discussion of Things Not To Try At Home would be complete wihout mention of George Goble and his, well, unique way of getting those perfect barbecue coals -- with the help of liquid oxygen. Remember, put the match on the charcoal before you add the LOX.

A long time favorite of mine. I plan to try this sometime when my wife is out of town. Or perhaps out of the country.

how the hell do they manage to transport any quantity of nitrogen triiodide

it's probably like transporting a critical mass of uranium. some assembly required. hopefully on site rather then en route.

The Wikipedia page has preparation instructions. "However care should be taken not to get any of the dust produced in your eyes, as this could be very harmful."

It also suggests mixing it with ethanol for storage. Better yet, don't store it at all -- just make as much as you're planning to use, on the spot.

Patrick, in theory, you transport it wet. In reality, you don't transport it at all.

In an industry that for many years routinely used hideously sensitive compounds as mercury fulminate and picric acid (though not as much anymore -- lead azide is the primary explosive of choice these days), this stuff was considered wa-a-a-y too sensitive. The typical demonstration uses a feather to set it off. Unfortunately the instructions to make this stuff are fairly easy to find.

In FF, Heinlein's protagonist used gunfire trigger his charges. He would have been just as sucessful thowing rocks at it. Pebbles, actually.

Ah, memories of high school chemistry:
(lab partner) I think that's what we're supposed to do.
(me)hey, Mr. Chemistry Guy, is this supposed to glow like this?
(Mr. Chemistry Guy) Everybody out of the lab!

Heee! Things going boom!

sigh. Okay, back to work I go.

In the interest of spreading the Erisian virtues of Go Fast, Blow Stuff Up, and Don't Leave Anything to Bury, the above-mentioned TV series "Brainiac" runs on the cable channel G4 (g4tv.com). The "official" slot is Monday at midnight Eastern, but as is usual for G4, there are frequent reruns, usually in one-hour blocks of two eps. Next repeat appears to be Saturday at 7pm EDT.

It's one of the few things left on the channel worth watching, unless you're really completely desperate for Trek:TNG.

We made a tiny little bit of nitrogen triiodide in chemistry lessons, then upset the cleaners by sprinkling it on the floor to scare the first years when they stepped on it.

More memorable was the time one of the teachers made some for use the following day and left it to dry on the radiator. Unfortunately she'd made 10 times as much as she planned on, neatly demonstrating to everyone within earshot the importance of checking your units.

Nitrogen Triiodide is easy to make, and was the source of lots of pranks at university, but only make very small quantities. Putting it in someone's lock was a popular one.
I remember the discussion of this class of compounds in Partington's splendid old Inorganic Chemistry textbook ending with 'the discoverer of Nitrogen Trichloride lost 3 fingers and an eye'.
Safer fun is dipping people's cigarettes in LOX so they burn down rapidly when lit (much nicer than nitrating the tips).

Wow, it's Chemistry Week! I just encountered the Wooden Periodic Table Table yesterday. (Some of the elements are almost as scary as these experiments...)

It's not chemistry, but I've admired this minigun video for fun-to-watch destruction.

I haven't listened to it with audio on so I take no responsibility for what they're saying.

Ahhh, the memories. Sprinkling nitrogen triiodide crystals on the floor was practically an annual event in my HS. Topped only by the kid who managed to create nitroglycerin - or possibly by the kid who spilled hot nitric acid on his jeans, and was told by the teacher "Quick! Run home and change before it eats through!" (Yes, I was there. Yes that quote is indelibly etched in my memory.) The kid in question lived across the street from the HS, and broke all land speed records for the 200 yd. dash, shucking his pants as he went. We had an interesting HS chemistry lab.

This has continued in my adult life, as I stumbled in my job as a lab assistant into roughly three liters of dried picric acid, sitting on one of our storage shelves. It had leaked out of its container, spread out across the shelf, and dried. The hazards people said, oh so helpfully, "Be sure to wet it while you clean it up." My husband (a chemical engineer) said, oh so helpfully, "Get behind a heavy table, and chuck pennies at it." It was a fun afternoon, but nothing blew up.

I've been having great fun reading through William Gurstelle's ADVENTURES FROM THE TECHNOLOGY UNDERGROUND -- how to build all sorts of dangerous things. ISBN 1-4000-5082-0. Check it out.

Am I the only one who suspects that Heinlein, or an alert and cautious editor, decided that giving the CORRECT instructions for making an unstable explosive, particularly in an adventure story, might be a really, really, bad idea?

(The use of gunpowder as a detonator would probably discourage some of the complaints from "I will SO try this at home" types, when they couldn't get their product to function as advertised.)

As I recall, Jack Williamson described an early correspondence with an engineer about rocket designs. Sadly, it came to an abrupt end when the man was killed in an explosion. Williamson was relieved to learn, through L. Sprague de Camp, that at least it had nothing to do with rocketry. Just a co-worker being a little careless with picric acid.

There are some rather terrifying, but funny, anecdotes about the handling of explosives and detonators to be found in Gerald Pawle's account of British developments in "The Secret War" (1957), which Ballantine re-issued in 1967 as "Secret Weapons of World War II." Nevil Shute, who provided a Foreword, was, as N.S. Norway, one of the engineers involved in some of the projects. Although not, as I recall, with the bullet-proof armor plate which could also serve as a bulletin board.....

It was a fun afternoon, but nothing blew up.

Damm -- well aged dry picric acid is usually quite obliging. And I don't think the Hazmat folks of my aquaintance would have given you the same advice as your hazards people. Something more along the line of completely evacuating the building first.

In case anyone isn't watching Mythbusters yet, I'll just mention that they have (1) made a jawbreaker explode (2) painted a room using explosives (3) blown up a cement truck just for the hell of it (4) made a rocket out of salami. Must-see TV.

The salami rocket segment was interesting.

They were using a hollowed out salami as the fuel grain in a hybrid rocket motor. The oxidizer was nitrous oxide.

Conventional model rocket hybrids use a chunk of rubber or hard plastic for the fuel. I've read about amateurs who used LOX oxidizer and a roll of old carpet for the fuel.

* * *

You know the repugnant TV show where two families swap moms / wives? ("Wife Swap"? I really don't know the title.)

The producers have been trolling the model rocket community for a family of rocket dweebs to participate in a swap. I'm assuming the rocketeer family would get a cautious soccer mom.

UGH!

Ian Myles Slater:

There was a TV movie made in the 1980's that showed, step by step, how to make nitroglycerin in the bathtub.

I'm sure you can guess what happened...and the next time that TV movie aired, that particular sequence was nowhere to be seen.

IIRC, some of the things shown on _Macgyver_ had a step left out so the 'let's try this at home' crowd wouldn't be able to duplicate them.

It may be chemical folklore, but I recall reading that tri-iodide left entirely alone in a dry state could detonate from its internal structure compressing.

The Mythbusters "Confederate long-range rocket" was interesting, though some curious things were omitted (besides certain components of making guncotton and other boomy delights). They mentioned Hale rockets, but not Congreves, which the Confederacy actually did use in combat once (without much effect).* And their hunt for an oxidizer that would have been available to the Confederacy omits an extremely obvious possibility, though maybe for extremely obvious reasons. (The rocket scientists in the audience, professional, amateur, and "woo, lookit that," will know the compound I mean.)

But then, I've done more than the average amount of reading about ACW weapons, and I've never once seen a reference to the Vee-numero-two-oh. I'm curious about the source.

*I've probably told this story here, but one of Jackson's aides recorded that "some English chap had gotten it up for the occasion." Those of you who have read Flashman at the Charge will be able to put two and two together.

I suspect that you are right about the show; there were a few cases in which I thought something had been skipped over, or were just not shown in sufficient detail. Others just left me confused.

I seem to have missed that movie. I wonder how many people taped the original showing? That would have been more likely to have created a persistent problem if it was first shown in the middle or later eighties, I would think.

Dorothy Sayers seems to have garbled at least one murder technique, in "The Dawson Pedigree" (otherwise "Unnatural Death"), and it has been suggested that this was out of concern for providing an instruction set for the criminally-inclined. (Apparently even the correct instructions wouldn't have worked nearly as reliably as implied in the novel, either, but still would have put people at risk of at least injury.)

The possibility of a novel serving as someone's how-to manual has been raised in fiction, although I don't think I have heard of a confirmed case in reality -- perhaps "true crime" and other actual or supposed non-fiction fill the gap for the experience-challenged but literate would-be homicide.

I just want to know, how the hell do they manage to transport any quantity of nitrogen triiodide, ever?

You don't. My dad has a very entertaining story about a classmate who tried to produce gram quantities of the stuff in college. He kept all his body parts. The *instructions* were to produce it in IIRC no more than 0.1 g quantities.

It may be chemical folklore, but I recall reading that tri-iodide left entirely alone in a dry state could detonate from its internal structure compressing.

That's what happened to dad's classmate. Large (for NI3) mass, dried unevenly, and *boom*. He might've had less trouble if he'd spread it into a Very Thin Film, but then again, that's a lot of explosive... Keep in mind that in order to produce it, you have a wet solid, and that water molecules will disturb the solid as they evaporate. Eventually you'll have enough dry NI3 that just evaporation is enough energy to make it go boom.

The Confederate Rocket segment also had explicit bleep-overs where the guys when discussing ingreditents. The producers are covering their butts.

I have a great book on making small black powder rocket motors. (I'd call them "model rocket motors," but legally they can't be without immense amounts of legal and paperwork.) The author takes immense pains to explain everything, including the R&D he went through to come up with fuel mixtures, binders, nozzle materials, etc. It's mind-boggling comprehensive and straight-forward. I have no doubt that if I had copious free times, several acres of open land, understanding neighbors, and lots of up-front money for equipment, I really could make, for a few pennies worth of materials, working rocket motors.

But some of the things you have to do to get ingredients sounds like Meth Lab techniques. One chemical has to be leached from the goop found inside of Gopher Bombs with ammonia and dried on cheesecloth.

One of my writers, retired military, put in a notice at the beginning of one of his novels saying that certain essential steps had been left out or misrepresented, because he wasn't going to give the general public instructions for doing what gets done in the book.

As I recall, Jack Williamson described an early correspondence with an engineer about rocket designs. Sadly, it came to an abrupt end when the man was killed in an explosion. Williamson was relieved to learn, through L. Sprague de Camp, that at least it had nothing to do with rocketry. Just a co-worker being a little careless with picric acid.

This sounds like it must have been Jack Parsons. He was a fascinating figure, a pioneering rocket scientist as well as a dabbler in the occult, and was acquainted with many sf people, including Heinlein and L. Ron Hubbard, who supposedly ran off with his girlfriend. I've heard various descriptions of the fatal explosive; the bio I read said it was an entire coffee can full of mercury fulminate.

My high school chemistry teacher, Harold F. St. Aubin, used to say, in his deep Kentucky accent, "People, always remember: Just 'cause a little'll do a little good, don't mean a lot'll do a lot o' good." I recalled this advice many times in the 1960s, and even heeded it sometimes.

One time when I didn't heed it was when I was alone in the h.s. chem lab and decided to follow the experiment where you made iodine crystals by heating up some compound, producing iodine vapor that you condensed onto ice. Only for some stupid reason I doubled or tripled the proportions, resulting in my filling the lab with beautiful violet vapors. Fortunately they dissipated without too much trouble.

The rust you need is black rust, not red rust.

Iron (III) Oxide, aka Ferric Oxide, aka Hematite, aka Fe2O3 aka Rust works just fine in a thermite reaction, namely...

2 Al + 3 Fe2O3 -> 2 Fe + Al2O3 + 851Kj/mol.

... or more proasically, 2 Aluminum + 3 Rust becomes 2 Iron + Aluminum Oxide + bizzare amounts of heat.

It is easier to start the reaction with Iron (II,III ) Oxide, aka Ferrous Oxide, aka Magentite, aka Fe3O4, aka black rust, but you only get 768Kj/mol.

The aluminum needs to be powdered aluminum.

Nah, pellet aluminum works great, and is much easier to handle safely. It does make the thermite harder to start, but our standard trick to that is a small dash of Special Sauce (powdered magnesium) and a sparkler fuse. Powdered aluminum is very flammable and powerful -- it's the fuel in the Space Shuttle SRBs (with ammonium perchlorate as the oxidizer, and Iron Oxide as a catalyst -- yep, there's a little bit of thermite there....)

In particular, the various "dark" powdered and flake aluminums are something to stay away from unless you know exactly what you're doing, and even then, consider carefully. They're touchy. Indeed, I don't even like messing with flash powder, which is far too willing to go off for my tastes.

Thermite is acutally very useful for welding rails together. Otherwise, I find it best consumed 1500 pounds at a time. Every state should have a volcano, and if your state wasn't issued one, make one.

Iron Oxide isn't the only reagent you can use for the thermite reacion. Copper (II) Oxide (Cupric Oxide, CuO) works very well, and leaves a hunk of pure copper, rather than iron. Alas, I really suggest not doing this, the smoke produced by the reaction is really nasty stuff. Theoretically, Beryllium Oxide would work as well, but PLEASE don't go there.

Hmm, Eric, how about uranium oxide? Yellowcake (U3O8) + aluminum oxide + ignition = ? Uranium dioxide is rather flammable by itself.

The colors definitely would be pretty, and there really shouldn't be anything besides chemical reactions (and the odd alpha particle) unless you buy your uranium oxides from some rather bent people.

Why are the words "spontaneous bulk detonation" running through my head?

Three... litres... of.. dried... picric acid...

[squeaks faintly]

I wouldn't even have it in my lab. There were alternative etches, and that stuff scares me even in 50ml dropper bottle size. If I really had to use it, I went next door to the people who used it regularly.

On the other hand, some years back I sent off for the HAZMAT data sheets on some of our routine use materials as part of a general safety spring clean. And when I discovered exactly what we'd been innocently harbouring, the next thing I sent off for was a much bigger and explosion-damping fire-proof chemicals cupboard suitable for those things that are perfectly harmless at room temperature but not the sort of thing you want to be standing next to in a fire. And a couple of "WARNING: and we really mean this!" signs for the door.

Reminds me of when I my group were sharing a lab with some laser optics people, due to building work. We had terrible trouble convincing them that the code locks on the doors were there for a reason, and propping them open was a really, really bad idea. Giving one of them a quick but detailed tour of the contents of one cabinet picked at random made quite an impression, though.

Now, when chemical engineers play, the results are much, much, much larger. Chip fabs have bulk quanties of stuff that will etch and react with silicon and glass. At the same time, the environment surrounding the machines which carry out the processes must be kept awesomely clean, with a steady downdraft to keep the dust down.

I'd really like to design one which looked like a Borg cube, sometime.

The simplest method of making thermite I've heard of is storing powdered aluminum in a coffee can in the refrigerator at work. Think condensation. I'm not sure which engineer thought it was a good idea, but I know they had to replace the fridge. And some other stuff.

My husband got to make ammonium triiodide in high school. Samples of it were drying on a shelf just under the classroom bell when it went off. He said they didn't paint over the scorch marks on the wall for a few years. That was the chemistry teacher who was missing at least part of a finger.

Ian Myles Slater:

The possibility of a novel serving as someone's how-to manual has been raised in fiction, although I don't think I have heard of a confirmed case in reality

There was the night-deposit-box scheme in Neil Gaiman's _American Gods_ that may or not have been inspiration for a robbery in Winnipeg. Neil wrote a bit about it at the time; a couple of posts later he provided a link to an Edmonton Journal newspaper article but their archives seem to have gone the way of the dodo.

And their hunt for an oxidizer that would have been available to the Confederacy omits an extremely obvious possibility, though maybe for extremely obvious reasons.

You mean the one ChemTech quoted a rude poem about, ~29 years ago? They claimed some poor sod was sent around to collect the ... raw materials ..., and was satirized by a local rag; I've wondered whether any of the verses were authentic.

For some reason this thread reminds of my father's work-and-fishing buddy McLeod, who was a pyrotechnics guy. I understand at one place he worked he found someone had detonating cord stored in a desk drawer around the corner from a swaging operation. He took it away from the wannabe-victim - and put it in his desk drawer. (No, he died of other causes many years later.) He also had stories about various azides and other things that go bang.

PJ, your story reminds me of my first introduction to realistic discussions of high explosives. My high school drafting teacher was in EOD as a Marine in Korea. He had some interesting stories about how useful Primacord could be in handling all sorts of everyday tasks. The descriptions of the more coloful ways of disposing of excess napalm were fun too.

He must have been good -- he still had all his fingers. Of course in military EOD, you're rather lucky if a mistake costs only a finger or two.

I knew a guy in college whose high-school chemestry classes were quite fun for awhile. Someone in the class had read From the Earth to the Moon and the interesting instructions therein and his class proceeded to use them. Successfully. The fun and games stopped after one of the kids decided he liked an earlier experiment but wanted more. He made a block of Nitrogen triiodide that weighed an estimated four pounds and decided to sneak it out of the lab and back home inside his nylon windbreaker while walking across a grass field. I understand the extremeties stayed in place, but the torso was, er, well, emmm...

Then there was Uncle Phil. Uncle Phil worked at McDonnell Douglass. He was very much a "show me" guy. When he heard that magnesium would burn underwater he took a five-gallon coffee can to work and filled it with magnesium chips from the shop floor. He put the can in the driveway at home and filled it with water, covering the contents with the exception of one chip that he left poking above the surface of the water. He then poured a tablespoon of gasoline on the surface of the water to act as a fuse and threw a match onto the film of gas.

He learned several things. He learned that the flames from burning magnesium in a five-gallon can of water will go up over six feet but under ten feet. He learned the water will keep the can cool enough that the joints will not melt. He learned that the can will get hot enough that the asphalt under the can will melt and run down the driveway. And he learned that the L.A.F.D. does not care if you're using your own can, your own chips, your own driveway, and are on your own damn property--they will chew your ass up, down, and sideways when the neighbors call in (and count upon it, they will) a report.

I think of this every time I look at our backyard, which some previous houseowner paved over entirely, and try not to consider how much cheaper Thermite would be than setting up a furnace for metal casting. My wife thinks of this every time Jon Singer send me one of his "Wow, Bruce, this is neat!" e-mails, complete with links.

Er, um - the aluminum stuff. I have aluminum leaf (better than silver leaf, as it doesn't tarnish) in my studio. Do I need to worry about anything? Besides my experimentally minded husband I mean. (I do have a variety of iron oxides around.)

As an artist I do pay some attention to chemicals, but I worry more about poisoning myself, or pictures fading or changing color, than blowing stuff up.

Jules,

we used to keep liter quantities of picric acid around for fixation of biological samples prior to electron microscopy. It's not so bad, provided that you keep it hydrated. Osmium tetroxide and uranyl acetate, on the other hand... eeeeeew. Unavoidable if you do EM, but *yuck*. And my dad has some extraordinarily funny stories about nitrogen triiodide, metal-bodied liquid-fueled rockets, and other explodables. He quit playing around when a university lab instructor (at Purdue, home of the world BBQ-prep speed record referenced above) displayed a jar containing formalin and fingers that had once been attached to an adventurous but careless undergrad...

Yep, three liters. The sad thing is that they weren't even my three liters. It was left over from the researcher who'd used our lab before. Nobody had cleaned out that shelf before I took a look at it (I wonder why?).

Our hazards people were lovely folks. Refused to do anything but tell me to clean it up because it was my lab, and hence my problem. Nothing to do with them being a nice, safe, three buildings away, I'm sure.

These were the same people who had fits because I would use the spectrofluorometer without gloves (they ruined my injection timing), while using Ringer's solution. What if I spilled it on myself? I considered waiting until the inspector was in full rant, and then simply drinking down the beakerful, but never gave in to the impulse, more's the pity.

My husband reports that an M-80 with a waterproof fuse has interesting effects when dropped in an above-ground pool.

Somewhere around here I think I still have some pictures of Roberts "blowing up the coolie closet" on MIT's 3rd East East Campus when I was an undergraduate--janitor's sink in hall closet (adjacent to the trash chute) thermite, cord, butane, light cord with Zippo, shut closet door, shortly there after the closet door flies open and a fireball flies out. Roberts also used to do the mouthful-of-butane, light match in front of face, blow gas from mouth, flame trick--he singed his moustache being a bit careless doing it once. He also had a black powder miniature replica cannon which he fired a blanks shot out of a dorm window--once. The campus cops showed up post haste after the blast noise, and a quicktalking barracks-lawyer sort explained that black powder replica cannons weren't covered by MIT's then-extant firearms restrictions. "We'll let you get away with this -once-" said the campus police.

Some other folks in the dorm occasionally would send up exploding balloons out of the dorm (flammable gas, and ignition device.) And then there were the waterfights, which were a different issue... one year there were so many waterfights in the Goodale end of 3rd East that a mushroom sprouted where the carpet pulled away from the wall.

Alexey: I don't think picric acid would have bothered me as much if it had been something I used *regularly*, and not just for "familiarity breeds contempt" reasons. But it was something I didn't have any particular need for more than about once a year, and given a choice between things that will just eat the bench if spilled and left, and things that will go bang, I'll opt for things that eat the bench. Especially as we did not have high security locks capable of keeping out nosy security guards looking for tea and biscuit supplies.

The one that made me back away hastily and call the site safety manager was going to the bulk chemical store outside to refill the lab-size bottle of acetone, and discovering someone else's *broken* bottle of something that should have been in the radioactives store, its fine crystalline contents scattered all over everyone else's flammable/explosive/toxic/otherwise-excitable-in-bulk containers.

I have aluminum leaf (better than silver leaf, as it doesn't tarnish) in my studio. Do I need to worry about anything?

Nope, you're safe -- the shiny stuff is fine. And to be pedantic, it does tarnish -- in fact, it *has* tarnished. Aluminum's great trick is that it almost instantly becomes Aluminum Oxide (AlO3) when exposed to oxygen, and Aluminum Oxide is both very tough and very non-reactive. Thus, all the "bare" aluminum you see is actually a very thin coating of aluminum oxide.

Aside: How to ruin aluminum. Mercury. Aluminum is soluable (barely) in Mercury. If the mercury can get beyond the oxide layer (say, by a scratch), then it will start dissolving the aluminum, and the mercury will keep the aluminum oxide from reforming until it is ontop of the mercury, thus forming dust, rather than a supported film of oxide. If you've ever looked carefully at the list of things you don't bring on airplanes, you might have noticed "Mercury Thermometers". This is why.

Dark flake aluminum has a coating that keeps it from oxidizing. Shiny leaf Aluminum will burn -- then again, so will many metals ground fine or rolled thin (take a torch to steel wool, if you wish, or better, put it in a microwave. I suggest Somebody Else's Microwave.)

Offhand, I don't know the combustion products, so a good rule remain "don't breath the smoke", but it is possible that burning aluminum ranks with either copper (You really don't want to do that,) or Zinc (Bad!) or Beryllium (BAD! BAD! ARE YOU NUCKING FUTS!). I think it was Jordin Kare who, in a rather evil thread on sci.space, suggested a shuttle using Liquid Hydrogen/Fluorine for the main engines, and Beryllium/Uranium Hexafluoride as the solids. Launch pad reuseability poor, along with shuttle reuseablity, and probably astronaut reusability. Certainly the kind of launch you'd only see once.

I would suggest not grinding it up and mixing it with Ammonium Perchlorate, but there's *lots* of things that advice applies to.

Hmm, Eric, how about uranium oxide?

(s/Eric/Erik)

Hmm. I don't know. I don't have the chemistry chops to figure it out from just the reaction. It's clear that UO2 and UO3 won't -- the first thing they do when they start to get warm in the presence of oxygen is become U3O8. I really don't have any knowledge of how the Actinides react. I do know that uranium is pyrophoric, which implies that it wants oxygen -- so it might be a pissing match between the Al and U for the free oxygen. If it did work, the pyorphoric reaction would provide an "interesting" secondary source of heat.

Also, a large mass of (233)U3O8 or (235)U3O8, if able to use the thermite reaction, would have a very interesting third source of heat at the end. I suggest watching from Somebody Else's State.

I note that most of the elements that work in the thermite reaction tend to be much lower in the periodic table, but I suspect this datapoint comes from cost concerns. Theoretically, since Iron and Copper work well, Ruthenium and Silver would as well, but I've never seen several ounces, much less pounds, of the oxide lying around. Heck, anymore, Copper Oxide just costs too much. Magentite and Hematite is trival to find, heck, if you're in any areas that are known for iron mines, you can probably find it lying around nearby.

A few years back, I boarded a horse at a busy stable. Another boarder:

1. Was a chemist
2. Was a wanna-be cowboy
3. Wanted to compete in mounted shooting, which is where you ride a horse at breakneck speeds through an obstacle course and shoot at balloons with a handgun loaded with ground corncob. This is great fun if your problem isn't:

4. An extremely silly horse who was terrified of loud noises.

The chemist decided he'd get his horse over the fear of loud noises using noisemakers he'd made. I never asked the compound at the time, but he put a pinch of the compound into a tissue and wrapped it up securely -- he had about two dozen little twists of tissue in a pocket he'd sewn on his chaps.

So this guy gets on the horse, and throws the first twist of tissue on the ground next to the horse. The tissue goes, "Crack!" and the horse blows up as well.

The wanna-be cowboy lasted a good bit less than eight seconds. He hit the ground hard -- right on top of the pocket containing his little tissue-wrapped explosive noisemakers. Fortunately, he had on heavy leather chaps. Unfortunately, he still had quite a bruise and a bit of a burn to show for it.

As I recall, he never did get that horse over being afraid of loud noises.

Leva

I never asked the compound at the time, but he put a pinch of the compound into a tissue and wrapped it up securely...

Very likely red phosphorus plus potassium chlorate and a little bit of gravel.

It's the same mixture that you use in cap guns.

My father and some of his colleagues were apparently into building model rockets, in the late 1950s when he was an apprentice at the Newport News Shipyard. I never actually heard anything about this from him before he passed away, but I heard all sorts of stories from one of his old friends.

Apparently their finest moment was when they built a rocket with a solid magnesium nozzle (or possibly it was an entirely magnesium rocket; I'm not completely sure) and launched it late at night from the beach in front of the commanding officer's house.

Jacob, there's something that looks odd about that minigun video. Where there's closeups of the actual gun, there's no apparent rotation of the barrels and the muzzle-flash seems to be coming out of the central axis. Also, I don't see any sign of recoil affecting the vehicle it's mounted on.

Apparently, one reason the Confederacy was able to keep fighting for so long was that they built their own gunpowder factory, and it didn't blow up.

Picric Acid: I gather that it's the metal salts that are the really nasty stuff. Also known as Lyddite, it was used as a shell filling. Read here about the problems of AP shells. It's in the second section of the page.

Obviously, you need some barrier between the shell casing and the filling, but French farmers are still ploughing up WW1 duds, and not blowing themselves up. And advertising this farm could be difficult.

We made the bleach and iodine explosive in high school chemistry. We also made gunpowder. I suspect that today kids aren't taught that kind of thing.

I suspect that today kids aren't taught that kind of thing.

Well, when I was in high school chem (which was during the Nixon Administration) there were definitely not any experments (or even demonstrations) of explosives. There was, however, a specific-heat experiment, to be performed by the students, that involved dropping a bit of sodium into a large test tube full of water. The students were instructed to use a piece about the size of a pinhead. Of course, almost without exception they assumed that the task would be much simpler if they tossed in the largest piece that would fit in the tube.

This led to many interesting moments, and the rapid disappearance of sodium from the front shelves of the lab. It would reappear, quite as if by magic, in sinks and toilets throught the building.

(I was one of three guys who spent the class in the back of the house, getting the stuff ready for the teacher, so I merely had to help clean up after all this. We had all the really bad things back there, and never talked about them, or indeed did anything with them, because most of them had no application to one-year high school basic chemistry. In fact, because for years the previous instructor had put in a standard supplies order whether he used the stuff or not, we had enough hydrofluoric to have scared a hazmat team.)

The User Friendly take on this subject

The User Friendly take on this subject

*Wakes up, staggers out of bed.*

*Goes to kitchen*

*Opens pantry, takes out can of self heating coffee*

*Opens back door, opens can of self heating coffee, throws can out back door.*

*BOOM*

Nothing like that first coffee to wake you up in the morning.

I seem to remember that Tom Clancy made a point in the foreword of The Sum of All Fears of stating that the meticulous detail on how to make an atom bomb given in the book was wrong in one or two details, so that no-one would be able to follow the book to make their own bomb.

As I recall, the first step was to secure a misplaced Israeli bomb....

Hydrofluoric acid - now that's the stuff that scares me silly. My materials science students have 24/7 access to the lab once they're trained (SEM/EDS, XRD, DSC, FTIR, Instrons, impact testers, furnaces, and all) but using HF to etch metals is one of the very, very few things that they aren't allowed to do unless I'm around, have read them the riot act, and made sure they know where the HF antidote is.

For those of you who are unfamiliar with HF, there's a nice (and by 'nice,' I mean 'terrifying') summary of the effects on Wikipedia.

debcha - So what's the remedy for HF exposure? I'm assuming that it's something non-obvious.

Thanks for the link. I knew the stuff was dangerous, but I had no idea of exactly how dangerous until now. Yet another reason to steer clear of laboratories.

The other problem with hydroflouric acid is that is it, I hear, produced in fires involving fluorocarbons, such as can happen to a wrecked car. Here in the UK, it's quite common for stolen cars to be dumped and set on fire.

The 'antidote' that I mentioned is a calcium gluconate gel, which you apply to the affected area as you are booking it out of the lab and towards the ER. The really, really dangerous thing about HF - well, aside from the fact spilling it on your skin can actually kill you, not just give you a nasty burn - is that, with solutions of less than about 20% HF, it can pass through your skin and start dissolving your bones without you noticing (the pain comes later). If that's already started to happen, or the amount of HF is high, you use an injected calcium solution instead of/in addition to the topical gel.

Erik V. Olson said:

"Also, a large mass of (233)U3O8 or (235)U3O8, if able to use the thermite reaction, would have a very interesting third source of heat at the end. I suggest watching from Somebody Else's State."

Actually, the experiment should be conducted in Somebody Else's State, and watched from Yet Somebody Else's State, thus leaving yours a Steady State (theoretically).

Ah, the old nitrogen triiodide; the mere mention of it is enough to bring a tear to the glass eye of this erstwhile schoolboy.

How fondly I remember the day we applied some, moist, to the gown of a maths master after he had taken it off and hung it on the back of the classroom door before going to lunch. A man of habit and religion, on his return he shook the gown as usual to remove any chalk dust before putting it on.

What a rare treat it is, what a privilege, to witness a person undergo a surreal moment so transformative. A man may live to a great age without experiencing self-detonating vestments, but Horace Greasley, M.A. (Cantab) could thenceforth never make that claim. He began the lesson without comment, his enthusiasm for binomial expansions seemingly having deserted him as he droned on, staring straight ahead for the most part, but with an occasional nervous glance towards the heavens.

The thermite reaction has actually been (and is still used, I think) for the production of pure uranium metal, though I think they start with UF4 instead of a uranium oxide. They also do it in closed containers, which probably makes it a little less exciting to carry out. It's called the Ames Process, because it was developed at Ames Laboratory in Iowa during WWII. There's some info
here, under 'commercial and industrial uses', and a bit more here on pages 313
and 314.

The thought of that having that reaction go wrong is...unnerving.

(How do you get links to format correctly, btw?)

(How do you get links to format correctly, btw?)

The format for an embedded link is in the list of "HTML Tags" just below the Preview button. Put the URL where it says "http://www.url.com" -- do not omit the quote marks or the http:// -- follow the close quote with a right angle bracket (>) and the words you wish to appear highlighted as the link in text, and conclude with the bracketed not-a command. A line break may appear in the text box after the bracket-a command, but will not show in the finished post. Go to Preview and mouse over the link text to make sure it displays the correct URL, and if it does, go to Post.

Is that the information you wanted, or is there some other problem?

The problem I had wasn't in making working links, but rather in getting the line breaks in the posted message to work well. I think this happened because the html tags for the links took up a lot of room in the message and affected the appearence of the finished post, and I'm not sure how to deal with this. Any thoughts?

Dave: The other odd thing about the minigun video is the use of tracers. Most places they are illegal, which means they are expensive, and even assuming the 1/20 ratio it looks to be, that's a lot of ammo going downrange.

They also claim it's the fastest gun in the world, at 3,000 rds per minute, which ain't true.

The Whoossh bottles are similar to the "fire genies" we used to make (and I expect to make again) using rubbing alcohol.

Different shapes of bottle make different tones (and have different behaviors when the oxygen is semi-depleted).

The effect of a sheet of pale blue flame drifting down a five gallon bottle is beuatiful.

TK

The thermite reaction has actually been (and is still used, I think) for the production of pure uranium metal, though I think they start with UF4 instead of a uranium oxide.

Well, if oxygen isn't reactive enough, you reach for Fluorine. (Kids. NEVER reach for Fluorine. Hydrofluoric acid has this very nasty property of passing through your skin and eating your bones. I'm not kidding.)

One of the reasons Aluminum does so well is the very wide spread between the melting point and the boiling point. The higher the melting point, the easier it is to get a high temperature from all the heat, since you avoid heat of vaporization issues. Low melting points mean the reactants are mixing with liquid, which allows greater contact.

The source you quote mentions "bomb reduction in calcium." So, apparently, we're looking at (and this is guesswork, chem was a long time ago) UF4 + 2 Ca -> U + 2CaF2 +(X)kj/mol, where X is unknown. Since it is a bomb reduction, I'm safe in presuming X is positive.

CaF2, better known as Fluorite, is also a very stable compound, not as stable as Aluminum Oxide, but Fluorite is a pretty common mineral (and is the common industrial precursor to the above mention Hydrofluoric Acid -- CaF2 + H2SO4 -> CaSO4 + 2 HF, or Fluorite + Sulfuric Acid -> Calcium Sulfate + Hydrofluoric Acid. Calcium Suflate is better known in nature as Gypsum, and to artists and the like as Plaster of Paris. I digress.)

Calcium metal melts at 842C, boils at 1484C. Aluminum melts at 660C (one of the lowest points of the structural metals) and boils at 2519C.

Uranium and Iron's boiling points are higher, so it's the heat of vaporization of Calcium and Aluminum that really limit the reactions. So, you're looking at no more than 1484C for the UF4 + Ca reaction, there's plenty of reaction vessles that can withstand that temp. Thermite can easily reach the boiling temp of aluminum, nearly 4600F, and there isn't much that can take that high a temp. Worse, there's all the heat being generated by the reaction, so it stays hot. This is why thermite melts through things -- it's at a high enough temp to melt something, and has enough heat to stay molten and flow through. Heck, it has enough heat to acutally vaporize the aluminum -- heat of vaporization for aluminum is 294kj/mol, while the reaction is putting out over 800kj/mol, so if you have enough insulation, or enough thermite, you'll bring the whole mass of aluminum to the boiling point, with enough energy left over to vaporize some of it.

(Stand upwind of burning thermite. This should be obivous.)

What I don't know, and don't know how to figure is how much heat is released by the UF4 + Ca reaction. If the heat is low, then the reaction is easily containable. I suspect that it does release a fair amount of heat, but nothing like the classic Iron Oxide/Aluminum thermite.

cool video, pack that aluminum/iron oxide stuff into a small little cube and add a better fuse and you can open any door/lock in the world! including back vaults :) :)

#73 looks suspicious to me.

Having looked back at the top-post, which predates my arrival here, I'd like to mention that "liquefying Pyrex" is nothing particularly unusual. One of the standard types of glass used by glass artists is effectively Pyrex. Now, if this guy is melting it some other way than with a torch, that would be different.

Dang, how'd I miss this post? RE: Picric Acid

I think I told this story before on another post, but it fits here, too.

At a previous job, I was the one in charge of periodically getting the hazardous waste haulers in to get rid of various expired epoxies, chemicals, and the like. On one of the various "clean out the desks/storage areas, we need more space" jaunts, I uncovered a cardboard box housing, IIRC, 8 liter-sized glass bottles that had apparently contained wet picric acid. It was ~10+ years old at that point, and nobody knew what it was for. I carried it over to the cube we stored the expired stuff in and stuck it on a shelf. Then I looked it up, as I was checking to see the most cost-effective way to get rid of the expired stuff.

Oh, dear.

The hazwaste hauler told me, after carefully packing each bottle in vermiculite in its own little armored over-pack, that I had enough dry picric acid to turn the entire block into a crater, and that I'd made him more nervous than the time he'd hauled sodium metal.

As for thermite, a buddy of mine said that he and his friends had improved on the basic mixture by compressing it into solid slugs using a hydraulic press. The slugs held together rather well, making a "goes to China" driveway-and-ground-beneath melter work a treat.

BTW, "Ignition!" is floating around on the 'net as a PDF, as is "Excuse me, sir, would you like to buy a kilo of isopropyl bromide?". Both are entertaining reads about chemistry in the "bad old days", the first about rocket propellants, the second about all sorts of interesting things.