How big a bang am I allowed to make without actually invading anyone?

December 20, 2007 8:36 PM

What's the largest explosion I can make, legally, without any particular kind of license, and what would I use to make it?

I'm specifically asking about Victoria, Australia, but my supplementary question is: Given the same legal conditions, where would I go to make that large, legal, explosion larger?

posted by pompomtom to Law & Government (14 answers total)

Are carbide cannons legal in Australia? Those can get pretty damned loud.
posted by Steven C. Den Beste at 8:54 PM on December 20, 2007

In most parts of the U.S. it's legal to buy black powder, although the Feds my frown on you assembling it into anything bomb-like, for obvious reasons. (And just sticking a fuse into a pile of it is somewhat unimpressive.)

I know there used to be a few states where you could buy dynamite as a private citizen, generally for removing tree stumps. I don't know what the regulations are on it now, although every once in a while you hear something mentioned about it on the news. I think they might have passed a regulation after 9/11 mandating that you show ID in order to buy it (one assumes to prove that you're a resident of the state where it's legal, and not an adjacent state). I did some quick Googling and didn't turn up much current information, though. Maybe someone will have better information.
posted by Kadin2048 at 9:14 PM on December 20, 2007

You can do a lot with dry ice.

If you know the why and the how of dry ice and loud noises, you will find you can do a lot of other things with various ingredients.
posted by bh at 9:17 PM on December 20, 2007

Do you want to do this in front of an audience or just make a big explosion?

If there's no loss of life or property, what's legality got to do with it?

Making explosives isn't illegal; using them to damage persons or property is.

Nitroglycerin isn't technically difficult to make if you have some wet-lab chemistry experience. The precursor chemicals aren't too difficult to find/synthesize.

I don't know Australian law, but buying dynamite can't be that hard.

Just get/synthesize as much dynamite/nitroglycerin as you can afford and set it off in the middle of nowhere.

Now, getting the best bang for your buck - you'll probably want to consult a munitions expert; to get a really big bang you don't want to have the materielle going off at different times: timing to get everything to go off at exactly the same time makes for much bigger explosions (you'll need to take into account timing and placement).

Oh - after re-reading; nevermind. you'll probably have more fun buying* and throwing 50 pounfs of silly putty off of a building.

*they ship pretty quickly and I love my lb of silly putty - I want to get a 10lb chunk eventually
posted by porpoise at 9:36 PM on December 20, 2007

Porpoise - Are you just trying to be an asshole? Or are you just that much of an idiot?

If pompomtom doesn't even know what can be made legally, do you really think that mentioning nitroglycerin is a good idea?

If you don't know why you shouldn't be playing with contact explosives, you shouldn't be playing with contact explosives.

There are plenty of ways to make a nice 'boom' without risking life and limb.
posted by bh at 9:50 PM on December 20, 2007

Making explosives isn't illegal

I think you'll find that in many Western nations these days, making any significant amount of many kinds of explosive is very illegal indeed, in a kiss-your-ass-goodbye, you're-on-a-plane-to-Syria-now kind of way.

Here in Australia, even the use of fireworks by the unlicensed general public is illegal in most of the country.

Unlicensed possession of serious explosives of any kind - including black powder - is an offense in Australia, and was before the Communism terrorism scare too. By extension, so is setting said explosives off for fun or profit, whether or not you hurt anyone or anything.

Which is not to say that there aren't plenty of big bangs that you can make relatively safely if you've got a couple of acres out in the bush with neighbours who don't care. Oxy-acetylene bombs (light oxy torch, set gas mix for blue flame, extinguish, fill big plastic bag with gas mixture, hope static electricity does not cause it to go off early and smash you to a pulp) probably give the best risk-to-result ratio, if you definitely want a big bang. Some novel ignition techniques are on display on YouTube.
posted by dansdata at 9:58 PM on December 20, 2007 [2 favorites]

2BLEVE
posted by jcruelty at 9:59 PM on December 20, 2007

I was going to suggest asking Dan about it, and here he is.

Rather than mucking with the bag-o-combustible material he talks about, that's why I suggested a carbide cannon. It's the same bang, but a lot safer.

As to making nitroglycerin, that is not for the faint hearted. One way of doing it produces so much heat that it sets off the nitroglycerin immediately. And as mentioned, nitroglycerin is a contact explosive, so if you're stupid or careless you'll kill yourself. Not recommended.

Here's something I was told about about 25 years ago, and I don't have the slightest idea whether what I was told was true: you take a concentrated solution of copper chloride and bubble acetylene through it. After a while, the bottom of the beaker will be covered with an insoluble blue powder. Shut off the acetylene, run the whole thing through a filter paper to separate out the powder, and then while it is still wet, take it out into the middle of a field and leave it there.

It's copper acetylide, and it's a really sensitive contact explosive, but not if it's wet. That's what I was told. Once it dries, however, nearly anything can set it off: BB guns, flies landing on it, loose grass blown by the wind.

Wikipedia says:

Copper(I) acetylide, or cuprous acetylide, is an inorganic chemical compound with the formula Cu2C2. It is a heat and shock sensitive high explosive, more sensitive than silver acetylide. It is a metal acetylide. It is similar to silver acetylide and calcium carbide, though it is not called carbide in literature.

Copper acetylide can be prepared by passing acetylene gas through copper(I) chloride solution in presence of ammonia.

Me, I wouldn't want anything to do with the stuff.

I really do think a carbide cannon is your best bet.

(Of course, you haven't told us what you think "explosion" means. Bang? Flash? or Crater? If you want to make big divots in the ground, that's an entirely different matter.)
posted by Steven C. Den Beste at 12:28 AM on December 21, 2007

The Canberra Institute of Technology used to run an introductory explosives course. It was allegedly run by some ex-South African special forces guy who allegedly said "there are three types of people who do this course, farmers who want to remove tree stumps, people who wanted to get into the demolitions industry, or people who just like blowing shit up".

Anyway you could give them a call on [phone] and see if they still run the course. Yes I know it's not in Victoria, but it's the only course I know of in Australia.
posted by flutable at 2:12 AM on December 21, 2007

To answer your question though, dry ice is legal - you just need a plastic container (normal water bottle) and water.

Put about 50 - 60% dry ice in the water bottle, pour water in to almost full - cap it tight and throw it away (or get away). It takes between 10 and 30 seconds depending on your mix, to go off.

We did it on a remote beach (in Portland, Victoria) last year - it left a small crater and made an incredibly loud explosion.
posted by strawberryviagra at 4:00 AM on December 21, 2007 [1 favorite]

We used to iron together dry cleaning bags to build our own mini weather balloons. We'd construct a simple igniter by taping an envelope filled with black powder and fuse to the side of the balloon. Then, courtesy of our college science department, we would fill the balloon with...hydrogen gas.
Seal it off.
Light the fuse.
Run away as the balloon would quickly lift into the night sky.

We were always amazed at how high the thing got before we saw the flash of the explosion and the delayed rumble.
posted by Thorzdad at 4:44 AM on December 21, 2007

Amonium Triiodide is an easy bang for a buck with fun purple smoke and made of simple household goods.

Warning: whatever it explodes on will be stained purple (my father used it to make an exploding toilet seat prank back-in-the-day and stained a professor's backside).

If used in large quantities (warning: unstable) it makes a pretty good pop. It's no Amonium Nitrate, but a good crack. Definitely not a weapon's grade explosives here, but good for pyrotechnics and pranks. When still wet it can be "painted" on a floor or stairs and causes pops bigger than bubble wrap when dried and stepped on.
posted by Pollomacho at 7:02 AM on December 21, 2007

Ah how I miss the old days... rural Virginia... Calcium Carbide tennis ball cannons (yep) (and lighter fluid will work in a pinch), soak the tennis balls in gasoline if you want some real fun. Gunpowder in a wine bottle sealed with wax with a model rocket engine igniter.. (yep) left a 2 ft. crater in the yard and put a hole in the neighbor's garage door. Dry Ice is cool, but Liquid Nitrogen is better, just an inch or two in a 2 liter bottle, cap it and *run away*. Cannon Fuse (sold at neighborhood Gun Shop), some Gunpowder, some Paper and Glue == instant giant firecrackers. Oh, and Swimming Pool Chlorine mixed with Gasoline and Sulfur will spontaneously combust after a while, hot enough to melt Aluminium.... don't do that. Surprisingly my only scar from childhood dangerous things experimentation is a big drop of molten aluminium on the back of my hand.

I'm lucky to have all of my fingers.
posted by zengargoyle at 7:09 AM on December 21, 2007

The physics department at my college held a physics fair every year. The grand finale was a liquid nitrogen bomb, but you can achieve the same effect with dry ice. We had to alert the local police department in advance, because inevitably neighbors around the campus would call to report the explosion.

There's no shrapnel (except for a 2 liter soda bottle), but the shock wave would rattle windows.

Liquid nitrogen goes into the coke bottle, you screw down the cap, and run away. Our professor put it in a big trashcan of water for maximum effect. The liquid turns to a gas, pressure builds up, and boom.
posted by spikeleemajortomdickandharryconnickjrmints at 7:52 AM on December 21, 2007