Thread: How to blow up a vehicle?

I'm working on a scene in my story where the guy blows up a car, but I don't know if simply pouring gasoline and igniting it would work. I used to have all the technical details of pouring it in an enclosed area to let the gasoline fumes ignite but it was too involved. Can ya'll tell me the best and simplest way to blow up a car?

Fuel is not a sure-fire means of blowing up a car. In fact, if the tank is full or close to it, it will ignite and not explode. Think about a puddle on the floor. Put a match to it and what happens? It ignites. It doesn't explode. It's only when there's a build-up of pressure (when the tank is near empty and there's a greater ratio of air to gas) that an explosion can occur. That's why fuel trucks are fitted with earthing devices which eliminate static pressure. After a long journey where the fuel has been rolling around inside the container, if you were to open the lid without proper earthing in place, you would be vaporised because of the static energy created by your body.

Those movies were you see an actor toss a cigarette into a car soaked in fuel and it blows up a second later, it's all bunk. Neither can you shove a rag soaked in fuel down the filter and light it. The tank would need to be full for the rag to reach the fuel, and we then come back to the aforementioned air-to-gas ratio. If the tank isn't full, there is a sufficient distance between the filter and the fuel to ensure the flame never reaches it.

Bullets don't work either. Mythbusters debunked that a few seasons back. There's no ignition when a bullet strikes the tank, so therefore no spark and no explosion.

You would need to bomb it. Have your character build an IED and mount it to the underside of the car.

Saw's right. Also, the fuel tanks are designed in a way that flames wont travel down them. The gas coming out of the nozzle might ignite, but it either makes a candle out of your fuel tank, or the burst itself puts the flame out.

If I could offer two suggestions for blowing up a car (reasonably), one would be flour, the other would be thermite. A little known fact is that flour is flammable. But it needs to be dispersed enough for the particles to ignite. With a small explosion you can both disperse and ignite a bag of flour with enough force to destroy a car. I first heard about it being used by terrorists to destroy buildings. A huge bag of flour over a smaller (and thus cheaper) explosive.

The second method is with thermite, which is a combination of rust (well cooked) and aluminium filings. Make sure the filings are very fine (the finer the better). Mythbusters use the stuff with some of their experiments. An amount the size of a large button will burn through the bonnet of a car, through the engine block, and into the pavement. You could have your hero place it over the fuel tank... and I would expect that such a hot substance would create an explosion out of the fuel; not that I've tried it. You'll need a small strip of magnesium to ignite thermite.. a simple flame, no matter how long you hold it there, will not work. This also means it's very bright, and you shouldn't look at the thing once it's live (akin to looking at the sun).


*Ahem*.. by 'you' I mean 'your character'

oh, hey! I saw an episode on Criminal Minds once where the unsub (unknown subject) uses a pressure trigger to set off the bomb, where Target sits in his/her car, and that pressure is connected to the bomb that's fixed underneath. It'll blow up when he/she leaves the car.

I think the Mythbusters showed that even if you aerate gas, it's still a pretty low powered explosive.

If you character doesn't have access to high-powered explosive, why doesn't he steal chemicals from a chemical plant?
Certain fertilizers works too.

Originally Posted by The Blue Pencil

I'm working on a scene in my story where the guy blows up a car, but I don't know if simply pouring gasoline and igniting it would work. I used to have all the technical details of pouring it in an enclosed area to let the gasoline fumes ignite but it was too involved. Can ya'll tell me the best and simplest way to blow up a car?

Dynamite. Light fuse, throw in window, run like hell. That will blow up a car everytime.

If you have already watched the Viewer's Special Requests episode of Mythbusters, you'll know that the only sure way to blow up a car is through explosives.

Just use some explosives to blow up the car but if another way must be used, just use a method that sounds feasiable even if it cannot actually happen.

I think riverdog is right. Dynamite works for everything. Or gunpowder.

Murphys weedkiller, icing sugar and flowers of sulphur mixed in the correct ratio makes a powerful explosive. And no, im not putting the correct ratio here! Fortunately if the ratio isnt right it wont do much other than fizzle and burn out so hopefully I havent fuelled anyones murderous imagination too much there!
all these are (or at least were when i was at school) available over the counter. An ignition system would be fairly easy after that, maybe a 12 volt supply to a car cigar lighter mounted where it would ignite the explosive, or just two wires with a thin fuse wire between which would burn out as soon as the key was turned, causing a spark to detonate?

Originally Posted by Schmitz56

I think riverdog is right. Dynamite works for everything. Or gunpowder.

Pipe bomb would be easy to make, remote detonation or trip wire to set it off. Gunpowder in a sealed pipe with detonator(as Arek suggests.) Not sure a standard fuse would set off the explosion, getting fire to ignite the powder.

Another proven failure: Propane tanks being shot, the gas is expelled and acts like a flame thrower, and can spin from the pressure. Someone on tv was showing the SAW, shot various items, including a propane tank.

Did myth busters try tracer ammo hitting the gas tank? I think it would still just burn not explode.

Hand grenade would blow up a car... not like in the movies though.

The last time I was in Belfast, I heard about this from an Irishman who lived in Donegal. He’d told me he wanted to join the Provos, and apparently they’d said, ‘You’ve got to prove yourself first. Go over to Belfast and blow up a bus.’

So the next time I saw him, he was coming out of the doctor’s with his mouth all bandaged.

‘What happened?’ I asked.

‘Sure, and I tried to blow up a bus, that I did. Only I burnt me lips on the exhaust pipe.’

Hate to necropost as my first action on this forum but due to my misspent youth I've got a few things to add. Thermite as previously mentioned is iron oxide and aluminum but it's an incendiary not an explosive. Granted the poster never said it was an explosive. If you put it on the side of the gas tank it would probably just breach the tank and set the car on fire. No boom. ANFO(google it) is a readily available and easily produced high explosive used to this date in blasting and improvised explosives. It takes no knowledge of chemistry to produce. It needs a high explosive blasting cap to detonate so it's safe too. The Ammonium Nitrate needed to make it can be obtained easily through meth heads as they use it to manufacture their drug of choice. Yay explosives.

If you want a car to burn rapidly then take a long piece of material t make a wick out of, a piece torn from a sheet is good. Place one end of the wick inside the petrol tank and run the other half into the car. Make sure the wick is soaked in petrol. Throw some petrol inside the car, set fire to the wick inside the car and run! For explosions you could add a propane gas cylinder next to the petrol tank.
I have worked with repeat TWOCers (Taking Without Concent) who have a history of stealing cars for fun. I set up a music/film making workshop. I took a load of lads to scrapyards and made a film smashing up cars in a musical fashion! It was called Junkyard Jam! It was a great success for the time it ran. Offending was cut by around 95% for the guys involved for the time the project ran.
I learned alot from the lads and from the police while doing this job. I was taught how to hotwire a car & how to disable stearing locks etc by the police. I was told that cars can take along time to burn. The lads prefered the wick method as it was the quickest way they had worked out to get the whole car engulfed in flames as quickly as possible. This was to destroy any evidence before the fire service turned up.

Pipe bombs and dynamite both are relatively slow burning explosives (although the boom looks fast). Hand grenades do not flame like shown on TV, but rather are designed to scatter metal fragments. These items can ignite a gas tank, but not likely.

No. It's a half-full gas tank with a military grade explosive on the tank (C4, Petin or Semtex). If you want to go low-tech, wrap the explosives with det-cord and use a cigarette as a delay timer. All other explosives are a crap shoot.
Oh, there's always Bangalore torpedoes and cratering charges, but they're hard to hide under a car.