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I need help to blow stuff up!

Posted: Sat, 15th Feb 2003, 12:04am

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sidewinder

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Hi.

I need to know of a way to cause something to explode, and strong enough to launch debris out of a bucket.

A film canister filled with gun powder? A pop bottle filled with baking soda and vinegar? bleach and tin foil?
Posted: Sat, 15th Feb 2003, 12:06am

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er-no

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Potassium smile
Posted: Sat, 15th Feb 2003, 12:20am

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Hajiku_Flip

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Rating: +1

Right now I'm testing that for dirt explosions. Right now I'm using these firework mortar rounds. They are designed to be shot out of this tube, but we are putting it in the ground. Here, let me draw a little diagram.

[7 minutes later]




See we dig a hole about 2 feet down, and put tons of dirt on top. Keep it a little loose so it'll blow out easy. Keep the fuse through a plastic tube so it will go into the ground, then light and run. So far the tests have been succesfull, and the ground is still frozen. Can't wait to see it in the summertime come time to shoot.

My brother is stationed in South Korea right now, and he'll be back in 25 days. He's bringing home some C4 and det wire for us to use. Det wire wrapped around twice will knock down a tree 3 feet thick. I'll look into him getting some more and I can send it to you.
Posted: Sat, 15th Feb 2003, 1:56am

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BackOfTheHearse

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C4 eek

Whoa.. A little much for amatuer films, you think?

If you ever want simple effects like smoke, sparks, fire, and small live explosions, check out Theatre FX. The things available on the site are for theatrical productions, but they can be used for film as well. It also tells you the safe working distance of all the effects and such. Pay particular attention to the bare-wire effects, which can be set off by a simple battery charge. The prices are fairly decent, too.

Or you could do what I do (which means don't do it confused ). I made my own flashpot out of a tuna fish can, and I use black powder as my explosive. I then just use a model rocket ignition system to set it off. Fairly soon, when I get a couple of dollars, I am buying a glo-plug and a remote ignition system which enables wireless ignition up to 100 feet away. biggrin
Posted: Sat, 15th Feb 2003, 2:00am

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Hajiku_Flip

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Ooops, I should of clarified myself. It's not a full block of C4, they are mini's made out of C4 materials. It's only about 3x3in square, but it still creates quite an impressive explosion.

Last edited Sat, 15th Feb 2003, 3:40am; edited 1 times in total.

Posted: Sat, 15th Feb 2003, 3:17am

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moebius

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I was about to suggest C4 as a joke - little did I know that it was readily available to home consumers wink Please please please take care when using these explosives, dudes - it's not worth losing your limbs over cool footage! biggrin
Posted: Sat, 15th Feb 2003, 3:53am

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BackOfTheHearse

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See, that's the thing about me...

Aside from things like fire and such, I am willing to get pretty well beat up. I have thrown myself down stairs, been punched, have had my head slammed into walls, fallen from rooftops and trees, and many other things that have left me pretty well hurt. But after all the yelling and swearing, my next question is always, "How did the shot look?" And if it didn't come out right, there is usually nothing to stop me from doing it all over again.

My biggest problem is my friends. The actors in my films are often so damn prissy and fussy that it drives me nuts. "Eww, I don't want blood on me. This makeup is too hot. My contact lenses burn. When is lunch? Am I getting paid for this? I am NOT throwing myself down those stairs." Admittedly, there are a lot of things that I am willing to do that no one else would, because I like the danger and I like the shots to look good. But my friends are so damn particular, it drives me nuts.
Posted: Sat, 15th Feb 2003, 5:47am

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sidewinder

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thanks for the info guys!

We have a huge supply of simple black cat firecrackers, and have taken some of them apart to get a small supply of gunpowder. Using something like a film canister, how could we get a nice bang? We did a few tests, and mostly got jets of flame or smoke.

Oh, and we are being careful.

Also, is there a way to get a large pressure release using bottles, like an explosion, which might be enough to launch debris? Such as causing a chemical reaction that makes the bottle explode?
Posted: Sat, 15th Feb 2003, 7:06am

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Ice_Man

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I got the perfect thing for ya sidey!
Pyrodex. . . also known as black powder in some circles. you can pick up a 1 pound bottle at your local Meijers for about 12 bucks after tax (estimate, I don't know what kind of sales tax y'all have in minnesota)
the most common use for Pyrodex is in muzzle loading rifles, it's not an illegal or controlled substance, anyone who looks remotely sane, and capable can purchase it with few to no questions asked. if questions are asked, then you simply need tell them that it's for special effects in a film. with the elevated level of homeland security that's in effect right now (go level orange!), you might have to be a little bit more tactful in how you approach this (i.e. send sidewinder for the pyrodex, not mecha lol )

what you'll need:
- containers, such as 20 oz pop bottles, or 12 oz cans, you can even use ping pong balls for smaller ones. since you're looking to direct debris from the explosion, you'll also want some huge coffee ground cans
- pyrodex, or black powder
- paper towel, or other sufficient flammable wadding
- lots of electrical tape
- model rocket igniters, or you can use bits of steel wool, I've found that the igniters are a bit more reliable, however. . .
- roughly 30 to 50 feet of electrical cord and a power source. now, you have a couple options here: power outlet, if one is handy, which means you need to strip the rubber coating off of one end of your wires, and make sure you have an electrical plug on the other end. your other option is to use a car battery, generally speaking this is for outdoor scenes where outlets are not available

set up:
for a simple explosion, with say, a pop can, you fill it half full with pyrodex, then connect an igniter to the bare + and - ends of the wire, put it down in there, then pack paper towel in to ensure that the igniter has contact with the pyrodex (the paper towel also adds flaming debris in the blast smile ). use the electrical tape to totally wrap the can, this is important, because if it's not sealed just short of air-tight, you won't have a big blast, you'll have a fizzle. plug the other end of the wire into the socket to set off the bomb, or connect the ends to the + and - terminals on your car battery. boom, that's all she freakin' wrote.
you're going to want at least 20 feet clearance for a bomb of this size

for a directional blast to spew debris, you follow above method (with perhaps a little more pyrodex), and set that inside the big coffee grounds can put your debris over top. set her off, and you have smoke, flames, and pieces of debris flying straight into the air!


now, a very important note, this will not make a very flame intensive explosion, like you'd expect from something like gasoline. . . what you'll get with this, is lots of smoke, a bright flash, and a loud bang, but this is actually quite a concussive little bomb. . . be careful with these, as you can get into some serious trouble with the law if you're not careful. . . trust me, I know from experience!

another thing to remember is that you're going to need to play around with this, till you get an exact method that works best for you.
Posted: Sat, 15th Feb 2003, 10:26am

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Mellifluous

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Ok, u guys, just about to follow ur tips

Testing, testing.

Just light the fuse...

*skulking behind something*

It's burning!

Oh no!

*KABBBBBBBBBBBBBBBBBBBBBBOOOOOOOOOOOOOOOOOOOOOOOM!!!!!!!!!!!!!!!!!!!!!!!!!! BOOOOOOOOOOOOOM!*


Aaaaaaaaaaaaaaaaaaaaaaargggggggggggggggggggggggghhhhhhhhhh!

My arms, my legs.........................................aaaaaaaaaaaaaaaaarrrrrrrggggghhhhhhhhh!

VERDICT: Great tips, especially Hajiku Flip's (produced best results)

Mmmm, I'll just try that again, it was fun

*KAAAAAAAAAAABBBBBBBBBBOOOOOOOOOOOOOMMMMMMMMM!!!!!!*

(Mellifluous is obliterated off the face of the planet)
Posted: Sat, 15th Feb 2003, 11:47am

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fallen

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i guess the best way to explain how to make a noisy explosion without too much damage is to think about what is happening. for example when you fill a bag with air then burst it rapidly by hitting it, you get a nice loud bang. gunpowder works much the same way (along with other explosives) by letting off a huge amount of gas in a short period of time. this is why if you just lay it on the floor and set light to it it just goes "WOOOMPH" and you lose your eyebrows. HOWEVER if its contained within something pretty airtight such as a firework, the expanding gas needs to escape quickly, and does it by destroying its container, with the effect of making a huge bang. Just like bursting an inflated bag. I'd suggest using really small airtight containers, which will only take a small amount of gunpowder. This way there is only a small amount of room for the escaping gas which will give a nice loud bang, but the explosion itself is fairly small, and will minimise limb lossage smile
Posted: Sat, 15th Feb 2003, 1:55pm

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Mellifluous

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Fallen said: "This way there is only a small amount of room for the escaping gas which will give a nice loud bang, but the explosion itself is fairly small, and *will minimise limb lossage*"

Darn!!!

U could have told me that b4

*types painfully using my nose*
Posted: Sat, 15th Feb 2003, 3:29pm

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sidewinder

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Thanks for the help, Ice_Man, and everyone else who contributed!

Quick question-Is there a way to ignite stuff without using rocket igniters? using those can become expensive if you want to do tests and stuff.

Thanks again, and once again, we are being careful about this stuff.
Posted: Sat, 15th Feb 2003, 3:37pm

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Ice_Man

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like I said, steel wool will work

if you buya big 'ole bag of steel wool, which will run you no more than 5 bucks, you can tear off tiny strips of steel wool. twist the bits until they're farely compact, and connect it to the ends of your wires just like you would for the igniters. when you connect the wire to power then, it shorts across the steel wool, causing sparks.

if you can afford it, I recommend the model rocket igniters, because the steel wool is a bit less reliable. it may take a couple of seconds before it'll blow, whereas the igniters are almost instantatneous.

but in the long run, the steel wool wil work too, and the bag should last you for quite a while
Posted: Sat, 15th Feb 2003, 4:43pm

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BackOfTheHearse

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I just remembered one of my favorite things...

Look and ask around different places, especially if you live near a community theatre. Or, go to a gas company (not a gas station) and ask. What are you asking for? DRY ICE. Frozen CO2.

If you can get a hold of some, you take it and put some in an empty water or soda bottle. You'll have to break it into small pieces to fit it in, but it will still work. I'd say to fill about 1/4 to 1/3 of the bottle with the dry ice. When you are ready to film, get your camera's rolling ahead of time. Then, pour water into the bottle. This will start the ice melting and create CO2 gas. Pretty cool-looking as it is. But, go over to what you want to blow up (your model, bucket of debris, whatever) and place the bottle in it. Then quickly place the cap tightly on the bottle and GET OUT OF THE WAY. The CO2 gas pressure will build, and eventually the bottle will burst. A bit of warning, this is LOUD. It matches and sometimes goes above the bang of an M100, so do not do it in populated areas. The explosion is pretty damn powerful, and is definitely enough to send your debris flying.
Posted: Sat, 15th Feb 2003, 4:50pm

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CurtinParloe

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In Future scenes in Terminator they used walnut dust for a flaming explosion... evil

Paul
Posted: Sat, 15th Feb 2003, 8:26pm

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MechaForce

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Hey - about the dry ice in the soda bottle -

Is there any other places where you can get dry ice? I dont get what you mean by going to a gas company - - we have gas companies around here . . but I wouldn't just walk into their factories and whatnot and say "Can I have some dry ice?"



....examples?
Posted: Sat, 15th Feb 2003, 11:13pm

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Two Gunned Saint

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Like they say blowing yourself up just for a good shot is a bad idea. However blowing other people up works even better. Before doing some of these pyro tests I advise you to ring up some old friends that you stopped talking to and never liked anyway.
Posted: Sat, 15th Feb 2003, 11:36pm

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MechaForce

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-1000 for stupid.
Posted: Sun, 16th Feb 2003, 1:09am

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supersmasher

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Well here in my HT we have a store called Central Market (it is like a gourmet supermarket for health conscious neo-hippies or some crap) and you can by dry ice from them for real cheap. I do know for a fact that Baskin Robins uses dry ice to pack their ice cream cakes. As Nitro said dry ice bombs are freakin awesome and they work well....a little too well if you as me but I'll try to find other places that sell dry ice.


Super unsure

PS: Awesome Tutorial Iceman wink and Two_gunned i bet you like to have relations with oopa-loomas or some crap huh? all freaky and crap.

Joke...but a lot of truth is said in jest... confused
Posted: Sun, 16th Feb 2003, 5:15am

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BackOfTheHearse

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As I said, ask a local theatre. Or contact one. Also, go to gas companies and say, "We are putting on a show and we want some dry ice for some good fog." If they don't have any, maybe they can point you in the right direction.
Posted: Sun, 16th Feb 2003, 5:19am

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sidewinder

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What are some other ways to get pop bottles to explode?

Just want to cover all of the bases. wink
Posted: Sun, 16th Feb 2003, 5:27am

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Ice_Man

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do you have access to scuba tanks?
if you do, I have an excellent method of debris scattering! biggrin

and before you ask, there is no explosion with this method, it will, however, blow pieces and bits of whatever all over the place!
Posted: Sun, 16th Feb 2003, 5:53am

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sidewinder

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We should shoot propane tanks while we're at it. razz
Posted: Sun, 16th Feb 2003, 6:07am

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Ice_Man

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no, because that could kill you

I wasn't talking about blowing up the scuba tanks, I said that. if you can know someone who will lend you a full scuba tank, then I'll post my method. if you can't borrow or rent one (or don't want to) then I won't waste my time