Water Explosions

[maj_barnes]

Does anyone know a place or have any stock footage of water explosions? If so, that'd be great if you could be so kind to lend me some.
Thank you for at least looking at this thread.

[Gyro]

Throw a really gigantic rock into the water.

[maj_barnes]

I think it would be kinda of noticably seeing a large round object going into the water before an explosion. Besides, I don't think my uncle would like to have a rock thrown into his pool.

[OutcastJiob]

This is just me, but. . .

I'd put powder--blackpowder, firework guts, whatever--into a 2-liter bottle, punch a hole in the lid and rig an electric detonater, then seal the bottle so it's water-tight, weight it down with something, and toss it into the body of water. . . and then press the big red button. That would be one impressive explosion.

It's probably safe to do in a pool, too, but you'd need to float the bottle near the top of the water to get a decent effect.

Then again, the residue from the explosives might be kinda nasty in the pool water.

[Almondo99]

Detonation Films has some stock footage using the Thunderpipe. It wasnt filmed against a green or blue screen so it might be hard to key out. You could also just key out the rock and put something to stop the rock from hitting the bottom of the pool.

[maj_barnes]

I guess I have no choice but to use the rock.

OutcastJiob, your idea was good, but the residue you mentioned would be a problem.

[Carnage7p]

you wouldn't necessarily notice the rock. just use masking and it will look fine. a rock is actually a pretty darn good idea.

[maj_barnes]

I talked to Bob Forward from Det. Films and he said they tried it but it didn't work, it just made the trough of water jump four feet into the air. But he said they'd be trying it again in a month or two.

[I3lade203]

Well, in hollywood, underwater cannons are used to generate force underneath the water, and cause it to explode.. now i'm not saying to get water cannons, but prehaps you can think of some sort of system underwater that you can use to generate differnt kinds of explosions of the kind. Maybe a bit more extreme, but depends on how badly you want the effect, and how big the production is.

[OutcastJiob]

I wonder if a super soaker pumped up with only air and blasted from just beneath the surface would work? That'd be extremely cheap. . .the only problem is firing it--snorkels, anyone? Also, the person firing the gun would almost certainly be visible unless you're expert at setting up inventive camera angles.

What about bursting a balloon just under the surface of the water? Actually, I think I just got the solution. It has all the benfits of my earlier idea about a bottle bomb and none of the disadvantages: make a CO2 bomb with a bottle and float it where you need to. No powder residue left and the same explosive force.

[maj_barnes]

I would take my CO2 compresser and use that but I've been using it, and it just looks like bullet hits not explosions; but I might try a cone or something for more water shooting out. Also, this production isn't that big, so I don't intend on spending too much.

Could you also eliborate on the whole CO2 bomb, do you just pump as much CO2 into a bottle and cap it then let the cap off?

[OutcastJiob]

I messed up the name, I meant a dry ice bomb. Basically you get small pieces of dry ice and put them into the bottle, cap it, and run as fast as you can--the dry ice melts and the CO2 produced by it pressurizes the bottle so much that it detonates.

Be extremely, EXTREMELY careful if you use this method, because the timing on dry ice bombs is anything but precise. It can take a few minutes, it can take a few seconds before the bottle detonates. Squeezing the sides of the bottle in as far as you can before capping it helps, because you can see approximately how much air is in the bottle. Also, don't cap the bottle until just before you need it to detonate, or it'll end up blowing up prematurely and quite possibly causing a good bit of injury or property damage.

If the bomb is placed in a cold pool, that should delay the detonation time, so you'll have at the very least a few extra seconds. But. . .what I'd do is this. Fill the bottle with air and weight it so that it sinks into the water, but slowly--you don't want the bottle on the bottom of the pool when it goes off because that won't make much more than a bubble at the surface. Then when you're ready to shoot, get the bottle, attach the predetermined amount of weight, and put the dry ice into it. Then, roll the camera, cap the bottle after squeezing the sides of it in, wait a few seconds for the sides to start to expand (do some tests BEFORE holding this thing near your body while it's 'live'--like I said, the time before it detonates can vary greatly), and then chuck it into the water. You'll need to do a few tests with it before filming time, of course, to see just how long it will take for the bottle to explode, and so on.

Remember that the bottle is going to be throwing little pieces of plastic shrapnel everywhere when it explodes. Don't get your actors too near it.

I'm continually mentioning the dangers of this, not to scare you off, but so that you know you should be extremely careful--it's not harmless just because the "explosive" agent is dry ice and not a true explosive.

[maj_barnes]

I think I'll pass on the dry ice bomb, it does sound dangerous, and I remember dry ice has the same qualities as liquid nitrogen. So I'll stay with the rock and stock footage (whenever it comes out).

[windog]

Hi,

Just onwdering, how do you make a dry ice bomb?

Thaks

[Almondo99]

Basically you get small pieces of dry ice and put them into the bottle, cap it, and run as fast as you can--the dry ice melts and the CO2 produced by it pressurizes the bottle so much that it detonates.

The super soaker idea is good. You could even use it for water hits.

[Jasonrocks]

Throw a rock in the pool. A quick cut to the big splash will seem like an explosion.

[Jasonrocks]

Throw a rock in the pool. A quick cut to the big splash will seem like an explosion.

[Almondo99]

It's been said....double post....
Detonation films has a water explosion, but unless you want to crop it out frame by frame you should do it physically.