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9/22/2017 12:11:25 AM
Posted: 4/1/2006 12:49:28 AM EDT
So my friend who's a film student comes to me today and says "Enigma! I need big firey explosions for one of my field-productions project can you help me?" I said sure, and I have some ideas but any of you guys have some ideas for good movie explosions? Thanks.


Oh and I'll need a good source for movie blanks and adaptors.
Link Posted: 4/1/2006 12:55:13 AM EDT
Tannerite, duh.
Link Posted: 4/1/2006 12:58:03 AM EDT
I would have to get blasting caps to set it off. plus, oil-based explosions look much better on film. I was thinking a gas-diesel mix dispearsed by a BP charged detonated electrically with heating elements.
Link Posted: 4/1/2006 1:04:21 AM EDT
Propane tanks cut in half and filled with gasoline seem to be popular in the special effects industry. That's what they used in the movie Toy Soldiers. Make sure they know what they're getting in to, if they're going to detonate inside a shrapnel source like a car.
Link Posted: 4/1/2006 2:06:21 AM EDT
Do you know how they disperse the mixture?
Link Posted: 4/1/2006 2:57:35 AM EDT
Firecrackers and a Revell or Monogram model kit.
Link Posted: 4/1/2006 3:13:48 AM EDT
C-4
Link Posted: 4/1/2006 12:25:56 PM EDT

Originally Posted By FieroLoki:
C-4


riiiiight, would you happen to have any I could buy then?
Link Posted: 4/1/2006 12:26:58 PM EDT

Originally Posted By Enigma102083:
So my friend who's a film student comes to me today and says "Enigma! I need big firey explosions for one of my field-productions project can you help me?" I said sure, and I have some ideas but any of you guys have some ideas for good movie explosions? Thanks.


Oh and I'll need a good source for movie blanks and adaptors.



did you start giggling when he asked you?
Link Posted: 4/1/2006 12:29:25 PM EDT
uh-oh darwin is going to be watching this one
Link Posted: 4/1/2006 12:40:47 PM EDT


take plastic "drop cloth" for painting X 6 and lots of duct tape. about 20 feet cubed will do nicely fill with 3:1 oxygen : acetylene

detonate from twice as far as you think you need to be, but about half as far as you should have been. post video on the internet..... if you survive..... so everybody can make darwin jokes.

Link Posted: 4/1/2006 12:42:15 PM EDT

Originally Posted By santanatwo:

take plastic "drop cloth" for painting X 6 and lots of duct tape. about 20 feet cubed will do nicely fill with 3:1 oxygen : acetylene

detonate from twice as far as you think you need to be, but about half as far as you should have been. post video on the internet..... if you survive..... so everybody can make darwin jokes.



I know enough to know that isn't a good idea. I've done oxy acetylene explosions before. Nice try though.
Link Posted: 4/1/2006 12:47:04 PM EDT
PROPANE!
Link Posted: 4/1/2006 12:48:22 PM EDT

Originally Posted By Enigma102083:
I would have to get blasting caps to set it off. plus, oil-based explosions look much better on film. I was thinking a gas-diesel mix dispearsed by a BP charged detonated electrically with heating elements.



I set off a black powder explosion for my nephew's ash cone science project with a coiled 1-1/2" piece of tie wire, 100' of speaker wire, and an 18V DeWalt battery.
Link Posted: 4/1/2006 4:49:47 PM EDT
Ah hell, just paint it in with FinalCutPro in post, just like in hollywood. A few red gells to light your actors faces as they gape at it, and your all set.
Link Posted: 4/1/2006 4:54:07 PM EDT
[Last Edit: 4/1/2006 4:57:41 PM EDT by NimmerMehr]

Originally Posted By thelastgunslinger:
Tannerite, duh.



Won't show well on film, if at all. Edit: It will ,but it might not be cool to the film maker.


All the big fireballs the movies love are low velocity explosions, so the fire ball is not snuffed by the shockwave I assume.

High velocity is called a detonation and low velocity is a deflagration.

http://en.wikipedia.org/wiki/Detonation


Link Posted: 4/1/2006 5:01:00 PM EDT
THAT FUCKING RULES



Originally Posted By azhammer:
PROPANE!href=i41.photobucket.com/albums/e281/azhammer/marr/DSC00420.jpg
Link Posted: 4/1/2006 5:21:07 PM EDT
Road flare...

Propane tank...

55 g. steel drum of gas... (well sealed, don't want the fumes to go off with the road flare)

I've never seen it, or tried it, but I'd imagine it would be cool!
Link Posted: 4/1/2006 5:26:30 PM EDT
Propane works but there are serious hazards with it due to the pressure. If you try to release it from a valve, it looks like a flame thrower, not exactly like an explosion.

For the real movie type explosions, you need benzoyl peroxide with a fuel moderator. In large quantites, it will detonate so you add a fuel like oil to slow it down. These are expensive FX and used only for simulation of grenade-sized explosions and smaller and inside a set/building where blast overpressure is to be avoided, after all, the crew needs to survive.

Good luck on finding it in the quantities you need. Its available but the shit is some serious hazmat and needs to be kept wet until needed, then you dry it and mix.

Real explosions with high explosives are not that spectacular unless you add fuel. IIRC, bomb simulators for some special effects are gasoline in bags over a small quantity of high explosive. They are frequently assembled in cardboard boxes to guide the fuel into the desired cloud. The gasoline burns on the outside of the resultant cloud, making a fireball of considerable duration. This is ONLY DONE OUTSIDE for obivious reasons. Never even think about doing it with Tannerite inside a building.

Link Posted: 4/1/2006 5:44:30 PM EDT
The problem with capturing explosion effects in a movie is the shutter time.
At 1/1000 sec shutter and 24 frames per second the shutter is only open 0.024 seconds for each second of film.
This means the shutter is closed 97.6% of the time.
Any flash that lasts less than about 83 milliseconds is unlikely to get caught in even 1 frame, let alone persist long enough to look like what Joe Average thinks an explosion looks like (partly since Hollywood has conditioned them).
Real explosives make flashes that are just to brief to be caught by a movie camera at the normal 24 frames per second. Even gunfire is to brief with regular smokeless powder.
By adding gasoline (or other fuels) the typical movie fireball is created. It persists for multiple frames and ‘looks’ correct.

Link Posted: 4/2/2006 1:32:50 AM EDT

Originally Posted By Keith_J:
Propane works but there are serious hazards with it due to the pressure. If you try to release it from a valve, it looks like a flame thrower, not exactly like an explosion.

For the real movie type explosions, you need benzoyl peroxide with a fuel moderator. In large quantites, it will detonate so you add a fuel like oil to slow it down. These are expensive FX and used only for simulation of grenade-sized explosions and smaller and inside a set/building where blast overpressure is to be avoided, after all, the crew needs to survive.

Good luck on finding it in the quantities you need. Its available but the shit is some serious hazmat and needs to be kept wet until needed, then you dry it and mix.

Real explosions with high explosives are not that spectacular unless you add fuel. IIRC, bomb simulators for some special effects are gasoline in bags over a small quantity of high explosive. They are frequently assembled in cardboard boxes to guide the fuel into the desired cloud. The gasoline burns on the outside of the resultant cloud, making a fireball of considerable duration. This is ONLY DONE OUTSIDE] for obivious reasons. Never even think about doing it with Tannerite inside a building.



this is esentually what I'm gonna go fore. gas-diesel mix dispersed with a BP charge from inside some sort of focused chamber, probably small propain tanks cut in half with wires running in from the bottem.

Link Posted: 4/2/2006 5:32:39 AM EDT

Originally Posted By Enigma102083:

Originally Posted By Keith_J:
Propane works but there are serious hazards with it due to the pressure. If you try to release it from a valve, it looks like a flame thrower, not exactly like an explosion.

For the real movie type explosions, you need benzoyl peroxide with a fuel moderator. In large quantites, it will detonate so you add a fuel like oil to slow it down. These are expensive FX and used only for simulation of grenade-sized explosions and smaller and inside a set/building where blast overpressure is to be avoided, after all, the crew needs to survive.

Good luck on finding it in the quantities you need. Its available but the shit is some serious hazmat and needs to be kept wet until needed, then you dry it and mix.

Real explosions with high explosives are not that spectacular unless you add fuel. IIRC, bomb simulators for some special effects are gasoline in bags over a small quantity of high explosive. They are frequently assembled in cardboard boxes to guide the fuel into the desired cloud. The gasoline burns on the outside of the resultant cloud, making a fireball of considerable duration. This is ONLY DONE OUTSIDE] for obivious reasons. Never even think about doing it with Tannerite inside a building.



this is esentually what I'm gonna go fore. gas-diesel mix dispersed with a BP charge from inside some sort of focused chamber, probably small propain tanks cut in half with wires running in from the bottem.




Why does everyone go with metal containers? That is dangerous. Use plastic bags full of gasoline in round cardboard concrete form tubes (Sonotube) You might get acceptable performance with BP but I have never tried it.
BP is more of a lofting charge but if you try 4F, you might get acceptable performance.

I have been to anvil shoots where one ounce of blasting powder, a crude and coarse form of BP, is placed underneath a heavy anvil and time from explosion to the anvil hitting the ground again is a measure of the strength of the powder. There is a LOT of energy in blasting powder, keep it away from metal items.
Link Posted: 4/2/2006 10:34:41 AM EDT
be sure and show a vehicle driving off a cliff and exploding in mid air
Link Posted: 4/2/2006 1:33:46 PM EDT

Originally Posted By Keith_J:
Originally Posted By Enigma102083:
Originally Posted By Keith_J:


Why does everyone go with metal containers? That is dangerous. Use plastic bags full of gasoline in round cardboard concrete form tubes (Sonotube) You might get acceptable performance with BP but I have never tried it.
BP is more of a lofting charge but if you try 4F, you might get acceptable performance.

I have been to anvil shoots where one ounce of blasting powder, a crude and coarse form of BP, is placed underneath a heavy anvil and time from explosion to the anvil hitting the ground again is a measure of the strength of the powder. There is a LOT of energy in blasting powder, keep it away from metal items.


I was planning on putting the containers underground. I figured that having them burried would help contain any shrapnel where the explosion to not go as planned. Plus no one is going to be anywhere near these things in the shots.
Link Posted: 4/2/2006 2:00:47 PM EDT

Originally Posted By Enigma102083:

Originally Posted By Keith_J:
Originally Posted By Enigma102083:
Originally Posted By Keith_J:


Why does everyone go with metal containers? That is dangerous. Use plastic bags full of gasoline in round cardboard concrete form tubes (Sonotube) You might get acceptable performance with BP but I have never tried it.
BP is more of a lofting charge but if you try 4F, you might get acceptable performance.

I have been to anvil shoots where one ounce of blasting powder, a crude and coarse form of BP, is placed underneath a heavy anvil and time from explosion to the anvil hitting the ground again is a measure of the strength of the powder. There is a LOT of energy in blasting powder, keep it away from metal items.


I was planning on putting the containers underground. I figured that having them burried would help contain any shrapnel where the explosion to not go as planned. Plus no one is going to be anywhere near these things in the shots.



Sounds good. Be sure to overcrank. Are you shooting 35mm film? Get you hands on a Photosonics camera and shoot it around 200 or 350 fps.

Mix diesel and gasoline for color and smoke.

Years ago I was on a shoot where we used propane bomb (Harrisin Ford prison movie or maybe a Stevan Segal film, I don't remember) These were essentialy steel tube where in would fit a standard propane cylinder. These tubes were slotted in many places with a cutting torch and had another one inch tube with a cap welded to it at right angles. A blasting cap went into the one inch tube behind a wedge shaped slice of steel rod. The cap worked to shoot the wedge into the cylinder and punch a big hole in it and the propane was lit by an electric match. Rolling fireball. We did these in a bus with cannons to blow out the windows first....

efxguy
Link Posted: 4/2/2006 2:21:14 PM EDT
Before and after picks of all involved, please! The injuries will be interesting, and depending on where you do this, don't forget to leave the dog at home and have your lawyers number.
Link Posted: 4/2/2006 2:25:51 PM EDT

Originally Posted By Grumple:
THAT FUCKING RULES



Originally Posted By azhammer:
PROPANE!
i41.photobucket.com/albums/e281/azhammer/marr/DSC00420.jpg





Thank you
Link Posted: 4/2/2006 2:26:24 PM EDT

Originally Posted By efxguy:

Originally Posted By Enigma102083:

Originally Posted By Keith_J:
Originally Posted By Enigma102083:
Originally Posted By Keith_J:


Why does everyone go with metal containers? That is dangerous. Use plastic bags full of gasoline in round cardboard concrete form tubes (Sonotube) You might get acceptable performance with BP but I have never tried it.
BP is more of a lofting charge but if you try 4F, you might get acceptable performance.

I have been to anvil shoots where one ounce of blasting powder, a crude and coarse form of BP, is placed underneath a heavy anvil and time from explosion to the anvil hitting the ground again is a measure of the strength of the powder. There is a LOT of energy in blasting powder, keep it away from metal items.


I was planning on putting the containers underground. I figured that having them burried would help contain any shrapnel where the explosion to not go as planned. Plus no one is going to be anywhere near these things in the shots.



Sounds good. Be sure to overcrank. Are you shooting 35mm film? Get you hands on a Photosonics camera and shoot it around 200 or 350 fps.

Mix diesel and gasoline for color and smoke.

Years ago I was on a shoot where we used propane bomb (Harrisin Ford prison movie or maybe a Stevan Segal film, I don't remember) These were essentialy steel tube where in would fit a standard propane cylinder. These tubes were slotted in many places with a cutting torch and had another one inch tube with a cap welded to it at right angles. A blasting cap went into the one inch tube behind a wedge shaped slice of steel rod. The cap worked to shoot the wedge into the cylinder and punch a big hole in it and the propane was lit by an electric match. Rolling fireball. We did these in a bus with cannons to blow out the windows first....

efxguy



Filming will be digital I'm pretty sure but I'll pass on your sugestions.
Link Posted: 4/2/2006 2:56:06 PM EDT
Someone should be around to perform a back two-and-a-half somersault one-and-a-half twists pike at the point of explosion.
Link Posted: 4/3/2006 2:35:05 AM EDT

Originally Posted By Grumple:
THAT FUCKING RULES



Originally Posted By azhammer:
PROPANE!
i41.photobucket.com/albums/e281/azhammer/marr/DSC00420.jpg




what would rule even fucking more if this was true...so what is up grumple?? april fools or what??

ar15.com/forums/topic.html?b=3&f=16&t=276074
Link Posted: 4/3/2006 2:37:07 AM EDT

Originally Posted By smokycity:
Firecrackers and a Revell or Monogram model kit.



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