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-   -   Affordable & real pyro explosion effect!! (https://www.dvinfo.net/forum/techniques-independent-production/52664-affordable-real-pyro-explosion-effect.html)

Stephen Finton October 18th, 2005 01:52 PM

I always wondered if I could fill a balloon with some volatile lighter than air gas and then light a fuse going up into the tied balloon, then let it go...

It'd make a nice round explosion. Would look good on film, too! Pseudo-Death Star explosion, anyone?

Shaughan Flynn October 19th, 2005 08:47 AM

7 parts aluminum powder to 3 parts potassium perchlorate. This stuff needs no containment. It will detonate uncontained, but I have used cardboard tubes as a vessel, sealed them with an electric match and set them off electrically. It is extremely stable.

Lots of boom. A tube about 4 inches long and 2X the diameter of my thumb placed inside an old top loading VCR, vaporized the thing. Take a plastic butter tub (like the ones that Blue Bonnet or what have you come in) and fill it half way up with Coleman gas (white gas) for the obligatory cinematic fireball.

This goes off on cue as it is electrically triggered. We built a makeshift camera sheild out of plywood and a clear polycarbonate plate that the camera looked through.

I will try to dig up one of our test videos that we did this with.

Alec Lence October 19th, 2005 10:13 AM

Just make a nice intense blue flame with an acetylene torch, this will provide the proper mixture of acetylene and oxygen. Then snuff the flame and fill a balloon with the gases and tie it off.

When we were younger we tied toilet paper to these things and lit them on fire - the waiting was very intense as these babys are LOUD. Our first experiment set car alarms off over 1/2 mile away. Our later expirement that went extremely wrong turned off all the streetlights in my neighborhood and the shockwave rattled houses over three miles away.

I can link to pictures if anybody is interested.

Shaughan Flynn October 19th, 2005 10:22 AM

Alec, you are a man after my own heart.

Alec Lence October 19th, 2005 10:49 AM

LOL, I'll take that as a yes --


This was two party balloons, toilet paper fuse
http://community.webshots.com/photo/...56146386TruQrr

Seven party balloons, taken from 1/2 mile away
http://community.webshots.com/photo/...56146422Xrwlon
make sure to view full

I don't have pictures of what my garage looked like after a balloon exploded while we were filling it as we were all standing in the street, blind, deaf and screaming. So like I said, be careful.

Shaughan Flynn October 19th, 2005 11:08 AM

LOL sweet!

What did you take those pics with tho? A cell phone?

Jim Montgomery October 19th, 2005 12:31 PM

Next thing you know you guys will be farting in a bag and touching that off......

Stephen Finton October 19th, 2005 01:36 PM

Quote:

Originally Posted by Jim Montgomery
Next thing you know you guys will be farting in a bag and touching that off......


Did you know that the elderly produce elevated amounts of static electricity due to reductions in skin oil? This coupled with increased amounts of gas due to weaker consitutions has been pinpointed as the cause behind spontaneous human combustion.

I will post pics of my grandfather on that fateful Christmas morning of 1993...





;)

James Emory October 19th, 2005 01:51 PM

Quote:

Originally Posted by Jim Montgomery
Next thing you know you guys will be farting in a bag and touching that off......

Hahahaha LMAO!!

You can produce pure hydrogen by placing tin foil in a bottle filled with drain cleaner (caution: reaction gets very warm!). Then place a balloon over the neck and allow it to fill with the hydrogen. When at capacity, pinch it off, remove from the bottle, tie it off with a string (the fuse) and light the string and it will go off way up in the air as hydrogen is lighter than air and did I mention, very flammable. When the fuse burns up to the balloon, there should be a nice flash in the sky.


Quote:

Originally Posted by Shaughan Flynn
7 parts aluminum powder to 3 parts potassium perchlorate.

Potassium Chlorate mixed with table sugar produces an intense flash when the mixture is lit but apparently neither will ingnite seperately. If it is placed in a plastic straw, a continuous whitehot flame will shoot out like a blow torch or the shuttle's solid rocket boosters.

Sodium metal will violently snap, crackle and pop emitting colorful flying sparks as it rapidly decomposes when placed in a dish of water. It will decompose slowly or melt when left exposed to air.

Shaughan Flynn October 20th, 2005 07:02 AM

Here is an example of the Perchlorate solution with white gas. That's a VCR by the way.

http://www.netnance.com/boom.avi

James Emory October 20th, 2005 08:04 PM

The explosion sound was similar to those in Looney Toons cartoons. At first, I couldn't open the video. I then right clicked, hit properties and saw a button that said something like unlock. It played after that. I've never seen that option before.

Alec Lence October 21st, 2005 12:26 AM

The acetylene bomb "boom" is similar in quality to a 10-gauge shotgun blast at point blank with a resonance similar to the most horrific thunder rumble imaginable, depending on the size of the bomb.

btw, that was a circa-2001 Sony Handycam, bitmap extracted from Premiere, not a cellphone ;-)

Dylan Couper October 21st, 2005 05:27 PM

You know, somewhere in Hell, Darwin is saying "go ahead, light that fuse, prove me right... wuss."

Anyway, I'm scratching my head here trying to figure out what kind of disclaimer to add to this thread.

So far my favorite is:
PLEASE FEEL FREE TO TRY THIS AT HOME. WE WON'T MISS YOU.

Shaughan Flynn October 22nd, 2005 09:31 AM

Quote:

PLEASE FEEL FREE TO TRY THIS AT HOME. WE WON'T MISS YOU.
ROFL!

That was shot on Hi-8 in the late 90s. A buddy of mine is a gaffer that sets up those kinds of effects and he was the one that built the explosives. We were situated about 1/8th of a mile away using his standard explosive trigger box driven off of a car battery.

As soon as we had blown one off we had to look at the tape because from our vantage we could not see much. The location is the Mojave desert about 90 minutes north east of the city of Mojave. Pretty much desolation and no one for miles.

We also had some fun with Primacord, but that is a subject for another day :)

Joe Carney October 26th, 2005 10:07 AM

I have a sudden urge to build a beercan bazooka, wonder why.
hehehe


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