Affordable & real pyro explosion effect!!
 

Of course you had to do it again. Like you even had to tell us that. :-)

virtually all dust is explosive. Its a matter of the ratio of combustable to oxygen. Wood, Flour, Iron filings, if the ratio of combustable to oxygen is correct, and a heat source is introduced... BOOM! (Thanks to Mr. Lyle, my long ago physcis teacher... and a pyromaniac at heart)

Ah Richard, you beat me to it. Well stated! If you just think about it, take one particle of a combustible material, it's going to burn up rapidly because of the size. Place several hundred thousand of those particles next to each other in a cloud, and you have a rapid chain reaction as one particle burns and ignites the others near it, etc.

Perhaps this coming 4th of July there will be a new line of 'Emory Fireworks' on the market. ;-)


That's classic, thanks for the laugh. Yes, 'boys will be boys' huh?

-gb-

You guys know what the most commonly used "last words" are?






Hey y'all! Watch this!

Well, to be fair, that 'ratio' is a tricky thing. Each combustible has a different flash point, and the size of the particle, it's distance from other particles, etc. all play a factor. But yeah, any combustible 'dust' is potentially explosive.

That's why grain silos explode.

Try pouring powdered non-dairy coffee creamer over a lighter!

We used to ignite the powdered creamer that came in the MRE's when I was in basic-a loooong time ago.

Your tax dollars hard at work :-o

Why is it that if you get a group of guys standing around long enough, someone is going to start setting things on fire?

Actually, I think that's why cavemen worked so hard to learn the secrets of fire. When it's not whooly mammoth season what else are going to do...except light stuff on fire.

Hey, did I just figure out what brought about the end of the ice age????

Mental image forming of a caveman grunting...Uh oh, shouldn't have lit that....run!!

-gb-

So what
 

The trick is not to get things to explode. The real trick is to get the explosion to happen on cue, be the right size and be safe.

My dad was a fireman when I was a kid. I remember him telling me about a woman who was emptying the dust from her vacuum cleaner over an open trash fire (lots of people burned their trash in the back yard back in the 50s). The resulting explosion nocked her on her backside, singed her eyebrows and scared everybody.

Be careful out there.

Rob:-]

About those explosions being on cue...

I use the good old fashion acetylene "bomb" in my films. It is extremely volatile, extremely loud and makes a small intense flame, which can be used as a fuse for things such as sawdust - that and the concussion will push it even farther.

The acetylene bomb can be set off with a bb gun - a silent and ideal trigger for those needing an "on cue" explosion.

Lol... just be careful though - I've had these things go violently wrong as well, but nobody got hurt. We just all lost our hearing for a few days. Ah, to be 17 again.

¿ Care to explain the acetylene "pyrotecnics" ?

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?

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.

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.

Alec, you are a man after my own heart.

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.

LOL sweet!

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

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...





;)

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.

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.

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

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

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 ;-)

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.

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 :)

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

Home-made solid rocket fuel!

HOOOOOOOWHAAAAHH!

I don't think that mix would work as a propellent as it just detonates.

My earlier statement: 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.

http://www.dvinfo.net/conf/showpost....0&postcount=24

!= Which is what Karl referenced.

OMG ROTL
o man, and I thought I was the only one that like making my own mushroom clouds and videoing them...lol

I almost became a licenced pyrotechnician, but found quicker money in videoing weddings...lol

From Wikipedia -

Solid fuels (and really, all rocket fuels) consist of an oxidizer (substance providing oxygen) and a fuel. In the case of gunpowder, the fuel is charcoal, the catalyst is sulfur and the oxidizer is the potassium nitrate. More contemporary recipies employ such compounds as sodium or potassium chlorate and powdered aluminum. (This mixture is sometimes known as "white powder"; not only is it different in appearance than black powder, it has a considerably higher energy density.)

Maybe mixture proportions and shape-of-container determine whether you get a fast detonation or a slow burn...