Propane Poppers

Fireaway · Post by **Fireaway** » Mon Jan 19, 2009 12:32 am

Looking for some advice on building propane poppers the ones that use the 1lb propane canister that are punctured.

What type of steel pipe is used for these?

Curious as to the design of the piston that punctures the cylinder, are there any pictures of this component that anyone might be able to send me.

I'm also looking for pictures of any that have been made.

Hoping to put together a display that would use these going off leading to a bigger flame effect.

Any help would be greatly appreciated.

Cheers,
Scott

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 9:16 am

You mean... to achieve this effect?

[youtube][/youtube]

Post by **Elderberry** » Mon Jan 19, 2009 9:17 am

Sounds dangerous.

JK

klondike_bar · Post by **klondike_bar** » Mon Jan 19, 2009 9:23 am

puncturing a gaseous fuel canister sounds like risky business. one spark, one guy smoking a cigarette too close, and your going home early...

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 9:24 am

jkisha wrote:Sounds dangerous.

JK

Can be, that's why its fun.

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 9:43 am

The only pictures I have of the one I've played with.

The unit is made from black iron pipe. The puncture piston is simply a smaller diameter pipe that is angle cut and sharpened with flanges welded on for support and to seal the pipe behind it to force the propane out of the vent holes.

We use a black powder "strawberry" charge to shoot the piston into the base of the propane cylinder and a secondary incendiary charge to ignite the venting propane.

The charge going off

The result

As pyro explosions go, it is actually relatively safe. In the video, Lou was approx 6 feet away in the reverse angle and jumping away from the fireball. Also in the video, you can see the fireball only lasts seconds.

Now, in terms of F/X work, we shoot everything off a fire control box under controlled conditions and I would not consider doing this any other way because you are venting a volume of highly flammable gas.

They do not work very well in the wind and that 10 to 15 foot fireball that goes vertical in still air can lay over and be a danger to spectators.

If your firing charge is too large, you'll blow the whole assembly to pieces and have large jagged shrapnel flying around.

You would also need to check into what necessary licensing would be required. Yes, the components are all over the counter, but when you assemble them, it become an explosive pyrotechnics device. In Texas to legally operate these in public requires a close proximity Special Effects Operators License and a Flame Effects Operators License. You also need a fire control box and the knowledge of what you are doing in terms of making the charges and setting the gag up for safety considerations.

While it is a very cool effect when you need a large fireball, I'm not sure Burning Man would be a good environment for it given the fact that you need to utilize explosives in the deployment of the effect. That's a whole lot of time for a mishap to happen with storage etc and it only takes one "Ooops" to result in tragedy. There are also the potential legal issues surrounding it,

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 9:45 am

klondike_bar wrote:puncturing a gaseous fuel canister sounds like risky business. one spark, one guy smoking a cigarette too close, and your going home early...

A lit cig will not ignite propane gas.

But yes, as with any explosive pyro effect, there is a decent level of risk involved from set up to detonation.

klondike_bar · Post by **klondike_bar** » Mon Jan 19, 2009 12:21 pm

looking at your video, i guess a small propane tank will a) make only small blast and b) disperse quickly into air.

still, id suggest being very careful when playing with explosives. if your charge fails to properly puncture/detonate, you may want to be very cautious when retrieving/dismantling the device.

oneeyeddick · Post by **oneeyeddick** » Mon Jan 19, 2009 12:25 pm

That seems kinda scary, Smashy, and coming from me..........

Post by **mdmf007** » Mon Jan 19, 2009 1:50 pm

It looks like a well built unit, but man the costs of popping off the 1 lb bottles and the time it takes to reload will be excessive.

Whats wrong with making one of the poppers that uses a bulk tank, an expansion chamber and a quarter turn valve to release the gas past the ignition source. they are all over the playa, and can pop off many shots for a fraction of what it would be compared to the small bottles.

simple to build (your on your own for safety)
Parts
1. bottle of whatever size gas you want with a
2. regulator screwed onto it tovregulate gas flow. This is attached to an
3. expansion chamber (bigger the expansion chamber the bigger the ball of fire) 4 inch BLACK IRON pipe with a cap screwed, and then welded on one end is the end of the barrel. Drill and attach an inlet from the regulator out line to the expansion chamber.

3A. You now have two options for a flame effect that shoots a ball of screw on a "Bell Fitting" to reduce the size from 4 inches to 1 inch, also welded into place. You need to attach a length of 1 inch pipe (36 inches or longer for safety, this prevents you from being at the business end and operating the controls at the same time. Attach a 1/4 turn gas valve in between the expansion chamber and the "barrell" this is your trigger. or get an electric valve for gas at an RV dealer. (skip step 3B and go to ignition step 4A) Expansion chamber length determines how much flame you get. You only need 6 inches of expansion chamber

3B. For a "Bang" - with less fire you need to maintain a large volume of air and introduce gas to this chamber. Neck the expansion chamber down to 1 inch the same way as the above, attach a 1/4 turn valve - electric is better here. (these thumps hurt the ears) attach another bell to INCREASE the pipe back to 3 inches and attach 36 inches of 3 inch pipe pipe. At the base of the pipe near the expansion chamber you need to drill 1/2 inch vent holes in a series around the end. This holes will introduce the air to the mix. Length of expansion chamber should be small. this regulates the volume experiment with length to get the desired bang. It takes VERY LITTLE gas to make a bang. Go to step 4B

4A. ignition source (the constantly on type so it can burn off transient gas - a small hand held torch that screws to a 1 lb bottle with the piezo electric ignition source is best) For fire effect - attach to the end of the barrel, so it ignites gas as it comes out of the 1 inch barrell. Plumb it back to the bottle after the regulator with a "T" fitting so it is always on this is important detail.

4B. for pop effect, drill a larger 1 inch hole half way up the "barrell" affix a bracket, so the flame from the torch will blow through the hole into the inside of the barrell. This will ignite the air gas mixture as it goes through the pipe making the bang. Plumb the torch into the gas supply with a "T" instaleld after the regulator, and before the expansion chamber.

For both models, make damn sure there is nothing at the business end that you down want burned, or bleeding from the ears. Make the construction solid, and mount appropriately. Saftey stops and limits are appropriate to make sure it cant be aimed down at someone on accident.

OPERATION.

1 Close valve to barrel
2 Open regulator on bottle and ignite the torch
3 you are in business
4 open 1/4 turn valve for effect electric valves are a big advantage for distance.

I will try to come up with some drawings. You can buy the Bird Banger, AKA as a Propane Cannon premade from suppliers. They are used at airport to scare off birds and cost about 675.00.

Have fun,

all liability is yours. We have made both models for about 75 bucks each.
http://www.aquamerik.com/catalogue/prod ... aux&lg=eng

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 4:25 pm

klondike_bar wrote:looking at your video, i guess a small propane tank will a) make only small blast and b) disperse quickly into air.

still, id suggest being very careful when playing with explosives. if your charge fails to properly puncture/detonate, you may want to be very cautious when retrieving/dismantling the device.

A pounder will make a decent sized fireball. In still conditions though, it is safe for an actor/stunt guy to start moving only a few feet away as the blast will travel up with minimal outward spread.

The video had a dud fire and as long as your primary charge and incendiary charges have fired, its "safe". The propane can either vented or it didn't. Once you are out of the box (wires pulled, fire control off) and cold, even if your powder charge or incendiary charge didn't fire, you are still as safe as possible.

Like I said, my experience with doing this involves a controlled environment and a professional effects crew with medical and fire standby.

With a suitable magazine on site for materials storage and a professional crew, I would see something like this not being an issue to fire off on the Playa.

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 4:28 pm

oneeyeddick wrote:That seems kinda scary, Smashy, and coming from me..........

If I knew Steve was shooting it, I'd have no issues doing a tuck and roll for 4 feet away of it going off.

Dustdevil · Post by **Dustdevil** » Mon Jan 19, 2009 4:40 pm

While the propane popper appears simple in its' design, there are several subtle items which must be built into the system. We have used ours for years without any issues. While the components are easily obtained and can be fabricated with normal metal shop tools, the firing system is the key. First let's make certain we are speaking of the same devise. Essentially you have a wedge that is forced into the propane cannister. This causes the propane to vent rather rapidly. The same force that pushes the wedge also ignites the gasseous propane. They make wonderful toys and great Christmas gifts. The real issue is the BP charges. To create the charges you will need a source of 2FA black powder. To insure positive fuel ignition we doctor the powder with titanium sponge. 200 mesh is nice. You can use titanium grannuals as well. You will also need Ematch. Ematch is now controlled by the ATF so you will need a license or a "source" for that. When you are ready contact me off list and I can give you the mixing ratios and the charge construction info.

This is a device that will bring hours of fun to your neighborhood. While they are not really load, their low frequency noise will set off car alarms for blocks around. My neighbors have grown to expect this at irregular intervals.

Dustdevil · Post by **Dustdevil** » Mon Jan 19, 2009 4:51 pm

BTW,

The popper that the Captain has pictures of is just like the ones we build, except we put a small base on ours so it doesn't roll around. And all his information is spot on. I think he may have some experience in this field. If you wish to only make a LOT of noise, check out this item on Ebay.
150315861007

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 7:31 pm

Dustdevil wrote:BTW,

The popper that the Captain has pictures of is just like the ones we build, except we put a small base on ours so it doesn't roll around. And all his information is spot on. I think he may have some experience in this field. If you wish to only make a LOT of noise, check out this item on Ebay.
150315861007

The pictures above are the first prototype Steve built. He has since added feet to one end to keep it from rolling.

And yeah, I've been on a set or two in the past. My primary role is weapons master, but I jump in and lend a hand to effects whenever possible.

theCryptofishist · Post by **theCryptofishist** » Mon Jan 19, 2009 7:32 pm

I am torn between reminding everyone about the poor woman in 07 who was hit by shrapnel from a can in a fire barrel (yeah, I know, not the same thing) and admitting that if you're going to get this kind of advice, these are probably not bad people to get it from.

What is our responsibility, anyway? (Morally speaking, I don't want to talk about legal entanglements.) Basically we want good information going to good (in a responcible and technically competent sense, not on Santa's "nice list" sense), not good information going to people who cannot take it or bad information going to people who don't know it's junk.

I think I'm running into the Ouroboros here.

Dustdevil · Post by **Dustdevil** » Mon Jan 19, 2009 7:45 pm

The information needed to construct such a device is readily available. I offer my assistance only to help others do it right so there is no situation. If the person requestion the info is resourceful enough to obtain the BP and ematch, then I have no problem assisting with the safe use of those materials. However, I will not be the supplier of the said materials.

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 7:51 pm

It should not be the same thing as the idiot tossing a can in a fire, but a homebuilt design that is not overbuilt and heavily tested could easily wind up in the same category on a much more destructive level to people and property. A pound of propane would make a very big kaboom if it did not vent properly and shred a thin walled steel casing like paper.

As Dustdevil pointed out, its a simple, very straight forward design but there has to be some serious thought put into that design from a knowledge base of dealing with explosives and a deep respect for what dangers the individual components possess alone and when combined.

mdm has described, in my humble opinion, a much more appropriate and cost effective alternative that would be more suited to the Playa environment. Primarily because it does not need explosives or an ematch for deployment. It also lessens the risk of a catastrophic, explosive failure due to inexperience and the environment.

CapSmashy · Post by **CapSmashy** » Mon Jan 19, 2009 7:53 pm

Dustdevil wrote:The information needed to construct such a device is readily available. I offer my assistance only to help others do it right so there is no situation. If the person requestion the info is resourceful enough to obtain the BP and ematch, then I have no problem assisting with the safe use of those materials. However, I will not be the supplier of the said materials.

Same here. I'd rather help someone build it right than ignore it and read about them blowing themselves up later.

theCryptofishist · Post by **theCryptofishist** » Mon Jan 19, 2009 7:55 pm

That's sort of what I thought. I knew there was no way to keep the information hidden.

Remember when The Anarchist Cookbook was an out of print book that was one of the few sources of information on the subject.

I am so fucking old.

oneeyeddick · Post by **oneeyeddick** » Mon Jan 19, 2009 8:34 pm

Don't age yourself, Fishy, I have anarchist cookbook still from when I was a late teener.

Pretty archaic book, but a lot of dangerous info is in there, and in the wrong hands
it can lead to bad things happening if not done right.

Thus the need to point things out further if some of us are in the know of a safer way, ya know ?

Post by **AntiM** » Tue Jan 20, 2009 5:16 am

Hey, I have one of those cookbooks.

General Disorder · Post by **General Disorder** » Tue Jan 20, 2009 6:09 am

[quote="Dustdevil"]BTW,

The popper that the Captain has pictures of is just like the ones we build, except we put a small base on ours so it doesn't roll around. And all his information is spot on. I think he may have some experience in this field. If you wish to only make a LOT of noise, check out this item on Ebay.
150315861007[/quote]

ya gonna protect your camp with a few of these....scare away the wildlife and predators??

Sail Man · Post by **Sail Man** » Tue Jan 20, 2009 10:42 am

AntiM wrote:Hey, I have one of those cookbooks.

ditto

phil · Post by **phil** » Tue Jan 20, 2009 11:38 am

> What is our responsibility, anyway?

This photos shows _your_ responsibility:

It's your (and my) responsibility to participate. People are hurt at Burning Man. People die at Burning Man. People die on their way to and from Burning Man. If you're (and if I'm) not willing to participate, then don't prevent the participation of others.

It's Burning Man.

CapSmashy · Post by **CapSmashy** » Tue Jan 20, 2009 1:48 pm

phil wrote:> What is our responsibility, anyway?

This photos shows _your_ responsibility:

It's your (and my) responsibility to participate. People are hurt at Burning Man. People die at Burning Man. People die on their way to and from Burning Man. If you're (and if I'm) not willing to participate, then don't prevent the participation of others.

It's Burning Man.

Ya know, I understand that aspect of it and all, but if I see someone setting up something like a can popper that I can tell is not made well and has bomb potential, I'm gonna say something, Burning Man or not.

Maybe you can live with yourself utilizing the "Oh well, that's Burning Man" excuse and ignore a serious design flaw in a device that could kill people, but I would find it unconscionable to not say something.

phil · Post by **phil** » Tue Jan 20, 2009 2:44 pm

> I would find it unconscionable to not say something.

That' fine - that's part of Burning Man. Posting a query here and finding out how to do it right is part of the participation.

Elorrum · Post by **Elorrum** » Tue Jan 20, 2009 7:17 pm

"I think I'm running into the Ouroboros here" there's a rejoinder to that isn't there? I can't quite get a handle on it. something about how running into the ouroboros is also the same as runnning out of the ouroboros, but that's not quite it. help, fishy.

StevenGoodman · Post by **StevenGoodman** » Wed Jan 21, 2009 4:58 pm

An incorrectly made "propane flame effect device" is a lot more dangerous. By expanding the propane (in an accumulator) before mixing it with air and igniting it you get a lot more "boom" for the buck.

i.e. one pound of propane expanded, and then released and igniting will make a much bigger boom...

Martini Steve

Dustdevil · Post by **Dustdevil** » Wed Jan 21, 2009 6:08 pm

Steven is absolutely correct. The propane popper has a very low db level. BUT, the great low frequency will set off car alarms. Good Stuff. Also, a popper such as these cannot be compared to throwing a cylinder in a fire. Throwing a cylinder in a fire causes the pressure to build up until it blows off the safety (if it has one) or explodes. In a propane popper you are simply venting the gas and igniting it. A serious burn hazard if you are too close, but no explosion hazard. The explosion hazard comes from using the wrong BP or the wrong amount of BP.