Thread: Flame Throwing Pumpkin Theatrical Set Piece

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This display produces an actual instantaneous burst of flame with an audible Whoomp! It is much safer than the ill-advised remote control flame thrower pumpkins which utilize a can of compressed hair spray or other compressed flammable gas to shoot fire out of a pumpkin.

Even though this is a relatively “Safe” display, you will be creating actual flames and basic safety precautions should be observed at all times. This display also requires a hands-on operator and a bit of theatrics.

This flame throwing pumpkin display is rather edgy and should only be performed in a very well ventilated space or outdoors. It may not be suitable for younger children and is capable of scaring even the most jaded high schoolers…

Materials:

3 tubes of CaC2 (Calcium Carbide; a hygroscopic chemical salt); also popularly known as Bangsite; available on eBay and elsewhere. Each tube will provide around 30 firings.
1 large pumpkin
1 long-nose grill lighter (good to have a spare one, too)
1 small water basin
1 2-liter bottle of water
1 fire extinguisher (you won’t need it, but you will be creating real flames here, so it’s a sensible precautionary item)

Preparation:

Carve out the top of the pumpkin in the usual manner and discard; make the hole in the top a bit smaller than usual, but large enough so your hand can reach inside the pumpkin. Clean it out. Carve the face and make it a “Scary” visage. The facial features should be nice and big as flames will be shooting out of them. The mouth feature should be big enough to slide in a basin of water – a pot pie bowl is perfect for this purpose. In the back of the pumpkin, just below the center, drill a hole to accept the tip of the long grill lighter.

Operation:

Fill the water basin about half way and place it inside the pumpkin, insert the grill lighter in the hole in the back. Open the tube of Bangsite and pierce the seal (keep the tube of Bangsite sealed at all times when not in use as it absorbs moisture from the air which ruins it). The firing operation: With one hand on the grill lighter trigger, pour a half thimble (or large pinch, it takes about ½ second to do the pour) of Bangsite through the open top of the pumpkin into the water basin below. Let it fizz for about ½ second, then ignite the lighter – instant Whoomp accompanied by a momentary tongue of flame!

Notes:

There will be a faint chemical odor; this is from the acetylene gas released when the CaC2 mixes with water. After every 20 firings or so the water basin should be changed; the white residue in the water is calcium -- I dump it behind the bushes. You should keep people about three feet away when igniting the pumpkin. I’ve been doing this stunt for over ten years and have never had an incident. The flame is instantaneous and not much heat is released, but you shouldn’t invite a disaster. People may get a little touchy if you immolate their children…

Theatrics:

I perform this gag every year, either in the garage or on the front porch. The flaming pumpkin sits on a nightstand right next to my chair. Trick-or-treaters usually travel in packs; I try to get 3 or 4 together and say something like; “Stand back, I have to light the pumpkin”, then Whoomp!; and they all run away screaming … More candy for me!

Happy Halloween

I would be happy to answer any questions you may have concerning this stunt.

Sounds intriguing... got any video?

I'd probably not be able to do this one... I have a tendency to break things and fire is probably not a good thing for me to play with.

Great concept, and would love a video.

But, I need to ask.

How much is the Calcium Carbide?

From a very rudimentary price search for miner's grade, I would think it would be cheaper to purchase flash powder...(magic supplies)

pirotechnics and Halloween? what a combination.

Bangsite is available here:

BIG-BANG Cannons Conestoga Company

It costs $8.50 per tube (about the size of a tube of tooth paste). It's sometimes cheaper on eBay. Only buy a new vacuum sealed tube of Bangsite; as soon as a tube is opened it starts to slowly degrade due to moisture in the air.

Miners grade CaC2 has larger chunks; Bangsite is the consistency of fine sand and easy to dispense and reseal. You can buy a train load of CaC2 relatively cheap (it is used by industry to make acetylene gas) but smaller quantities are expensive… Back in the day it was commonly available at gas stations and used in automobile headlights.

I don't have a video, sorry, but the wife got a fancy new video camera for Christmas last year and I will film this year’s display for all to see!

Flash powder may be a good alternative! Thanks for the tip, I'll have to check that out! I’m used to working with CaC2 because I build giant sized carbide cannons (6 foot long barrels made from 5 inch diameter threaded steel pipe) and they require a lot of Bangsite to operate.

Video or it didn't happen!

This video illustrates the effect I'm creating with the exploding pumpkin:

[ame=http://www.metacafe.com/watch/659792/carbide_explosions/]Carbide Explosions!! - Video[/ame]

He is using Bangsite, the same stuff I use. Note that he doesn't give enough time between blasts for the oxygen to replenish; you need some O2 to mix with the acetylene gas for the best effect. You also want to avoid doing this in a closed container because acetylene detonates instantaneously rather than burn slow like gunpowder -- shrapnel = bad!

Nice! I like! Definately gonna use that! Thanx!