flamethrower (thing)

As the previous post so eloquently puts it, flame throwers can be nasty little buggers, and might not be very useful as weapons.

However, in the field of pyrotechnics, we don't like weapons anyway, so that's okay.

Instead of talking about nasty weapons of destruction, (and instead of doing semi-lame things like making a "flame thrower" out of a lighter) I have found flame throwers to be great fun for use on stage. Therefore:

How to make your very own flame thrower

this is something I "invented" myself, and as such, it is probably possible to improve the design quite a lot. But it is cheap, and works perfectly.

The basic idea

The first thing I did in pyrotechnics was to start learning how to breathe fire. This was great, but having the liquid in your mouth while being maimed with a angle grinder or while juggling with torches can be rather nasty. Instead, I wanted to make something that did the fire breathing for me, as a small effect.

Grab one of those plant-watering bottles that disperse the water a lot, you know, into a mist of tiny, tiny droplets. Fill it with kerosene* , and blow the mist at the candle. Whee! Huge flame from small droplets.

*) NEVER USE ANYTHING OTHER THAN kerosene. Read the rest of this writeup to find out why.

The extended idea

Of course, the solution from the basic idea works perfectly, but you cannot sustain the flame for very long (unless you pump very fast, and that just looks silly) so I wanted to come up with something that made a sustained, large flame based on the same principle. I wanted something that can safely be used on stage and that looked cool.

My next raid of the local hardware store came up with some interesting ideas - I found the sort of water misters as mentioned above, but in a pump-version. The one I found dispersed the water perfectly, and was able to hold the stream going for several seconds. Great - but not great enough. It turned out that the heat made the nozzle melt, and eventually the whole thing stopped working. Damn.

The Final Idea - The Flamethrower! Whee!

Go to your local gas station, and buy a gallon of kerosene (see the "fuel" note below)

Go to your local garden centre, and ask for a weed-killer disperser. What you get then is a 3-4 gallon tank with a handle on top. That handle moves up and down to increase the pressure inside the tank (see where I'm getting at yet :). Ask if you can test it with some water. If they say no, go somewhere else.

When you try the disperser, make sure that it makes a fine mist of the water. Big drops aren't dangerous (they won't ignite), but it is not very nice to spray your audience in fossil fuels. When you are sure you have the right kind of disperser, have a look at the nozzle. Is it plastic? Keep looking. Is it metal? Then you have found your flame thrower.

Fill your flame thrower with kerosene. Go outside and put a candle somewhere with nothing flammable in a 100 foot range. Now - check the wind direction!!!. Make sure you have the wind in your back. Now light your candle, and spray your mist at the candle. Fun, isn't it? Aim it around a little, and then stop. Check your nozzle. Is it still okay? no burn or melting marks? Splendid.

Now for the tricky part - even though you now have a working flame thrower, you might want to make some kind of ignition system in front of the nozzle, so you don't need your candle. There are several ways to do this, but myself, I used an electronic fuse. Yes, they can only be used once, but it doesn't matter, really, you are unlikely to have to start and stop your flame thrower during the show anyway. And if you are, you might be better off using the candle solution anyway.

What I did when I used the electric fuse, was that I taped a 9V battery and a switch to the handle of the disperser. From there, I pulled electrical wires to about 6 inches in front of the nozzle (it won't ignite right in front of the nozzle.. You need the mist, not the flow). It looks VERY impressive during a show, to show up with a self-lighting flame thrower.

/me misses circus inferno
(the juggling / pyro / extreme performance art group I was a member of)

Words of warning

Fuel

Never. Ever. Use. Petrol. - Finely dispersed petrol (gasoline, gas, benzine, whatever you call the shit) will explode. You don't want that. Also, if you DID use it, it would continue burning after it has landed - I guarantee it will set stuff on fire. You don't want that.

Only use first-grade kerosene (or paraffin, if you are a Brit) - Don't use the stuff made for closed-circuit stoves etc. Only use kerosene made for lamps. It won't burn after it has landed (as a matter of fact, you can dip torches in kerosene to extinguish the torches. It's not recommenced, but you can.)

Wind Direction

When breathing fire, the first thing you are told to watch out for the wind. This is very important. When fire breathing, you handle about a mouthful of kerosene at the time.

When using the flame thrower described here, you put out a mouthful a second. Make sure the wind doesn't blow the burning kerosene anywhere. (With anywhere, I mean anywhere important. Have a look at the "order of importance".