Monday, June 26, 2017

Butane Wrist Mounted Flamethrower

I'll just start by saying that anyone who is frightened by the idea of myself strapping a container of pressurized flammable gas to my wrist and spewing two foot long flames from my hand should turn back now. Before I proceed any further.

Mom, I'm talking to you.

Ok, now that they are gone, I can get right down to business. 

I made a wrist mounted flamethrower.

If you are now wondering why I would make a wrist mounted flamethrower, it is now your turn to leave my website, before I proceed any further.


And for the rest of us, who are impatiently waiting for me to weed out the weirdos and get on to how to how I made this awesome piece of aerosol artillery, I can now move forward.

This is about the simplest way to make a flamethrower there is. Well, scratch that, there are several easier ways to spew flames that I have tried, such as taking a lighter to a can of hairspray, but none, however, that attach to your wrist. This is definitely the easiest and cheapest way to make one of those. I seem to have a thing for easy and cheap projects. Probably because i'm broke, and also,  in the words of Sherlock Holmes, am, "the most incurably lazy fellow that ever stood in shoe leather."

Yeah, I read too much. 


I did not make a tutorial for you. No step by step instructions telling you exactly what parts to buy and where to put them; but it is so simple that you ought to be able to figure it out without much difficulty. 

But, on to the actual thing. 

The flamethrower is powered by a small canister of butane, which I managed to attach to my arm using a combination of Velcro straps, the case to an old broken monocular, and an old too small archery arm guard. The butane is the smallest size available, the 42g can, which you can buy here
Obviously, you can use a larger can, but the flamethrower won't be as compact.

I then raided the junk drawer for random metal bits, and bought some of the smallest diameter latex tubing I could find. I found a small plastic piece (what it was I have no idea) and used it to connect the tubing to the butane canister. 

"small plastic piece"

I took a little strip of metal, drilled a few holes in it, and mounted that between the tubing and top of the canister; so that when pressed on it would release the gas. I ended up having to reinforce it with some wire, which as you can see I taped to it. It was too thin and was bending when I applied pressure to it otherwise. Then I (with no little difficulty) managed to get some string attached which went down to a loop around my finger; so that when I stretch my hand it pulls on the metal piece which releases the butane. 

After that I bought a (cheap) black glove, cut a hole in the glove, and ran the latex tubing through the hole, attaching it to a bunch of random metal nuts and washers that I glued together, which act as a heat shield. (it also looks cool)

And with that it is finished. Beautifully simple isn't it? I love that the concept can be easily modified to fit whatever materials are on hand. 

This flamethrower can spew fire over two feet, which is quite a lot when coming from your hand.

A few things to know if you make your own:
Aerosol Can
Butane is a gas. Like most gases on this blue marble of ours, it also has a liquid state. The butane is stored in the container under pressure in its liquid form. As the gas is let out, the pressure in the container drops, and so does the temperature. As the pressure drops, the liquid butane begins turning to gas, until it has expanded enough that the pressure is restored. That is how these type of pressurized aerosol products work. It is the same for hairspray, CO2, cooking spray, spray paint, propane, etc. Now, these butane canisters are designed to be turned upside down and, with the nozzle inserted into a lighter's fuel tank, transfer some of the liquid butane into the lighter; where it works with the same principle described above. With making this flamethrower, we are hacking what it's designed to do to fit our own purposes. Because of the way its designed, often some of the liquid butane will make its way into the tubing, and, because of its low temperature, freeze the tubing, which in turn will freeze your arm. (uncomfortable) The liquid butane in the tubing will also continue turning into gas, which can keep the flamethrower going even after you have stopped pulling on the string. For this reason it is best not to keep up a continuous flame for more than a few seconds. Stop and let everything warm up again. Check periodically that everything is still connected securely. You don't want the tubing coming loose from anything, or you may get a fireball within rather uncomfortable parameters to your person. Be sure there are no leaks where the tubing connects to the butane can, or on the opposite side by your glove. Since I used a rubber/plastic material glove, I have to make sure it doesn't get too hot, or let the flame touch it for too long. Not a very good idea on my part, I should have used leather or another more fire retardant material.

I reckon I should also mention that Butane is dangerous to breath in. On the can it says, "excessive inhalation can be fatal".  So......yeah. Don't inhale it.

Be Warned: This is not safe. It is dangerous to shoot fire from your hand. (duh!!) There is always the chance for something to go wrong, and with flamethrowers, if something goes wrong you are generally going to get burned. So be careful!!!

Some people might be wondering what keeps the flame from traveling back into the tubing and blowing up the butane canister, effectually turning the whole apparatus into a grenade. Those people don't understand what fire is or how fire works. The chemical reaction known as fire needs three things to sustain itself: fuel, oxygen, and heat. If it lacks any of those three things, the fire goes out. In this case, butane is the fuel, the oxygen is in the air, and the heat is added when I light the flamethrower. Here's the thing; butane is not flammable. Butane by itself will not burn. Neither will gasoline, for that matter. It is only in the presence of oxygen that they will burn. The flame cannot travel back into the tubing because there is no oxygen in the tubing, only butane. It cannot travel back into the can for the same reason. 

This is a key principle to understand when making flamethrowers. 

Danger alert!!! 

Safety Rant Ahead:

I have received some concern recently as to the safety precautions (or the lack thereof) that I take. I might as well address that here. 

First of all, I consider myself a fairly safe guy. Despite what some of y'all might think, I do not attempt projects that put myself at high risk. Trust me, I don't want to blow myself up. I make it a point to never start on a project until I thoroughly understand it. I must know exactly how it works and why. I know how this flamethrower works. I know why it works. I know the dangers involved, I know how to use it safely, and how to not use it safely. I suggest that you also do not attempt building any of my projects until you thoroughly understand them either. It prevents errors and painful mistakes. 

Secondly, I am not going to put on safety gear when it is not necessary. I am NOT the Crazy Russian Hacker. I WILL NOT put on safety glasses and say "Safety is number one priority" to go hard boil some eggs. Why? For one, safety isn't my number one priority. If safety was my number one priority I would be laying in bed wearing a bubble wrap suit in a concrete bunker 20 feet underground using only kid scissors and never taking a bath ('cause you can drown in only 2" of water) for the rest of my life. Life is dangerous. Every time you get in car you have an enormous chance of being seriously injured or killed. Yet we do so everyday. I take safety precautions only when they are necessary. Putting on safety glasses to shoot a potato cannon is like putting on a chain mail suit to chop carrots. 

Is there slight risk involved? Yeah. Is it necessary to put on safety gear? No.

Thirdly, I do put on safety gear when it is necessary to keep me safe, or when I am dealing with the unknown. I wear welding gloves when I am blacksmithing (most smiths would laugh, but who gets burned more?) I wore welding gloves and a face shield the first time I fired my Football Mortar. I don't stand too close when I light off gasoline. I wear eye protection when I play airsoft. I wear a mask when I'm grinding metal. I could go on, but you get my point.

In this project, you will notice I am not wearing any safety gear. Why? Because it ain't necessary. There is no loud noise - I don't need ear protection. Safety glasses? What for? To protect my eyes from........flames blowing in my face? Are you kidding me? By pointing the flamethrower away from my face, my eyes are not in danger, and it is not necessary for me to wear safety glasses. 

How about a bubble wrap suit people??? I mean, come on! People think I should wear a complete safety getup for shooting my football mortar. Just in case in the realm of ridiculously minuscule distant  possibility that "something" should go wrong. In fact, I should really be wearing a full on crash helmet and suit of armor when walking across our land. Because you never know when a tree might just fall on you. 

But that ^^ sounds silly. You're right. It is silly. Just as silly as me wearing safety glasses to shoot my spud gun. 

It all depends on how people perceive danger. 

Now about my glove...... well, here you might have a point. It would be best for me to have a leather glove for this, instead of a plastic/rubber/synthetic one. With a leather glove, there would be zero chance of my hand catching fire. But I was feeling cheap and bought a synthetic glove. There is a slightly higher chance of my hand catching fire. But, I tested the glove by trying to catch it on fire before I made this. Guess what? It wouldn't catch fire. It only began melting eventually after very long contact with flame. Does that make this dangerous? 

No. The glove is made of thin material, and is right on my skin. I can feel how hot the glove is. If it gets too warm, I instantly blow out the flame. I only keep the flame on for a few seconds at a time for this reason anyway. I recommend having a leather glove, as it is better. Safer by a few points. But I am not in any danger. 


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