DIY Matchhead Cannon Brings The Heat

If your local surplus store is fresh out of supercapacitors but you’re just really in the mood to fire stuff at other stuff, check out [austiwawa]’s step-by-step guide to building a thermal cannon. It shoots whatever will fit into a 1/2″ copper pipe, propelled by cut-up matchheads and lit by a propane torch. [austiwawa] demonstrates it by firing an AA battery at an unsuspecting pumpkin. For what it’s worth, we don’t necessarily condone applying this much heat to alkaline cells.

[austiwawa] used a copper pipe for the barrel because it provides the fastest heat transfer. One end of it is flattened and folded over to form the propellant chamber. A couple of packs worth of match heads are tamped down into the folded end with a paper towel serving as wadding. [austiwawa] tosses in his battery, lights the torch, and then runs away.

This whole dangerous contraption is secured to a wooden base with a u-bolt and a couple of pipe straps, and suspended between more pieces of wood with a length of threaded rod for stability and aiming.

We’ll let the safety-conscious readers do our work for us in the comments, but in the meantime, note that this thing is not safe. As [austiwawa] demonstrates, the copper gets brittle and will split open along the folded edge.

But kudos anyway to [austiwawa] for showing shot after shot of the cannon in action at the end of his video. You know where to find it.

If it’s a stronger, more beautiful barrel you’re after, just machine one by hand.

20 thoughts on “DIY Matchhead Cannon Brings The Heat

    1. Also called a pipe rocket.

      (1) I’m glad I did all this before 9/11 up in Canada when I was a dumb teenager
      (2) I’m amazed that neither me nor any of my friends lost fingers in the process. Homebrew rocket fuel is a little more tricky than some blogs make it out to be.

    2. Yep. Made a pipe bomb once from cheap mayerials, match heads and an Estes rocket motor igniter. Thing blowed up real good. I’m really glad I didn’t kill myself, start a fire or hurt anyone.
      Nope, I was smart. I set my Russian Roulette Suicide Toy off in an abandoned sand pit and I dug a hole in the ground to put it in when I was ready to set it off. Not like this kid, shooting a smoothbore weapon/bomb in the backyard, launching batteries towards the neighbor’s house. With a burning propane cylinder. On mom and dad’s back porch.
      Holy shit, why hasn’t anyone sent the cops around to pay this kid a visit?

  1. this is stupid, match heads are dangerous as propellant.

    anyone who loads there own ammo will tell you that “gun” powder, nitro-cellulose and even black powder, does not “explode” it burns.

    when you work up a new load for a projectile weight that is not listed in your loading guide, you approach it VERY cautiously.
    The powder needs to burn evenly, with a minimum of “swirl”.

    match heads are the last resort of school kids looking for giggles.
    they don’t burn evenly and are just plain dangerous

    3 match heads in an enclosed container have the same force as a yellow ramset cartridge and can put a steel bolt through quite a bit of hardwood.

    1. I think when you say it does not “explode” that you mean “detonate.” Black powder burns, rather than detonates, but it’s still classified as a low explosive.

      As a reloader I’ll agree with the rest of your comment.

      1. black powder can “detonate”

        When it burns up, the granules first turn from carbon to carbon monoxide, which retains about 70% of the energy. The CO and oxygen gas from the decomposing salt-peter then burns to CO2 and releases the rest of the energy. If the chamber pressure grows too high too fast, you get the same effect as knocking in a gasoline engine, where the entire volume of fuel/oxygen mixture ignites at once – which is similiar to detonation.

        It produces a huge pressure spike which destroys the gun, which is why black-powder firearms are restricted to relatively low chamber pressures and low velocities. Black powder just isn’t stable enough to high pressure – it’ll just shatter the gun in your face.

    2. Not to mention that cut up match heads can easily go from deflagration straight to detonation (gun/cannon becomes a bomb), whereas smokeless powder is very unlikely to do this, even at large quantities.

  2. I do something like this on 4th of July, only i light it with an electric model rocket igniter and use a cardboard tube (like a model rocket body tube) so if it explodes there isnt any solid shrapnel

  3. If I was to go and do this, I’d look at drilling the chamber into a small block of copper and rounding the end of it into a hemisphere and then brazing that to something like a narrow diameter piece of black iron gas pipe for a barrel. The crimped end I would not trust, and making the whole thing out of copper would wick the heat away from the chamber very rapidly. I’d think a small block of copper with fins or other cuts into it would heat up faster due to the smaller volume, and finning it should make it cool down enough for a reload faster when the torch is removed.
    Or a piece of black iron pipe, a cap, and make an induction heater to bring the chamber section up red hot and then turn off when it fires and wait for a cooldown before being ready to turn back on would be an interesting twist.

      1. lithium dropped into water(or the other way around) is a pretty nice bang. i recall a post about a guy who made “weapons” out of things you can buy past the tsa checkpoint, often involving lithium as the propellant.

    1. These have to fall on neighbours than, as you do not want to contaminate yours.

      Maybe kids are reading here so: Batteries are highly toxic, don’t do that at home. HaD should point out this stupidity in the post

  4. When I was a lad I made a firecracker cannon out of a piece of full threaded lamp pipe, about 10~12″ long. I found a ferrule with a smaller hole but it wasn’t small enough so I used some Devcon 5 minute epoxy to glue a small flat washer over the hole in the ferrule. That gave me a breech loading cannon. A couple of nuts secured with super glue kept it from rolling.

    After loading a projectile and a Black Cat I’d light the wick then quickly run behind a large tree.

    For projectiles I used the long inner part from retractable pens. It would punch those right through a slab of modeling clay the same thickness as the palm of my hand – without using wadding, so yes, quite dangerous. I never tried it with anything for wadding. I figured with what it could do with the blowby I didn’t need to risk it blowing apart the pipe by increasing the pressure.

    After the clay slab tests I used it to smash up some junky old 1/64 scale toy cars. The die cast bodies were somewhat damage resistant but the wheels, windows and other plastic pieces blasted away easier.

    I still have the cannon, could probably find it pretty easily. Would likely have to find something different for projectiles as the sort of pens I took apart aren’t so common now.

  5. I think this is pretty cool. It was much more effective than I would have guessed for those match heads. I glad you are willing to post there is the child in all of us wanting to get out and play.

  6. This reminds me of the much smaller and less-dangerous (but, IMHO, more fun) “matchhead rockets” from The Great International Paper Airplane Book, both because matches are used as propellant and because both designs have a layer of metal that is used both to break the ‘fire triangle’ and as a pressure vessel.
    With matchhead rockets, though, a single match is launched at a time, and the layer of metal is only a small piece of foil.

  7. I made something similar (and probably just as dangerous) at school (back in the dark ages)… It used a steel Parker pen refill with the end cut off, and could launch a small steel ball bearing through a gyproc wall. Propellant was either match heads (tended to blow the Parker pen refill into a mushroom after a few shots), or small Chinese fire crackers (now banned in the UK… not as a result of my stupidity so far as I am aware). I failed to collect my Darwin award on that occasion (and several others I might add… detonating camping gas cylinders on an open fire anybody? No? No takers? weedkiller… copper pipe… loud bang.. mud and shrapnel everywhere… metholated spirits related fires… parafin+water in a sealed tin with a small hole in the lid… placed on a fire… All part of the learning process when I was a kid. ), but no doubt if I did as a school kid now, I would end up in the young offenders unit, on a terrorism charge.

    HAD what are you thinking of.. this device looks very unsafe… (/me goes back to flying his kite… in the rain… on top of the hill.. wearing wet copper armour… shouting “All Gods is bastids”)

  8. We used to cut a small hole in a ping pong ball and fill it with as many strike-anywhere match heads as we could. We would then wrap the whole thing in black electrical tape, throw it against a wall and take off. The impact would cause the match heads to rub against each other, igniting them. It took several seconds to build pressure but made an impressive bang.

  9. For what it’s worth, I wouldn’t have folded over the end of the copper pipe. Copper formed into a pipe is quite hard (and brittle as a result). You either have to heat the copper to anneal it before working it or you have to find some other way to put a cap on the end. Seems to me that brazing a pipe cap on the end would be sufficient. It takes a lot of heat to melt your standard brazing alloys – much more than the average propane torch is going to put out.

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