Hydrogen Desk Cannon Is Fun With Electricity and Water

Water is a stable chemical, but with the addition of a little electricity, it can be split into its component parts. The result is just the right mix of H2 and O2 to convert back into water with a bang. [Peter Sripol] has built a charming desktop cannon in just such a way.

The build consists of a contact lens canister filled with a solution of water and potassium hydroxide. By running a DC current through this solution, oxyhydrogen is produced, which then passes through a flash arrestor and into a combustion chamber. Upon the chamber is affixed a rocket, which is propelled when the charge is lit by a piezoelectric ignitor.

The chemical side of the build was easy, but it took significant experimentation to get the rocket side of things working well. Eventually success was found by creating a blast cap out of paper and hot glue which allowed the energy of the blast to be more effectively transferred to the rocket body. With this in place, the cannon is capable of firing small paper rockets in excess of 20 feet.

With the brass and copper components mounted upon stained wood, this contraption would look beautiful on any desk and would be great for assailing one’s fellow coworkers. If your office doesn’t have an explosives policy yet, once you bring this in to work, it will soon. [Peter] uses similar technology in his Nerf blasters, too. Video after the break.

12 thoughts on “Hydrogen Desk Cannon Is Fun With Electricity and Water

    1. Actually, both are poisonous if there is too much in the lungs for too long, not to mention that a lung full of H2 (atomic H quickly becomes molecular H2) is explosive. That may seem counter-intuitive for molecular oxygen, O2 (note that atomic oxygen O is EXTREMELY reactive!), but oxygen levels much higher than the normal 20% level we’re used to, can cause cellular damage (see https://en.wikipedia.org/wiki/Oxygen_toxicity).

      Hooray for ubiquitous dihydrogen monoxide – we just can’t live without it (and a little C2H5OH every now and then ain’t bad either).

  1. Interesting concept, like the small scale of it and the brass and wood really give it a nice touch. Most of the time I’m not into this that burn and are potentially dangerous but this is something completely different. More slowly and controlled, yet not totally harmless. For some reason it reminds me of those little desktop steam machines. Fun project and informative video.

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