Kevin Kohler, aka The Backyard Scientist, is widely known for his unique experiments and projects that often result in something exploding, melting or being burned, which applies for one of his more recent projects–the Flame Sword. As the title suggests, the sword is literally ENGULFED IN FLAMES as Kevin uses it to mutilate a perfectly delicious looking watermelon.

Kevin begins the build by using a toy foam sword as a mold to cast into aluminum, which he does by first inserting a steel pipe into the sword (for rigidity) and then encasing it in plaster. Once dry, he then puts it into a bucket of sand to keep it level (and reducing the chance setting his surroundings on fire). Afterwards, he pours molten aluminum into the hollow end of the foam sword, which burns away the foam leaving only the cast aluminum with steel rod inside.


Kevin then goes to town drilling holes (34 of them) along both sides of the blade to allow the propane gas to escape and lit on fire. He sanded and polished the blade to clean it up and give it a more authentic flame sword appearance. Once cleaned up, a tube connected to a propane tank is inserted into the end of the sword with a snug little fit, preventing the gas from escaping.


If you’re following along at home, you’re ready to IGNITE THE SWORD. No special chant or summoning here, Just crank on the propane and light it up. Kevin did so, demonstrating the sword’s magnificent flame imbued power ot slice and dice a large watermelon and its innocent tree trunk friend. Suffice it to say, he couldn’t hold onto the pure metal flaming sword for very long, as aluminum tends to heat up when exposed to flame after only a few minutes. Yep.

Follow the video and steps below to make your own, just remember to add a heat-resistant grip. Flame on!
















The one-man ace engineering wrecking crew - If you have a problem, if no one else can help, and if you can find me, maybe you can hire... the Cabe-team.