Outside over-the-top action movies like Mad Max, you won't see flamethrowers very much these days. Liquid- or gas-based flamethrowers were used extensively in WWI, WWII, and the Korean and Vietnam Wars. But due to restrictions from the Geneva Convention and the extreme danger associated with wearing a large tank of flammable fuel on a battlefield, these incendiary weapons are no longer a part of conventional military warfare.
However, that's not to say that they're no longer effective. As we've said before, prison inmates often invent deadly improvised weapons from limited resources, and these aren't just limited to shanks. Believe it or not, inmates have reportedly fashioned crude flamethrowers which don't run on liquid or gaseous fuel. C.T. O'Reilly, the Assistant Warden of Darrington Prison in Texas, once told a reporter, “The inmates would roll up a piece of paper, put Coffee-Mate in it, put a cigarette lighter in front of it, blow it out and it's just like a flamethrower.” This apparently led to all powdered creamer being removed from the commissary at Darrington.
These powder-based flamethrowers disperse a cloud of combustible material — such as flour, cornstarch, or coffee creamer — and enhance its ability to burn quickly. It's the same principle which sometimes leads to deadly dust explosions in industrial environments, and was demonstrated on the Mythbusters TV show “Creamer Cannon” episode.
While we definitely would not recommend trying this at home, it's possible to make a flamethrower by simply blowing a cloud of flour through a tube and across an open flame. If no other weapons were available, this could provide a last-ditch improvised means of self-defense. Or, the concept can be taken to the next level as shown in the video below:
These guys cobbled together a leaf blower, a hand-crank powder dispenser, some PVC pipe, and a blowtorch to create an incredibly effective improvised weapon. It might not be a military-grade flamethrower, but we'd be willing to bet no attacker would want to get anywhere near the business end.