Homemade propane rifle cannon shoots like a sci-fi weapon

Science is fun ! Especially when it is used to make a homemade cannon that bet so cool when it fires . This guy rope connected a self - igniting propane torch to some tube and then color the flame so that it pops off immature when it blasts . It bet like an alien ’s weapon !

The Backyard Scientist pen :

The blowlamp is ego - wake , meaning it has an galvanic spark arrester build in . When the button is pressed halfway , the torch mixes a everlasting combining of propane and air travel into the tube . When the release is fully pressed the torch sparks sending a flaming flying through the tube . I tried to colour the flame with some boric acid , and it turned hopeful green .