How to make a potato cannon

This how to video describes how to make a potato gun. First get a 2ft long 2 inch wide PVC pipe, an adapter that goes from 2 to 3 inch ABS pipe, a 1ft long 3 inch wide abs pipe
and a coupler with a cap on the back. Then get a bbq ignition lighter and set up the wires like a spark plug. It would cost you about 30 dollars to make one including glue, pipes, and the bbq ignition.