The Spud Gun

Allow me to explain. The spud gun fires potatoes (or anything else that will fit into the barrel and make a good seal) high into the air. That's all it does. And some days, you just need to do that...step out the back door and blow something away.

My spud gun uses compressed air, routed through a water sprinkler valve and powered by three 9-volt batteries.

Here is what you need: Go to Home Depot and get a 10-foot section of 2-inch PVC pipe; a 10-foot section of 1-inch PVC pipe; a Rainbird water sprinkler valve; 2, 2-inch PVC coupler fittings; 2, 2-inch PVC male fittings with 1-inch PVC female ends; and 3, 1-inch PVC female fittings with 3/4-inch, male threads. Also purchase a 2-inch PVC end-cap. While you are there, also get a roll of white, Teflon thread tape.

Buy two switches...push button switches are best. I went for "cheap" and used two regular home-style wall switches. Purchase one small can each of PVC primer and glue. From Radio Shack, buy a package of 9-volt battery connectors....five to a package, and three, 9-volt batteries. Purchase from a NAPA auto parts store one 1,1/2 inch long automotive, bolt-in, tire air valve stem.

Cut two, 2-inch pieces from the 1-inch PVC pipe to join the last two pieces mentioned (look at the photo).

For the barrel, cut the 2-inch PVC pipe to approx. three feet in length. Cut a second barrel slightly shorter for the air chamber. Drill the proper size hole in the end cap and bolt in the air stem. Using proper gluing technique, glue the end-cap to one end of the air chamber. Glue the reducer pieces to the ends of both, the air chamber and barrel.

Apply Teflon thread tape to the threads before screwing into the sprinkler valve. Wire three 9-volt battery connectors in series through two switches to the wires for the sprinkler. The second switch is for the sake of safety.

I made a wooden frame to surround the head of the sprinkling valve. The switches can be taped to this frame.

After gluing, it is very important to wait 24 hours before using. The joints can blow apart and cause serious injury if not fully cured.

With a round file, or grinder, file a bevel on the inside of the barrel to help with inserting said potato. Shove the potato all the way down. With bicycle pump, or suitable air source, inflate the air chamber to no more than 140 psi. Point it in a safe direction and activate the switches. The potato should fly approx 150 yards.

With the remaining 1-inch PVC pipe, glue the third 1-inch PVC fitting with 3/4-inch threads onto that pipe. I cut mine to approx. 6-feet in length. This second barrel is good for firing carrots, small potatoes, apples, or whatever else you can think of that will fit.

The solenoid in the water sprinkler valve operates on 20-volt, DC current but handles 27 volts fine.

A friend asked if "dog doo" from his neighbor's dog would work? I assured him it should make a nice impression on the side of his neighbor's garage. But don't forget...this is a dangerous device and not a toy.

These air cannons have been used as "confetti blowers" at celebrations and as launchers for paintballs. Another use was to launch an emergency Ham radio antenna into tree tops. With some imagination, many household items can be launched high into the sky.

Why?

Sometimes a guy just needs to step out back and blow something away.