How to Build a Really Cool Potato Gun

Helpful Hint... You may want to line up a couple of buddies to buy the material with you, as the pipes come in 10-foot lengths. All materials can most likely be purchased at a nationally-recognized home materials store with the possible exception of the ignitor (sometimes referred to as a "sparker"). The ignitor can be purchased at any department store with a vast supply of camping equipment.

For best results use schedule 40 ABS plastic. This is the black pipe usually used for sewerage. It is more durable than PVC. The bill of material says 10-foot lengths, because that's as small a length normally sold.

(1) 10-foot piece of 3-inch diameter schedule 40 ABS pipe (You'll actually only need 14 inches per potato gun constructed)

(1) 10-foot piece of 1 1/2-inch diameter schedule 40 ABS pipe (You'll actually only need 36 to 46 inches per potato gun constructed)

(1) 3-inch to 1 1/2-inch reducing bushing (ABS)

(1) 3-inch threaded (one side) coupling (ABS)

(1) 3-inch threaded end-cap (ABS)

(1) can ABS solvent-weld pipe glue (NEVER USE PVC GLUE on ABS!!!)

(1) Coleman ignitor (this item is normally used for putting inside a Coleman lantern for ignition purposes, eliminating the need for matches)

Hacksaw (for cutting ABS pipes to proper length).

Rubber mallet (for construction of gun and for insertion of potatoes when ready for launching).

File (for tapering of muzzle end of barrel).

Drill (for installing ignitor on end cap).

Broom stick (makes a nice ramrod).

Hair spray; the cheaper, the better (used as propellant).

Potatoes (for launching).

Small pipe wrench ("kick back" sometimes causes end-cap to stick; pipe wrench comes in handy to loosen end-cap in such cases).

Construction

Helpful hints... For all steps which involve gluing, follow all can label instructions, make sure the joints are clean first and be liberal enough with the glue to get a seal all around the piping. The ABS glue dries very quickly; so attach pieces together immediately after applying glue. If needed, use a rubber mallet to help in the assembly of the pieces.

Step 1 - The "combustion chamber." Cut off a 14-inch section of the 3-inch diameter pipe.

Step 2 - The "barrel." Cut off a 36-inch to 46-inch section of the 1 1/2-inch diameter pipe (overall length of gun should be determined by whatever you can easily fit into your vehicle for transportation purposes).

Step 3 - Glue the 3-inch diameter end of the reducing bushing to one end of the combustion chamber.

Step 4 - Glue the barrel into the 1 1/2-inch end of the reducing bushing you've glued to the combustion chamber.

Step 5 - Glue the threaded coupling to the other end of the combustion chamber, making sure the glue does not run into the threads.

Step 6 - After the glue dries, use a file to taper the "muzzle" end of the barrel for the last half of an inch on the outside. This will help to cut the potato as it's inserted.

Step 7 - You'll need to mount the ignitor inside the end cap. If you purchased the Coleman brand ignitor, it is threaded and has two nuts with it. An angled piece of metal intended to hold the ignitor inside a lantern is also included. Take the knurled knob off the end of the shaft (be careful - there's an extra flint inside the knob). Unscrew the nut and discard the angled piece of metal. Drill a hole in the center of the ABS end cap (the diameter of the drill bit used should be the same as the diameter of the shaft to be inserted). Mount the ignitor inside the end cap, put the nut on the outside of the shaft and tighten until the ignitor is held in place. The shaft will slide back and forth, but won't come out. Put the end knob back on (with the spare flint inside) and tighten the lock screw.

Step 8 - Make sure the glue has "cured". Let it sit 24 hours before firing.

Step 9 - Make a ramrod. A broom handle works great. Measure from the bottom of the ramrod and mark with highly visible tape about 4 inches shy of the length of the barrel (example; if the barrel is 46 inches, mark the ramrod with tape at 42 inches from the bottom of the ramrod. This will be used as a guide when ramming the potato into the barrel so that the potato is not pushed past the end of the barrel).

Step 10 (optional) - Buy some self-adhesive 1" lettering at your local hardware store. Come up with a crazy name for your potato gun and spell it out on the barrel. My potato gun is known as, and labeled as such... SPUDZOOKA POTATO HURLER 2000 TURBO ZX LIMITED RS7 ALPHA 1 PRO MAX ULTRA MARK III L64^TM.

The spuds will come out with a lot of force! Usual safety about the pointing of guns applies.

Use only hair spray. Never use acetylene, starting fluid (ether), black powder, lighter fluid, gasoline, etc. as a propellant.

To fire: remove end cap. Ram a potato from the muzzle end (use a rubber mallet to avoid injuring hand on tapered muzzle). The tapered-end will cut the potato to size. Make sure it has a good seal as you ram it down with the ramrod. Ram to the guide mark you made on the ramrod. Any scraps of potato that sheared off during insertion of potato should also be dropped into the barrel (this will provide more debris to shoot into the sky). Spray hair spray for 3 to 4-seconds into the bottom of the combustion chamber. Quickly screw in the end cap. Point barrel at a safe launching angle. One or two quick twists of the ignitor knob will send the spud skyward!

Remove end cap. First, flush the combustion chamber and barrel with a garden hose. Then using soap and water, push a small towel through the muzzle end using the ramrod. Once again, rinse with garden hose. Be sure to also clean the end cap.

The author of this page is not responsible for any injuries or damage to property which may result during the construction or use of a potato gun.