How to Make a Potato Gun: It’s Cheap, Easy, and Certainly Amusing

Have you ever had the desire to see a raw potato explode upon impact after it goes whizzing through the air and smacks into a wall? Probably not. It doesn’t rank high on many peoples “things to do” list. On the other hand, the desire to obtain this outcome with the use of cannon may be a bit more enticing.

A Potato launcher is a simple home made gun designed to fire a potato or an object roughly the size of a potato. Now while this is just a plain device, it does pack a decent punch and, if it is properly made, the results of it can be a bit surprising. These vegetable shooters have the ability to throw a potato a few hundred yards across a field, and the shot is accompanied by a rather satisfying boom.

The basic ingredients in the potato gun recipe are fairly inexpensive and can be found between things lying around the house and the local hardware store. Making the cannon itself requires only two types of materials; plastic PVC pipe (generally found in the plumbing section of a hardware store) and the wiring and ignition switch from a propane grill (generally found on the grill sitting outside that hasn’t worked for six months).

There are four pieces of PVC pipe required, and the pipe purchased should be made of fairly thick plastic; after all it is going to shoot something. The gun needs one solid piece of tube, roughly six inches in diameter and eight inches in length. This piece will serve as the canister which will hold the charge. Next find two end caps for the canister piece. One must be just a solid end cap, and one must be a cap that has the ability to open. This is generally found in the form of a cap with a lid that is able to unscrew. These two pieces will serve to enclose the canister. Finally, a three foot piece of tubing with a diameter between two and three inches will become the barrel.

To assemble, attach the two caps to the ends to the canister piece. Check to make sure the end with the unscrew cap is easy to open, but also that it seals tightly when fully shut. Next, in the solid piece end cap, cut a hole in which the barrel will be inserted. The hole should be cut slightly smaller than the diameter of the barrel piece to help make the gun as air tight as possible. Wedge the barrel a few inches into the canister and then put a seal around the hole as well as the two caps on the canister. Preferably, some sort of plumbing sealant should be used to fill in any possible air leaks, but honestly, a few layers of well placed duct tape will do the same job. The complete the gun; insert the grill igniter by cutting a small hole in the canister and placing the ignition wires inside the tank. Remember to seal around this hole as well. The ignition button will serve as the trigger.

Now the gun is built and there are only two items left to obtain; the one that makes it shoot and the one that shoots. Obviously it is time to get potatoes, so either go to the store and buy them or harvest the potato plants that have been growing in the back yard. Now for the power house of the design, the motivating force behind the flying potato. Hair spray. Surely it doesn’t seem like part of a cannon, but think about what happens when a lighter is held in front of a stream of hairspray and this device can be easily understood.

To fire this newly made toy, insert a potato into the barrel of the gun. Remember not all potatoes were created equally, so don’t expect them to slip smoothly into the barrel. The best method is to just smash one in as far as possible by hand and then use a stick or poking device to push it down a foot or two into the barrel. Be careful not to push it all the way into the canister. Next, unscrew the end cap, fill the tank with hairspray, and quickly re-seal the cap. The amount of hairspray needed will vary between each gun, but it is something the shooter will become accustomed with after the first few tries.

The potato cannon is now ready to be shot. Aim the gun at a safe target and push the ignition switch to fire. Take the next second or two to stand back and watch the shot while struggling to hear it hit through ringing ears.

The gun works on a very simple principle: pressure. When the ignition switch is hit, the wires inside the canister spark, just like they would to create the propane fueled flame of a grill. Only now, it is sparking inside a small tank filled with a combustible compound. The spark ignites the hairspray and the explosion, held in the barrel by simply a wedged potato, blasts its way out turning the potato into a projectile.

Remember, while this is just a gun that shoots vegetables and fruit, it is no toy. A potato cannon should not be used to shoot at anything other than a safe target. Always practice safe shooting procedures while firing. Enjoy the spud launcher.