How to Make a Foam Dart Gun

Make a water-pressure powered, foam dart gun. The gun will allow you to not only shoot a dart but also to follow up with a jet of water to drench your opponent. The darts can also be modified for greater distance to use on (non-living) targets. This foam gun is perfect for a hot summer day of fun in the back yard.

Difficulty: Moderate

Instructions

Things You'll Need:

• Garden hose sprayer
• PVC pipe
• Epoxy
• Foam swimming noodle
• Knife
• 12-inch dowel rod (1/2-inch diameter)
• Safety knife (box cutter)
• Garden hose

1. Get a garden hose sprayer. It is also called a spray gun because it looks like a gun except that it has a trigger on the back of the handle. When the handle is depressed, it sprays water out the barrel of the sprayer. When you buy this, use it to find a PVC pipe that fits tightly over the barrel of your sprayer. Pipe size will vary by sprayer.

2. Cut the PVC pipe that you buy to a one foot length. Slip the sprayer into the pipe to see how far it will go. Coat the inside barrel of the sprayer, where the sprayer will slide in, with epoxy. Follow the instructions that come on the Epoxy container when you do this. Slip the PVC pipe over the barrel of the sprayer. Hold the pipe in position and wait for the epoxy to cure and harden.

3. Get the pool noodle. Press the end of the pipe into the noodle to make a slight impression. Carefully use a sharp knife to cut out this cylindrical foam to make a dart plug. Check the fit in the barrel by inserting the foam half way into the barrel. Turn the plug around and insert it to check the fit of the other half. Cut the plug until it fits well. Slice the plug like a loaf of bread into 2-inch thick pieces.

4. Screw on the garden hose to the handle of the sprayer. Use the 12-inch dowel rod to push the plug into the end of the pipe and all the way to the tip of the sprayer. Turn on the pressure briefly (one second, short burst) with the barrel pointed away from yourself. Unhook the hose from the handle and look into the tip to see if the plug moved. Shave down the sides of the plug with a safety knife (box cutter) until the plug fits loosely into the barrel. After this, do not use the dowel rod.

5. Cut a slit down the side of a section of noodle that you cut 12-inches long. Slip this section over the PVC barrel so that it does not obstruct the end of the barrel. If desired, tie the foam tube onto the PVC with dental floss.

Tips & Warnings

• To make the projectile go farther, hollow out the foam and add a small rubber "bouncy ball" to the inside but do not point this at people, animals, or breakable items because of the increased power. If the plug gets stuck in the barrel, use a wire coat hanger to "corkscrew" out the plug.
• Be careful with all sharp items. Do not make the plug fit tightly into the end of the pipe, or the pipe may burst. The pipe may have sharp edges that could cause injury if not used appropriately. Never point this at a person if the projectile can go more than 25feet. Never point this at a person that is fewer than 5-feet away. Wear swim goggles to protect your eyes when playing with this device. Never put anything into the barrel but the foam dart when the hose is hooked up. Do not put the dowel rod into the barrel when the hose is hooked up. Wear safety goggles when working on this project. Read and follow all instructions that come with your tools. Use only under adult supervision with a person that is mature enough to read and follow all safety instructions.

Resources

• Spud Gun
• Air Duster Gun
• Chopstick Crossbow