Build a Mini Water Gun

Materials you'll need

• Empty plastic bottle
• Spray bottle pump head (removed from a recycled spray bottle)
• Clear plastic tubing, flexible and thin
• Drill with a small drill bit
• Hot glue gun and glue sticks
• Water

 

Step-by-step tutorial

Step 1: Remove the pump head from a recycled spray bottle by unscrewing or pulling it free. 

Step 2: With adult help, drill a small hole near the bottom of your empty plastic bottle. 

Step 3: With adult help, use a hot glue gun to glue the pump head to the side of the bottle. 

Step 4: Bend one end of the tubing through the hole you drilled in the bottle's side. Then seal around the tubing with more glue. Let the glue cool completely before moving on.

Step 5: Fill your bottle with water.

Step 6: Screw a bottle cap to the top of the bottle, then take it outside and squeeze the trigger.

Learn more

Your DIY water gun works the same way every spray bottle does — using pressure and one-way valves. When you pull the trigger, a small piston inside the pump pushes water through the tubing and out the nozzle in a focused stream. When you release the trigger, a spring pushes the piston back, creating suction that draws more water up from the bottle. Clever little valves called check valves make sure the water only flows one direction — up and out — so it never slips back the wrong way. The narrower the nozzle, the more focused (and farther-reaching) your stream.