Pressure Bottle Rocket

Water squirters work by pressurizing reservoirs of water with air. As you pump the squirter, it gradually adds air to the reservoir, increasing the pressure. When you pull the trigger, the pressure is allowed to release and a stream of water shoots out!

In this DIY project, we'll learn how to use the exact sample principles found in water squirters to launch a water rocket sky-high! Follow along with these simple steps and you'll be blasting off in no time.

Want to make a bottle rocket without the hassle of gathering materials? Blast off with a Bottle Rocket crate from the KiwiCo Store! It includes a step-by-step video tutorial link, illustrated blueprint instructions, all the materials, and a special-edition Tinker Zine magazine for more project fun!

  1. Ages: 9 - 16

  2. <30 minutes

  3. Messy

  4. Grownup needed


Materials you'll need

Step-by-step tutorial

  • Step 1

    Drill a small hole through the center of your cork stopper. The hole should be just smaller than the diameter of your pump needle.

    Photo reference of how to complete step 1

  • Step 2

    Wrap your cork in electrical tape until it fits snugly in the bottle opening.

    Photo reference of how to complete step 2

  • Step 3

    Press your pump needle through the hole in the cork. Make sure the thicker end of the cork is pressed on first.

    Photo reference of how to complete step 3

  • Step 4

    Use a small piece of clay to seal the cork around the pump needle. Make sure you don't clog the needle opening.

    Photo reference of how to complete step 4

  • Step 5

    If you'd like, create rocket fins and a nose cone out of scrap plastic or coated paper. Color them with a marker to give your rocket some extra pizzazz!

    Photo reference of how to complete step 5

  • Step 6

    In preparation for launch, fill your bottle part-way with water.

    Grab a friend and find a wide open space to launch your rocket. Have your friend press the cork into the bottle and flip it so the nose cone is pointing upwards and away from you. The bottle should gently rest in one hand and the pump should be firmly held in the other.

    When your friend and rocket are ready, start pumping! The pressure will start to build and after a few seconds, your rocket will blast off into the air!

    Photo reference of how to complete step 6

  • Learn moremagnifying icon graphic

    What’s going on?

    The pressure bottle rocket works thanks to Newton’s third law of motion, which states that for every action, there is a reaction. As you pump up your rocket with air, pressure builds up inside. Eventually, this pressure pushes the rocket off of the cork and bicycle pump, and expels the water in the bottle downward — this is the action. The reaction to this downward movement of the water is the rocket’s own upwards movement, sending it high into the sky. 

  • Factmagnifying icon graphic

    The world record for the greatest altitude achieved by a pressure bottle rocket (using only water and air) is 2,723 ft (830m) - which is just over half a mile! It may be simple, but the pressure bottle rocket is quite effective, and it is the basis for the design of rockets that are launched into outer space.

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