How to Build a Water Rocket

Building a water rocket is a lot of fun as well as fairly simple. Water rockets are a great way to teach some basic scientific principles to your children like Newton's Laws of Motion. They also are a great way for both children and adults to just enjoy themselves.

Things you'll need:

Bike pump

 Water

    1.  Build the Rocket

 

Insert a 2-inch piece of 1/4-inch flexible copper tubing into the hole in the stopper. Apply glue to the hole of the stopper so that the tube will be secure, but be sure to not clog the tube.

Slide the end of a 2-foot section of 1/4-inch plastic tubing over the copper pipe and glue it in place. For extra strength you should also use a tie wrap to secure the plastic piping to the copper pipe.

Affix the bike valve stem to the other end of the plastic tubing. Glue this joint and use a tie wrap if necessary for strength.

2.  Build the Launcher

Saw the 4 feet of 2-by-4 into 2 2-foot sections.

Hinge the 2 2-foot sections of 2-by-4 together end to end.

Cut a 2-liter bottle in half from the top to the bottom. This will make a chute to set your rocket in. This chute will guide the rocket when it is launched.

Trim the bottom of the guide chute so that it will not catch the bottleneck when it launches.

Screw the launch chute onto one of the 2-by-4s.

3.  Launch the Rocket

Fill rocket halfway full with water then affix the stopper tightly to the bottle.

Stand up the launcher so that it is pointing in a safe direction.

Turn the bottle upside down and place it into the launcher chute.

Attach your bike pump to the valve stem and start pumping. Eventually the rocket will build enough pressure to release the stopper and fly!

Tips & Warnings

      Replace the bottle after a large number of launches as it is possible for the bottle to weaken over time.

      Sometimes you will not get the rocket to launch. Instead, it will only spray around the rubber stopper. Use caution if you go to touch the rocket as it is still pressurized and can launch if touched.

      Water rockets can travel at a high rate of speed. Do not fire them in the direction of homes, animals or people as property damage or injuries could result.