How to Make a Water Bottle Balloon Car

A balloon car made in a bottle utilizes the principle of rockets. Air is compressed inside the bottle which is allowed to escape through a narrow nozzle. The resultant thrust propels the balloon car forward. This science project experiment is an excellent way of recycling old plastic water bottles too.

Water Bottle Balloon Car
Water Bottle Balloon Car

Building a Balloon Car with a Bottle


  • Plastic water bottle
  • Wooden barbeque skewers
  • Wire Cutters
  • Balloons
  • Scissors
  • Plastic bottle caps
  • Knife
  • Glue or marshmallows
  • Straw
  • Tape


  1. Take a small sized bottle and rinse it clean.
  2. Use the wire cutters to snip a couple of 4” pieces of the wooden barbeque skewer. It will serve as the axles.
  3. With a sharp knife, pierce two tiny holes on each side of the bottle, one at the bottom and another on top having suitable diameters for fitting the axle. They are to be made at an inch from the ends at even levels. There should be four holes in total.
  4. Slide the axles through the holes such that they sit parallel to each other.
  5. Use four small plastic bottle caps as the wheels. Fix them at the ends of the axles with glue or marshmallows.
  6. Push the straw by about 1 inch into the balloon. Use tape to secure the junction. The nozzle is complete.
  7. Lie down the bottle horizontally on a surface. Using the knife cut two slits perpendicular to each other (in the shape of an X) on its upper surface. The slit should be placed about four inches from the bottle mouth.
  8. Thread the nozzle through the opening described in the previous step and make it go out through the mouth of the bottle. An inch of it should stick out of the mouth.
  9. Blow air into the balloon through the free end of the nozzle.
  10. After filling the balloon with air, put your finger at the free end of the straw to stop any air from escaping.
  11. Once you are ready, let go of the straw to allow the car to race.

Water Bottle Balloon Car Science Project: Video

This DIY car is suitable for displaying at science fairs. Made from simple ingredients, the project needs minimal adult supervision. Kids are going to love the balloon part of this fun activity.


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