Spooky Hovercrafts

Make a spooky balloon hovercraft that floats across a table on a cushion of thin air.

things you will need

Balloon
Push-up bottle cap (from a drink or washing up bottle)
CD
Glue (preferably hot glue)
Pens (to decorate your balloon)

Prepare the bottle cap

If you are using hot glue, ask an adult to help you out with this step.
Open the bottle cap and turn it upside down.
Apply glue all the way around the rim of the bottle cap.

Glue the bottle cap to the CD

Place the bottle cap onto the middle of the CD.

Assemble your hovercraft

Close the bottle cap.
Inflate the balloon and pinch the base of the balloon leaving about 2cm.
Stretch the 2cm tip of the balloon over the bottle cap.

Get creative

When inflated, use a pen to draw a spooky face on the balloon.

Time to launch

Place your spooky hovercraft on a flat, smooth surface (a polished table works great!). When you are ready, pull the cap open without removing the balloon.
Whoosh! The hovercraft will float on a thin cushion of air.
Can you make a few and race them with your friends?

How it works

When you open the bottle cap, the air inside of the balloon is forced downwards through the hole in the centre of the CD. This creates an opposite upwards force from the surface of the table to the CD, which lifts your hovercraft off the surface.