by Marilla Mulwane

Created on: February 14, 2013

Using soda bottles to form tornadoes is a classic science project for kids. It teaches kids how tornadoes form, by teaching them about vortexes. The process of swirling the water in the bottle forces air up inside and creates a vortex, much like how a tornado forms.

This "tornado" is created using water, whereas tornadoes on land are vortexes of air without water. Kids can make tornadoes from soda bottles with little help from parents. The bottle tornado is infinite, too. Once the project is complete, the children can keep making tornadoes again and again.

The essential tornado making tools

To make a tornado out of soda bottles, the scientist needs two soda bottles. One liter bottles work the best, but two liter bottles work as well. They just require more swirling and an older child or adult might need to help. Smaller bottles are not recommended. The water pours out quickly, and if the young scientists use small bottles they won't see the tornado for long.

What else is needed? Water. The difficulty in making the tornado is attaching the two bottles together. There are several options, and the young scientists and their adult helpers can choose what works best for them.

Attaching the tornado bottles together

For the project, the two soda bottles are attached together one on top of the other. One bottle points down and the other points up, connected by the opening. One way to do this is to drill a 1/2-inch hole in the top of each soda cap. The small hole is what helps create the vortex, so do not make a hole bigger than 1/2-inch.

Place the caps together top to top so that the holes match up. Tape them together with duct tape, but do not put tape on the ends. The caps have to go back on the soda bottles. When they are back on the bottles, it looks like an hour glass.

Another way to make the "hourglass," is to not use the caps at all. Simply place a washer the same size as the bottle cap between the two bottles and duct tape them all together. Make sure to use plenty of tape and to make sure the necks of the bottles are sturdy. When not using the bottle caps, the tornado maker is often a bit wobbly.

Finally, the easiest option is to purchase special tornado tubes which are two caps with a hole in the middle. They were made for this purpose alone, and are available at toy stores, crafts stores, and online.

Making the tornado

Fill one bottle with water. Screw one end of the double cap onto the bottle and stand it up straight on a sturdy table. Attach the second empty bottle upside down on top of the first bottle. Make sure it is tight.

Quickly flip the bottles over, as if using an hourglass. Hold on to the bottom bottle and swirl the top bottle with the other hand. Swirl quickly and in wide circles. Stop swirling after about 30 seconds and watch the tornado. Once the water completely empties into the second bottle, flip it over and go again.

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