If you are assigned a science project on whirlpools or tornadoes, you can use recycled 2-liter bottles to replicate both of these natural phenomena for your presentation. Many science museums, educational stores and novelty shops sell kits for making these projects, but these are a wholly unnecessary expense. The parts they provide can be replaced with a common rubber washer. So, save your money, and make your own inexpensive water vortex or tornado science project using common household items and recycled materials.
Wash out the insides of two 2-liter soda bottles with warm water and two drops of dish soap. Fill the bottles with warm water and seal with the caps. Shake the bottles vigorously, and dump the water out. Repeat until no suds remain.
Tear the labels off the bottles and discard them, along with the bottle caps. Fill one of the bottles about three-quarters of the way full with water. Dry the mouth of this bottle off with a small towel. Apply a thin strip of rubber cement around the top of the mouth. Press a rubber washer with a 3/8 inch diameter hole onto the mouth of the bottle. Allow the rubber cement to dry.
Dry off the mouth of the empty bottle. Apply a thin strip of rubber cement around the mouth of this bottle, flip it upside down and press it down onto the rubber washer. The mouth of the empty bottle should be flush with the mouth of the bottle containing the water. Hold the empty bottle in place while the rubber cement dries.
If the rubber washer extends beyond the mouths of the bottles, cut the excess off of the washer with a razor blade, then run the blade around the mouths of the bottles to make the washer flush with their edges. Spread a thin layer of rubber cement around the washer and the mouths of the bottles. Allow the rubber cement to dry.
Wrap the area around the mouths of the bottle with duct tape. Work slowly and press the tape against the plastic bottles to form a tight seal. Tilt the bottle contraption on its side so that some of the water is at the mouths of both bottles. Slowly rotate the contraption and check for leaks. If any leaks present themselves, continue wrapping duct tape around the bottle mouths until no more water escapes.
Flip the contraption upright so that the bottle full of water is on top. Watch the water turn into a vortex as it flows from one bottle to the other.
Add things like glitter and food coloring to the water for a more visually appealing project.