I'm sure many of you have seen the little tube/connectors you can use to connect two 2-liter soda bottles to make a tornado tube. Like this:
I've wondered at various times, whether one could create the tornado tube without that little plastic connector, which I don't happen to possess, and while quite inexpensive, have never gone ahead and purchased.
I was pleased to find instructions for creating my own tornado tube in Janice VanCleave's 202 Oozing, Bubbling, Dripping, and Bouncing Experiments.
The materials you'll need:
--a flat metal washer - one that's the same size as the mouth of the bottles
--two 2-liter soda bottles
Fill one of the bottles half-way with water (feel free to add a little food coloring and/or glitter, if the mood strikes you).
Tape the bottles together with the duct tape - don't skimp, make sure things are secure!
Turn the bottles upside down. With one hand on the top bottle and the other on the bottom, move the top bottle in a small circle.
Set the bottles down and watch the tornado vortex form.
I was pleased with how well the tornado formed. However, despite my best taping effort, some water leaked out every time we used it. If it's something you're going to do repeatedly, it's probably worth a couple bucks for the special coupler. If it's likely a one-time thing, this definitely works and is less "stuff" to have around the house.