Half-inch PVC pipe is drilled and glued together into a giant, 3-foot long “T” that will launch 1- and 2-liter bottles over 100 feet in the air. Once your launcher is assembled, all you have to do is fill the bottles half full with water and wiggle them on to a threaded riser. Using a bicycle pump, you quickly fill the bottle with air until the pressure inside overcomes the friction holding the rocket in place and it shoots into the air. Repeat as many times as you want; all you need is a source of water, someone willing to work the bike pump, and a recovery team to chase down the rocket body. Comes with all the parts you need to assemble the launcher. You need to provide the bottle, water, and PVC cement.
LL Demos & Labs: Water Rockets