Download the Water ... bottle? Look for air bubbles in the water when you pump. If no, make sure the valve can open to let air through from the pump. It may be damaged or screwed shut. If the ...

This water rocket launcher lets you do just that. Built using the frame from an old grill, a soda bottle takes its place ... also pick up some extra PVC to make this pressurized water cannon.

This piece of engineering is so simple and elegant, you’ll want to build a pretty serious water rocket ... the bottle. The staggered tongues that are left after cutting along this line make ...