Make huge water rockets by joining multiple bottles together using this tutorial. If you want to see the Webpage version of this tutorial, please visit: http://www.uswaterrockets.com/construction_&_tutorials/bottle_splice/tutorial.htm This tutorial shows you how to join multiple bottles together to make a Huge Water Rocket using our Slip Joint Splicing Technique. This easy new method of joining bottles creates strong and attractive joints by reducing unnecessary and/or detrimental steps from the traditional splicing techniques commonly used. Our testing shows these splices typically hold past the point where the other areas of the bottles become permanently damaged from the plastic stretching (which varies with different size bottles). On 500ml bottles, we have seen 195PSI sustained with this method.