Mike, Vern Knowels is a rocketeer from the northwest (Idaho) who has an amazing website with all kinds of information. He chronicles his building of several rockets and includes a wealth of information about things like this. He also explains how and why which I find very helpful. I recommend you give his site a visit...but plan on staying awhile! Oh, he also has some great videos and pictures. Www.vernk.com Sent from Yahoo! Mail on Android