i made my first set of bombs and they worked well but i am going to have to work on the durability factor. my biggest problem is i was not able to locate any of the 2 part polyurethane foam described by chuck. i have since found the materials online but i needed it by last weekend so i tried "great stuff" in a can used for home insulation. this resulted in failed experiment #1. in my first attempt with the foam i just filled the bomb up with the foam and let it sit a day. the back end was hard so i tried dropping the bomb about 2 feet, that resulted in all the foam except the top 2 inches to colapse into a liquid mess in the bottom of the bomb. after cleaning out that mess i tried again spraying 1 inch then letting it harden then repeating over and over till full. here is a couple pics of my first finished bomb. they don't look overly large because of the size of the airplane, but they are about 15 inches long.[img][/img]