This was my initial design for the compressed air rockets. I used duct tape to provide extra strength because they kept blowing out from the air. The rockets are made with the front and back of a magazine wrapped around a pvc pipe and then taped with duct tape. After that I put a cardboard circle on the top (before the nose cone), and add tape to cover it. The fins are made out of cereal box cardboard, and the nose is also.
They take about 15 minutes to create and so far they last pretty long before getting to damaged (one reason is crashing on landing, which I hope to fix with a payload type rocket).
I found a document online explaining how to create payload rockets for compressed air rockets, so I started to build one. I have only built the body so far, I still have a lot more to go on this rocket. Once this one is built I will post some pictures and will also report on height. The new rocket is about 3 copy paper pages wrapped around PVC with glue between each sheet. On the outside the whole body is covered in a few layers of clue (to make them stronger).