I built mine almost like yours. The only differences are that the peice of PVC pipe is 7.5 inches, but it ended up being about a foot tall with the caps and everything. It is really heavy too. The cannister is a juice can full of BB's and a couple of nickles and pennys(about 5 in total). Now all i have to do is find a place to mount it and figure out a way to do so. I'll probably have it in the car ready by sunday. Did you put silicon or teflon tape on the thread of the screw cap to seal it completely?
