thats ez, take any 2 liter bottle, cut a small hole about 2/3s down, then disassemble a pen and stick the shaft into the hole(yes that sounds dirty ) and seal it with wax, make a reasonable size bowl out of tin foil and put that on side of the pen thats on the outside, then put water inside till its up to the hole(make sure its over the hole of the pen inside), then u have a pretty good bong