how bout you take a socket, put it on the end of a gutted bic pen, then heat up a spot on a bott,e and when it turns white and startes to melt you push the bic through it. the cut a hole on the other side for a carb. the pushing a bic through hot plastic works really good for an airtight seal. just gotta make sure the socket is airtight on the pen. the you put enough water so the end of the pen is under about an inch, (pen should enter bottle at an angle). put a pebble in the socket and then some weed and you have a bong.