Or, if you can get a rounded bowl peice for like a slider bong, you don't need to use a socket or a cap, and it works much easier.
The rounded bowl uses suction to sit on top of the bottle without leaking, and when you've pulled the bottle as far as it can go, no messy unscrewing, just simply pluck it off. And no nasty metal.
Inferius Reviewed by Inferius on . Creating a Gravity Bong So, I've smoked out of all sorts of things, but not a gravity bong yet. I want to get the setup down for 4/20, so I want to make and use one this Friday. Now, I know I need the following: 2-liter bottle (with lid to affix the bowl to) Some sort of socket thing for the bowl (I already own one of these) Something to connect the socket to the cap (I used a pen cap last time, see below) Bucket to submerge the bottle in Here's the deal: This past summer, I made a waterfall bong. I used a Rating: 5