How to Make a Bong From a Plastic Bottle
I've made probably two dozen of these over the years. Most people throw one together on a camping trip or when they're stuck somewhere and can't buy anything. The basic idea is simple: a 2-liter soda bottle becomes the body, a smaller bottle or PVC piece becomes the downstem, and you add a makeshift bowl. It filters smoke through water and gives you a rough draft. That's the whole thing. Grab a clean 2-liter bottle. Any plastic soda bottle works, though Pepsi and Coke bottles are usually sturdier than the cheaper generic brands. Cut off the bottom about three inches up from the base. You now have a cup shape. Cut a hole in the side about two inches above where your cut ended — this is where the bowl attachment goes. The hole should be roughly the size of a standard lighter or a small PVC connector. Drill or melt a series of tiny holes in a circle around the opening for airflow. For the downstem, use a smaller plastic bottle (like a water bottle neck) or a short piece of 1/2 inch PVC. Push it through the hole you cut so it angles slightly downward into the bottle. The bottom of the downstem should sit about an inch above where the water line will be when you fill the bottle. This is where most people mess up. If the downstem is too low, you get splashback and awful tasting water. If it's too high, the filtration barely does anything. Fill the bottle about a third full with water, insert the downstem assembly, and seal the seam with hot glue or duct tape. Pour a bit more water in to test the seal. If it leaks, add more tape or glue.
The bowl piece is the trickiest part. I use a metal lighter cap with a piece of screen soldered or taped across the opening, then attach it to the downstem with a rubber band. Some people cut a small section from a different bottle and use that as a bowl holder. The key is getting a tight fit so smoke doesn't escape around the edges. I once spent forty minutes trying to make a bowl piece from a aluminum can strip and it just wouldn't hold shape. Ended up using a modified pen cap instead — works just as well and takes about five minutes to fashion. Here's something most guides don't mention: the thickness of the plastic matters more than you'd think. A thin Walmart brand bottle will collapse under the suction of a hard pull. Stick with anything that has a ridged or reinforced sidewall. Also, don't skip the ice catcher. Cut a second ring from the neck of another bottle and drop it inside about an inch below the mouthpiece. It traps condensation and keeps water from shooting up your throat. I learned that the hard way after my first build — turned into a face full of cold water on the second hit. These things last maybe an hour before the glue softens or the plastic warps from heat. They're disposable by design. If you're doing this seriously, a glass rig or even a simple bucket bong is a better investment. But if you need something right now with what's in your trash, a plastic bottle bong gets the job done.
