A few years ago my friend's mother started using medical marijuana for pain management. My friend had to explain that no, you should not make a pipe out of a coke can because of the plastic liner, go to a head shop and buy a glass pipe like a normal person!
> you should not make a pipe out of a coke can because of the plastic liner
I'm fairly sure it doesn't make much of an health impact considering the hot smoke you pull into your lung, but when I was kid and we made pipes out of cans in "emergencies" we'd use the outside of the can as where you put anything with fire, you don't have to turn it inside out to be able to smoke out of it.
Some stoner-engineering could hook up two cans with each other, one is the cup you use for burning the material and the other one the "water-passageway". Obviously not recommended as there is plastic liner on the inside, but in that way you could use the inside :) Basically a bong in two pieces made out of two cans.
