BEER BOTTLE DRINKING GLASSES

CONCEPT:
Cut, sand, recycle empty beer bottles with unique and interesting labels into a set of cool drinking glasses.

PLAN:
Take a few empty beer bottles. Wash them out. Wrap a cotton string around the part of the bottle you want to cut, and tie a knot. Slide the string off of the bottle and soak it in lighter fluid or nail polish remover. Slide the string back onto the bottle and light it. Turn the bottle so that the flames move evenly. After a few seconds, dunk the bottle in ice water, and it should crack, separating the top and bottom. Sand the raw edge down to a smooth finish, and clear coat the outside of the bottle with a protective coating to prevent damage to the label during washing. (hand wash only)

STATUS:
This is a lot harder than it sounds. The bottles keep breaking extremely unevenly.

I keep trying different variables to see what the problem is, turning the bottle at different speeds and angles, using different amounts of string, different temperatures of water. I have narrowed it down, I think, to braiding the string, turning the bottle slowly, and using the coldest possible water, with lots of ice. I may need to see if there is a difference between using lighter fluid and nail polish remover. Perhaps one burns hotter than the other.