Quote Originally Posted by rspears View Post
Yeah, the problem is that if emptying the bottle immediately precedes the build process the rate of breaking bottles while trying to cut the bottoms off cleanly increases dramatically.
A wee trick for cutting the bottoms off bottles cleanly: an inch of oil in the bottom of the bottle, heat a steel rebar, dip it into the oil, repeat until the oil gets hot. Eventually it will break cleanly at the top level of the oil.

Perfect for making glass fuel bowls for obsolete machinery.

(How did I learn this trick? Don't ask! )