How to break the very bottom off a glass bottle perfectly ?

Question

How to break the very bottom off a glass bottle perfectly ?

Answer 1

I suppose a glass cutter. But why?

Answer 2

Score around the bottom of the bottle, where you want it to break, with a glass cutter, a diamond writing point or a triangular file.

Tie a length of cotton based string (not nylon, it will melt) around the line you have scored.

Pour water into the bottle up to the level of the scored line. Soak the string in methylated spirit, denatured ethanol, methanol or any other flammable alcohol. Stand the bottle upright on a non-flammable surface and light the string. allow the string to finish burning then tap the scored line sharply with something like the edge of a steel ruler. You may need to turn the bottle and strike it again.

With any luck the bottle will split along the scored line due to the thermal stress generated.

WEAR EYE PROTECTION in case the bottle shatters.

TAKE CARE. The edges of the bottle will be very sharp!!

Answer 3

a penny.just shake it.it knocks the bottom off it.

Answer 4

The easiest way is to fill it back up with some water and smack the mouth of it really hard.  The trapped air and soundwaves will have the potential to break the bottom off.  If it works, it will be a very clean cut.

Answer 5

A nail or drill bit.  You put it in and shake the bottle.  If you are lucky the bottom falls off.

Answer 6

I've seen a girl do this.  The bottle should be pretty full (preferably with water, because beer will just foam up like crazy if you don't get it the first time).  Just smack the mouth opening as hard as you can with the palm of your hand, and if you do it just right, the bottom will pop right off.  I couldn't believe it until I saw her do it.