Quote Originally Posted by hreskofreight4
why would boiling glass be just asking to break a piece...?
Boiling glass is just asking to break your piece because it causes the molecules of the glass to expand and contract more rapidly then they normally would.

this causes the glass to become more brittle or can out right make it shatter if you cool it down TOO fast.

Need an example? pull a light bulb outta a socket thats been on for a while (be sure to use a cloth or something so you dont burn yourself) then run some cold water over it and watch it shatter.