"mm" wrote in message
...
On Fri, 4 May 2007 12:08:21 -0700, "charlie"
wrote:


Method 3:
Get a dremel tool with a thick grinding wheel, and prop it against
the glass, running, and go read a book.

without coolant, nfw this will work

For coolant, could one just fill the bottle with water. Or does the
water have to be closer to the wheel?

you're cooling the tool and the glass you're grinding. temperature
differentials in different places in glass cause cracking. the water on the
inside won't cool the outside of the bottle except through convection, and
glass is a good insulator and a (relatively) poor conductor of heat. that's
why you have to carefully anneal glass when cooling it.

regards,
charlie
http://glassartists.org/chaniarts