Quote Originally Posted by Goodman3eb
I thought it was the Mohs hardness scale?
http://geology.about.com/library/bl/blmohsscale.htm

Anyway, I've given it quite a few tries, even with a good drillpress and a diamond-tipped bit, but always end up breaking the glass one way or another. If you want to use a standard 9mm slide and rubber gasket, you'll need a 1/2" hole-- thus a 1/2" drillbit, which cost me around $13.

Here's the problem I have-- the drillbit flares out such that it become really quite wide before it gets all the way through the glass, such that when it breaks through the glass all the way, it punches through with a bit of force--that is to say, I was putting force on it so it makes SOME progress while grinding away all that glass-- and breaks the glass. Even when I do manage to get through the glass, the bit tends to rattle so much against the hole-- it's hard to hold the vase/bottle still while drilling-- that I end up cracking it anyway.

Here's something I've always wanted to try, that I think might help out somewhat: melt some wax-- you can get canning wax, or paraffin, at any craft store-- and pour it into your bottle, just to the level where you want to drill. Once it dries, you have a relatively hard, stiff surface to drill into, supporting the glass from underneath and facilitating easy drilling with no breakage. Once you're done drilling, submerge the vase in boiling water; the wax will melt, and hopefully flow out of the newly drilled hole, leaving you with a brand new bong!

Again, I don't know if that'd work, but it sounds feasible.

On my one success, I ended up with a fantastic little mini-bong that I love and all my friends love too. I think the reason that one succeeded was that once I got through the glass, I was able to hold the vase steady enough to keep going all the way with it.

Anyone else have a real-life success with this?
do you have water at hand when your drilling? if you put a few drops for every minute or so of drilling you do, it makes it less likely to break...