Drilling a hole in a glass jar

[shirley-il]

I have a jar that I want to put a 5 watt bulb in. I would like to run the electric cord through a hole in the back of the jar. What kind of drill bit do I use and what is the process of drilling in glass.

[JLMCDANIEL]

shirley-il,
It's a messy job. You have to grind a hole not drill it. You will need a diamond glass bit of the appropriate size, about ¼", and it is best to use a drill press. Place the bit in the drill press and run at slow speed with very little pressure. To much pressure and you will shatter the glass. You will need to keep a cooling medium, water will do, flowing on the spot you are grinding. Starting and stopping would also be a good idea. The diamond bits are usually less than $20. Patience is the key and you might want to try a couple of test jars first. wear goggles or face shield and heavy gloves. Her's a site with bits and some instructions http://www.diamond-drill-bit-and-too...-Drill-Bit.htm
Jack

By the way, if you drill through the bottom, I usually just fill the jar about ¼ full of water and drill down through the inside, Have a bucket handy.