Karl Townsend wrote:
Milady needs me for my shop skills. Don't happen that often.

She has old canning jars. The type with a glass lid and a little wire
arrangement to pull the glass lid tight. She wants to put small lights
inside and needs a hole drilled. I haven't measured up for sure, but
I'm thinking this stuff is 1/8 NPT size.

OK, how do I drill very old glass? I get several points off for every
one I break.

Karl

The old way would be to use some copper or brass tube with an OD the
size of the hole you want. Make a dam round the hole with plasticene and
add some abrasive like valve grinding paste and a bit of water or oil,
Hold the tube in a drill press running at a slow speed and repeatadly
apply pressure and lift. The abrasive imbeds in the softer tube material
like a lap and grinds through the glass.

The new way would be to use a diamond hole saw but still have the dam to
retain water to keep the glass cool. You can probably buy them on eBay
for a few dollars in the size you want.