David Billington Inscribed thus:

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.

Agreed ! Diamond Drills on Ebay have a good selection that are
inexpensive.

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Best Regards:
Baron.