[Hallicrafters] drilling glass

[Mark Shaum]

One tip I recall when I last had to drill about a 1/4 inch hole through 
a fairly thin glass sheet was to use putty to form a little ring around 
my drilling center point.  Then you can fill your little putty "volcano" 
with lubricant/coolant and drill with a sharp, carbide bit at slow speed 
and slow feed.  This helps keep the lubricant and glass particles 
flowing away from the hole as it is drilled without having to drip 
lubricant on the glass on a continuous basis.  Clean out the hole as 
drilling progresses, continue as in the beginning.  I must admit I only 
did this twice, once to test the technique and once to get the hole I 
needed through a glass window pane, but it worked fine both times.

73!  Mark, K9TR