From: "Bob May" 
To: "atmlist" 
Reply-To: "Bob May" 


The scoring and breaking of the glass will work but you may find that the
cracks don't propagate straight down. Better would be to use a diamond saw
if you want rectangular blocks - the saws cut through the glass almost like
wood and you do need to use plenty of water - or, if you want round or oval
pieces directly, do the trepanning method.  That is merely making up a
piece of pipe or other round cutter like that and start feeding it into the
glass with some grit (I tend to use 180 grit for my trepanning) while the
cutter turns around.  The trepanning can take some time but it is a
somewhat low maintenence process.  When the pressure can be applied well,
you can quickly obtain cutting speeds of about 2 inches or more an hour. 
If there is a concrete hole cutter of the right diameter that you want, you
can also use one of those to cut the plug.  In any case, use plenty of
water to keep washing the glass swarf away. Bob May
http://nav.to/bobmay
bobmay{at}nethere.com
NEW! http://bobmay.astronomy.net

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