tempered glass

[spookey]

if u dont know if your tank is temp glass u can try this http://www.alumaxbath.com/tech/tgp.htm



chris

[spookey]

and here is a site that will help u with the speed on drilling tanks


http://www.diamond-drill-bit-and-tool.com/Diamond-Drill/Default.htm?DD1.htm

chris

[cweber]

Very interesting article. Thanks for sharing.