<a href=showthread.php?s=&postid=9326026#post9326026 target=_blank>Originally posted</a> by JustOneMoreTank
Hey Bleedingthought!
Well today my fish club and I drilled three holes in two tanks. Both tanks were top/open side up and I drilled them on the back glass. Our reef club will have a video posted on the website hopefully sometime soon. Ohh great... now everyone gets to see me sweat it out in front of a crowd drilling a pair of tanks. 
I find it just as easy to drill the tank laying on its side or standing upright. Although I will admit that it does help to have someone watching from the side to tell you if you are working directly in or if you have the drill angled up or down. It is difficult to tell sometimes when you are holding the drill exactly how perpendicular you are to the tank surface.
We will post a link so that people can see the video tutorial on tank drilling.
So, I'm hoping to put an order in tonight for those hole saws. Buying through e bay. Company is THK DIAMOND TOOLS the username still the same - lau***.
I was going to get the hole saws for a 1", 1.5", and 2" bulkheads (Schedule 80, which are heavyduty sized bulkheads). And here are the size translations (mm are rounded) for these:
1" bulkhead = 1.875" hole = 47.63mm hole
1.5" bulkhead = 2.625" hole = 66.68mm hole
2" bulkhead = 3.250" hole = 82.55mm hole
Now, they don't have any of those exact sizes available. The closest are: 48mm, 65mm, 80mm and 85mm. The 48mm and 65mm are pretty close to what is needed for 1" and 1.5" bulkheads. But for the 2" bulkhead, the 80mm is about 3/32" too small and the 85mm is about 3/32" too big. Which brings me to my question, would it be better to have the smaller one and bore the hole out with a dremel or would the bigger one work?
Thanks!
