Originally Posted by gcgradhttp:///forum/thread/383047/to-drill-or-not-to-drill/40#post_3357106
Thanks Joe, not quite sure what I'm looking at Al. Please explain!
This is a dam that is clamped to the inside of the tank, there is a guide inside the jig, same diameter as the holesaw to prevent the holesaw from dancing along the glass. The dam jig is filled with water to cool the holesaw as it is cutting.
Thats pretty clever. I just got some baffles from a glass store. They cut the first ones wrong so I had them cut them all over again. So I have 4 big pieces of glass sitting around that I don't know what to do with. I guess I could practice drilling those and if it works I could clamp it flush up against the tank and drill it to keep the hole saw from sliding around. This might give me some confidence for drilling the real thing. Although the glass pieces are 10"x11 3/4" and 13"x11 3/4" so not sure how they will hold up, and I'm not sure whether they are tempered. Guess I can just give it a try, nothing to lose considering I don't know what I would do with those pieces anyway.
Al always comes up with some good ideas. I like that jig. You could also do something similiar with a piece of wood and drill a 1-3/4 hole through that and clamp it to your tank and use it as a guide as well.
The extra baffles I would keep handy, you never know when you may do another build. If you ever decide to pick up some of those diamond coated rotary bits for the dremel then you can grind down the excess width yourself and make them fit in another tank. Super easy.