[LoneWolf345]

I need to drill a hole in the bottom of a 2.5 gallon glass tank. I'm looking for advice on doing this. Since the tank is so small I'm pretty sure that the bottom is not tempered glass.

[Samper]

You will need a diamond bit, some putty of some sort, water to lubricate and cool and a drill you can set the speed on. It really doesn't take that long but you do have to make sure it's not tempered or you will destroy it. Just build a dam with the putty and make it surround the entire hole and about 1" wider than the hole to be drilled. Fill this with water...when drilling you may have to do this a few times especially towards the end if you happen to slant the drill on accident. You start the drill on a pretty low setting....too low and it kicks around and too high....just feels like it's too fast. I don't know how else to explain it. Put the bit against the glass at an angle...this is the toughest part to me. You want the bit to bite in just enough at that slant to make a half moon but it does tend to jump a few times before it bites in. Once you get this half moon edge, keep the drill running and slowly straighten it up so that your flush against the glass. You don't really want to put pressure on it at this point. Hold the drill steady and let the bit do the work. If you put pressure on it when you're almost through, you may end up chipping around the hole. It's so thin that it breaks instead of gets cut and that can make a bulkhead hard to seal. I hope this helps.

[Samper]

Here is a little more in depth explanation by Scubadude

Drilling glass tanks TOTW 1-24-05

[LoneWolf345]

Originally Posted by Samper

I hope this helps.

That helps so much. I'm sure I would have messed things up.

[Ratpack]

Check with LFS and see what they charge or a glass comany unless you already have the hole saw. I was going to drill my own tank until I priced the hole saw @ about $35+. My LFS drills tanks for $25 per hole. So it is cheaper for me to let them do it and they are also experienced. Just a thought.

[Samper]

Personally I'd rather get the bits to drill my own because a good bit will last for a while. I've used mine 12 times and it's still working fine. You'll have to ask KGeorge what kind it is though because he originally bought it.

[LoneWolf345]

Ya for $10 more I get to keep the bit, I think I'll go with that. I would be nice to what what bit works the best (brand, model, ect.)

[Ratpack]

I actually found some bits on Ebay now that are $10 shipped. They are from asia, but for that price, if they only last to drill the few holes I need, then it will be worth it.

My other post was just in case you only needed one hole which is what I was looking at then. Now I need about 6-8 holes so it will definitely be cheaper to buy the bit. Unless I crack the glass.