How many drill bits should I use?

[Kyle918]

I am planning to drill my tank this weekend coming and I have 2 drill bits on the way, one for the bean animal overflow (3 holes) and one for the return (2 holes). The glass is half an inch thick. I was suggested today that I use a new bit for each hole but I wanted to ask here to get further opinions first.

[Reefmedic79]

With a quality bit, I've always gotten at least 4-5 holes. Just make sure you go slow and lubricate well.

Is this for your 75g rimless? If it was custom made make sure it can be drilled.

[Kyle918]

Originally Posted by Reefmedic79

With a quality bit, I've always gotten at least 4-5 holes. Just make sure you go slow and lubricate well.

Is this for your 75g rimless? If it was custom made make sure it can be drilled.

That is what I thought. I ordered the bits and bulkheads from BRS. I plan to use plenty of water and yes, the tank is not tempered on the rear glass. The other sides and bottom are tempered though.

[James77]

I bought a cheap-o bit from either gla ssholes or BRS for about $15 for the 1" bulkheads. I drilled maybe 9-12 holes with it before it started slowing down.

As reefmedic said, go slow and lubricate with water and let the bit do the work.

[James77]

Another pointer would be have a template or piece of wood or even cardboard to use as a guide for starting. Otherwise, you will have that bit dancing around even if you try to angle it to start biting. Use plumbers putty to hold water. Have a towel underneath the hole to catch the center cut part, or at least be ready to have a hearty attack when it drops . I have not perfected the breakthrough of the hole, I always get some mione chipping. Not a big deal at all, as the bulkheads more than cover it. But consider reading up on techniques for that.

[triggreef]

Let the bit do the work is key. But also make sure you have a drill with a clutch. You rather the drill stops turning if it snags so that the glass doesn't shatter.

[triggreef]

Also for the rear of the hole chipping I used masking tape and it seemed to help.

[James77]

Originally Posted by triggreef

Also for the rear of the hole chipping I used masking tape and it seemed to help.

Yeah, I have done tape and I still get some very minor chipping...maybe it is just me being a perfectionist? Or I am not cutting through evenly. I have also thought of cutting through 2/3, then drilling from the other side...you would do that for wood to avoiding splintering. By no means OP should you follw that advice, Im just thinking out loud

[Reefmedic79]

Not to get completely off topic, but I found the best way to drill a hole is using a drill press. It takes a little thinking to figure out how to get a whole tank under the press though.

[Kyle918]

Excellent. I'm glad I don't need to buy more bits. I have read that some minor chipping is possible but I do want as clean of a hole as possible so I will look into ways to prevent that. One suggestion I read a while back was to lift up on the drill so it is less weight when you are near the end of the drilling.

@reefmedic - I would use a drill press but I don't think I want to go through all the trouble for about a 30 minute job. I will make sure the drill has a clutch and will probably use a piece of cardboard to line it up initially.