Cheers mate, I ended up gluing it at level with the tank. Just finishing the plumbing now, But so far it's all working very nice, I'll post an update pic when it's done and back in place. (It has hanging lights and other tanks built into the cabinet haha everything is a mess right now)
Thanks, but it's probably just the pic lol a lot of my holes ended up with small chips and they weren't fully straight so I had to go back over them to get the bulkheads to fit, but it's like my first time drilling glass so I'm just happy nothing cracked or exploded :)
I put a small bucket on top of the tank and used airline tubing with a tap to drip water down the glass onto the drill bit, and an airline suction cap to hold it perfectly over the job. Just a towel underneath to soak it up, (had to swap the towel a few times over the 4 holes)
I just used my dewalt cordless drill, (I figured cordless cause it's working with water dripping over the job-and I don't have a corded drill )
Set the torque right down to 1. Start off with the drill speed on 1 aswell, just start on an angle and slowly straighten up till your level then you can increase the speed to 2 and full revs is fine as long as your quite straight and level.(this is with my drill) I think the main key to drilling glass is ZERO pressure, you have to let the drill bit do all the work.
I was thinking about it and apart from how practical the term is to say, "Drilling" is probably a bad word for it tbh, it's more like very course polishing lol same with "cutting glass" It's more like a guided break then an actual cut.
I wanted to make up ply wood guides and clamp them onto the tank so it's perfectly level and the drill bit doesn't walk, I think this would give the neatest holes :)
I think some chips in the last few mm is pretty much inevitable though, maybe the pros come in from the other side for the last few mm? Idk. 4mm is easier and cleaner to drill then 6mm.
1" holes took about 30min each.
cheers