Drilling a glass tank

!!WARNING YOU CAN CRACK OR DESTROY YOUR TANK BY ATTEMPTING TO DRILL IT!! I hold No liability if you screw your tank up
!!! YOU CAN NOT DRILL A TEMPERRED GLASS TANK!!(many 55 gal sides are tempered)
What you need:
Drill
Glass cutting drill bit
Tape
Bucket (2 if possible)
Garden hose with water supply

First off mark your holes. I have been told you must be at least the size of the hole away from the edge of the glass. Here we used a sharpie to mark my tank:

Put tape on the back side of the hole, this prevents the glass from falling into the tank possibly breaking the glass, however at the same time you have to be careful that the drill bit doesn't go through the tape:

The 75 gallon was big enough that we were able to put a 5 gal bucket under the hole, in case the tape fails or we drilled through it. If you can't get something like that to catch the drilled glass disk, you can alway but a folded towel directly under it to catch it.

Get your drill, drill bit, and water hose.


I put the chord and plug of the drill into a bucket to prevent the plug from getting wet and lowering my chances of electrocuting myself. As an added bonus, I made sure that the drill was plugged into a GFCI plug, **which is highly recommended**.

Start drilling:
Throughout drilling make sure there is enough water to rinse off all the glass dust, this prevents the glass dust from entering your lungs and it keeps the diamond tipped drill bit cool and sharp, we regulated the water flow to about a half gallon a minute. Also do not apply too much pressure to the bit! Allow the drill bit to do its job. Pay particular attention when you get close to the end. The more you press down the higher the risk of chipping the inside glass or even worse breaking the glass.

Line up the mark with the edge of the bit and score the glass. VERY SLOW SPEEDS!
Hint, it will be easier to score on a portion of the bit surface (i.e. hold the drill at an angle so only part of the bit touches)
Square the bit and once you have a good groove you can speed it up a bit.
Click on the picture below to watch the video:

As mentioned, when you near the end of the hole make sure you are barely putting pressure on the bit. When it’s done it should look like this:

Also, you can always go slower, it will just take longer. My 75 with 3/8inch glass took about 15 min for the first hole then maybe 7 there after. the 15 min hole looked the cleanest, but took forever. The thinner the glass, the more careful you need to be about not applying too much pressure. from what I have read, those small tanks are really prone to crack.

Nice write up. Good job

Good write up DW. Can't wait to see the video.

Question: how long do those drill bit last?

3x what they say apparently.

I'm still scared to attempt drilling. Maybe once I'm rich I can afford a new tank if I break the first one or have professionally done.

DW was the same way when he drilled his first hole, I assure you it isn't as hard as it looks.

your tank is a 60 gallon which means it has thicker glass. thicker glass is easier to drill.

Hey dwolson2,

Why so many holes?

BTW, That's a cool shirt.

i think he is doing a bean animal style overflow its a coast to coast meanning its going all the way accross the top of the tank. its supposed to be super quiet. look it up i think he has his own website for it.

Check it out here I have done a 75 this way as well and it is super quiet, DW also had the same set up on his 30 and you couldn't here any water flow. Definitely a tried and true design.


BTW that's me in the shirt, the model didn't show for the photo shoot, so I was the next best thing

thats good to here my dad is going to do this same thing on his nano the drill bits are in the mail.

its not a true C2C, only about 18 inches. I am going to have a bean animal with dual returns. It will be dead silent. I really liked it, I actually plugged up my siphon with a snail,which I didn't find till I took it apart, and it handled it like a champ. no problems at all! I also read that if I take a round over bit to my 0verflow, it will make it silent too!

nice so you mean like make the accrilic on the overflow where the water goes over round? hmmm. intresting

yea, read it in a nano forum while looking up if ABS plastic is good for overflows(which it is, its also about 2/3 the cost of black acrylic)

hmm. my dad is doing a clear glass overflow it might be a little hard to do that to glass but im sure there is a way

Does it share the same characteristics on bonding 2 pieces of acrylic together? I wonder if you can use weldon in that fashion for ABS.

yea, I use crysties blue, I called the manufacturer of my cement at home

Cement?? what? are we talking about the same thing?

solvent. that's the "correct" term for it, but we used to call it PVC cement

So you have to use a cement to bond ABS together? A lot like you would glue PVC piping together?

exactly like that. I called the company, like i said

We're talking about 2 different things here. I was asking if you bond 2 pieces of ABS together like you bond acrylic together and apparently it's 2 totally different processes.

its like pvc

video added

also to add to the ABS plastic part of this thread, chrysties blue will work, but you need to gob it on and hold it for a while. Its a real PITA. afterwards I would hit it up with silicone just to make sure it stays water tight(which I did, I was already in there attaching it to the glass)

like the video.

I like the part when ur all like oh hello

I thought the same thing. what a great place to stop the recording.