Drilling for the first time - in 1/2 inch glass. Help!

[ShrimpBandit]

Just bought a 120g tank and I'm ready to plumb my overflow. I'll need four holes for the drain (1 1/2) and dual return (3/4).

I've read up a bit on drilling glass in general, but I'm curious as to whether I should expect extra difficulty or take extra precautions for glass that's so thick. Maybe buy extra bits? Or just pay the $25/each that my LFS will charge (plus a 3-hour round trip with a 120g fish tank..)?

Compounding challenge is that it's December in northern Wisconsin, so I'll probably have to do the work inside the house.

All advice welcome! Thanks in advance.

 

[DED65]

Myself, I would pay the LFS or have a local glass company come out. Cheap insurance compared to a new tank!

 

[G Santana]

If you have a glass place near you, ask them for a piece of scrap and practice on it.

I have drilled many tiles over the years and recently drilled my first tank. Take your time let the weight of the drill push the bit. Drilling a thicker piece of glass is easier than drilling a thinner pane.

You'll be fine, save the money you otherwise would pay someone unless of course you really don't wish to do it.

Good luck!!!

 

[RobW]

Hopefully its not tempered glass.

 

[George81]

I drilled my tank inside my house. I made a plywood jig the same size as the hole I was drilling. Clamped it to the inside of the tank and a piece of plywood on the outside to prevent chip out. Go slow and a water bottle to keep the bit wet.
dont over tighten the clamps.
just make sure it’s not tempered. Call the tank manufacturer and find out.
Drilling from the inside of the tank makes clean up easy.
drilling glass it not hard.
the jig will Keep your bit in place. I made mine with the number of holes I was gonna drill.

 

[garbled]

I did a practice drill on a spare piece of glass I had lying about, just so I got a feel for it. With the cheap drills, you might want 2, because they wear out fast.

Amusingly, my practice piece was tempered. Got 3/4 of the way thru and it exploded. Not exactly confidence building.

 

[RobW]

I did a practice drill on a spare piece of glass I had lying about, just so I got a feel for it. With the cheap drills, you might want 2, because they wear out fast.

Amusingly, my practice piece was tempered. Got 3/4 of the way thru and it exploded. Not exactly confidence building.

Bet that was interesting!

 

[garbled]

Bet that was interesting!

So it turns out, when it explodes, and you are covered in little glass squares, as is your whole shop, they don't just explode. They keep exploding. So it's like sweeping popcorn, while it's still popping. It was one of the most amusing things I've ever seen.

 

[Philly Reefer]

You'll be fine. Let the drill weight push it down. I used plumber putty to held water around the hole. It took me 40mins to drill just 1 hole...
I kept stopping because I don't want to crack the glass.
If you look at my build thread, I have some pictures when I did it

 

[Kfactor]

Lots of water (garden hose ) and go slow let the bit do the work

 

[Kfactor]

I find Constant water flow is better keeps it cool

 

[ShrimpBandit]

Myself, I would pay the LFS or have a local glass company come out. Cheap insurance compared to a new tank!

I'll check prices for the glass place in town. The LFS is soooo faaaaar...

Hopefully its not tempered glass.

Nope, definitely not!

I drilled my tank inside my house. I made a plywood jig the same size as the hole I was drilling. Clamped it to the inside of the tank and a piece of plywood on the outside to prevent chip out. Go slow and a water bottle to keep the bit wet.
dont over tighten the clamps.
just make sure it’s not tempered. Call the tank manufacturer and find out.
Drilling from the inside of the tank makes clean up easy.
drilling glass it not hard.
the jig will Keep your bit in place. I made mine with the number of holes I was gonna drill.

Thanks for this. My hubby, the carpenter, had suggested something similar and was glad to hear that it might be a good solution.

I did a practice drill on a spare piece of glass I had lying about, just so I got a feel for it. With the cheap drills, you might want 2, because they wear out fast.

Amusingly, my practice piece was tempered. Got 3/4 of the way thru and it exploded. Not exactly confidence building.

Yeah, not sure I would have made another attempt. Hope you're still in one piece!

Thanks, everyone, for the advice and encouragement. Sounds like the thicker glass doesn't really call for anything more than extra patience and maybe a spare bit. I'll keep my fingers crossed and update the build thread when I'm done.

 

[theMeat]

Go slow, use water to keep it cool. Laying it down so you can work flat helps, a jig helps too. Don’t force, let bit do it’s thing

 

[DanConnor]

I used a sheet of a pink foam insulation for a jig, around an inch thick. Taped under that was another layer with a much bigger hole. Inside that bigger hole was a ring of playdough to hold in the water. Sounds complicated but I drilled about a dozen holed in 1/4 inch glass in under an hour.

 

[Pistondog]

Put a towel down to catch the glass slug, ease off when you're about to drill thru to minimize chipping on inside of hole.
Slow and wet.

 

[Peace River]

One idea that I have always found helpful as I have drilled tanks is to think about the process as "grinding" a hole in the glass instead of "cutting" a hole.

 

[polyppal]

It’s not as scary as it seems after you’ve drilled a hole or two. IME the thicker glass is easier to drill than a thin panel, since the thin is more brittle. Like someone else suggested, practice on a scrap piece of glass or old tank to build up some confidence.

A diamond hole saw bit actually sands/grinds its way through the glass little at a time, it’s pretty gentle if you take the proper precautions and take your time. The most important thing is to ensure 100% that the panel you are drilling is not tempered!

I highly recommend using the little wheel guides or template that holds the bit in place as your getting started. If not it will likely skip around on the surface a bit at first which would make it hard to make holes that are level with eachother. I also put masking tape on the area where the exit hole would be, which prevents little corners chipping as the bit is coming through the other end.

 

[lelandmarine]

YouTube has some nice videos that give some good tips, as well as all of the above from fellow reefers