How safe is it to drill untempered aquarium?

[RIP]

Hi everyone,

So actually it's a terrarium, but roughly the same thing, it's a glass tank with the kids pet gecko and forest environment. It's will have a ceramic heater, a water feature and has a 10l pond in the corner that you can't see. Those need some wires and tubes routed to them. This time instead of running wires and tubes up and over the back I want to drill a 20mm hole in the side.

I've checked the glass with a pair of polarising filters and it appears untempered.

So the plan is to cut a plywood template to guide the drill bit and stick it to the glass. Regularly dip the diamond bit in water. And just let the drill bit scratch it's way through the glass. This should be safe I hope.

Would you share any tips or experiences?

 

[Brad93]

like cutting tile i should think, plywood both sides of glass to be safe with some lightweight clamps

 

[Domdom]

OK, I have done 2 of mine, one with 2 holes in the back. I used a block of 5x2 to guide the cutter and went slowly. Had a hose dribbling water constantly to keep it cool and lubricated.

What I also did was cut 2 squares of 3/4" ply about a foot square to go inside the tank and then a piece of 3x2 to go between them. A support from underneath if you prefer. I also used a mains drill as it's easier to keep the speed constant.

The biggest risk is when it breaks through. I could feel when this was about to happen and reduced the pressure on the drill so it was at a point of scuffing its way through really gently. Takes a good 10 minutes per hole.

I have done many previously and will tell you that 10% will crack the tank. Thicker glass on large tanks are the least risky, but the thin stuff in small breeding tanks is more like 1 in 4 breaking.

 

[voipio]

Drilling glass underwater reduces the risk of breakage, because the water will absorb the shockwaves that are generated as the drill bit bites off the glass, chunk by chunk, rather than sending all the shockwave energy through the glass. This was most vividly demonstrated as a kid, by knocking holes in the sides of glass milk bottles, using a hammer and nail. The holes weren't pretty, but the bottles remained intact.

 

[CompoSimmonite]

Could it be worth taking tank to a glazier and getting them to drill the hole rather than spending money on the drill bit ?

 

[Erie Fred]

You could use a hole in some steel as a mask, and then sandblast it.

 

[Hopefuldave]

Drilling glass underwater reduces the risk of breakage, because the water will absorb the shockwaves that are generated as the drill bit bites off the glass, chunk by chunk, rather than sending all the shockwave energy through the glass. This was most vividly demonstrated as a kid, by knocking holes in the sides of glass milk bottles, using a hammer and nail. The holes weren't pretty, but the bottles remained intact.

Water really works, I've cut glass under water with a pair of scissors...

 

[daleyd]

@Misterg would be my go to on this subject,

 

[mike os]

Easy peasy... I've done hundreds

Ply template cut with the hole saw to hold the bit in place

High speed, very gentle pressure... literally just resting on the face, and loads of water ... flooding it

If it's dry it will either heat or bind and crack

 

[Misterg]

@Misterg would be my go to on this subject,

Very flattering, @daleyd

I think previous replies have got it covered, though: Constant stream of water, slow cutting speed & take it steady. If you can put something behind it (sheet of ply??) to support the glass as the cutter breaks through, it'll improve the chances of getting a neat hole.

 

[Dee J]

Water really works, I've cut glass under water with a pair of scissors...

That's something that was always quoted in old encyclopedias....but scissors bend the material as they cut. What was your experience?

 

[daleyd]

Very flattering, @daleyd

I think previous replies have got it covered, though: Constant stream of water, slow cutting speed & take it steady. If you can put something behind it (sheet of ply??) to support the glass as the cutter breaks through, it'll improve the chances of getting a neat hole.

If you couldn’t answer a question about glass we are all in trouble

 

[RIP]

Very flattering, @daleyd

I think previous replies have got it covered, though: Constant stream of water, slow cutting speed & take it steady. If you can put something behind it (sheet of ply??) to support the glass as the cutter breaks through, it'll improve the chances of getting a neat hole.

Reassuring the tank has been set up and is too heavy to move so I'll need to devise some way to catch the water, maybe a foil sump stuck under the hole, and a 12v pump pouring water over the diamond hole saw.

 

[RIP]

Easy peasy... I've done hundreds

Ply template cut with the hole saw to hold the bit in place

High speed, very gentle pressure... literally just resting on the face, and loads of water ... flooding it

If it's dry it will either heat or bind and crack

What's your success rate like?

 

[creepy]

I tend to use the bits that are designed to go in an angle grinder rather than a drill now, much higher RPM, not used on glass (but have one to do some time - back burner project) but tiles are so much easer with the high RPM. Mains drill is recommended for the type you posted for the same reason. Watching with interest for my round2it.

 

[Bornfree]

This is what you need, and a medium sized hammer.

 

[mike os]

What's your success rate like?

99%. I used to drill additional holes in big installed aquaria as well as new, and build fish sheds/ shop tank systems as a sideline

The key is controlling water and once you start to break through take it extra careful

 

[mike os]

Get a piece of scrap and drill some holes ... you'll soon pick it up

 

[RIP]

And are you folks using regular generic diamond hole saws?

 

[mike os]

Yep, and preferably used a couple of times before anything important