Drilling a Hole in Glass

Plain old plate glass can be drilled like masonry with water cooling and abrasive or a carbide bit. If it is tempered glass it will break. Better stick with a siphon for draining the tank.

They sell glass bits everywhere...It takes a long time to drill the hole, you basically just wear a hole in the glass rather than like drilling wood or metal....so don't be in a hurry, and don't force it...

http://www.amazon.com/Hitachi-728028-8-Inch-Diamond-Core/dp/B000NK7DC0

My local home improvement stores sell bits for drilling ceramic tile. They are basically a small hole saw with small diamond chips bonded to the end of the bit. I have had very good luck drilling ceramic tile with them. I would think that if you go slowly and gently (probably using a drill press) and keep the hole (grind spot) flooded with water then you would have your best chance of cutting a hole without cracking the glass.

I have never used these bits on glass so don't put too much faith in my suggestion.

I tend to agree with LG Dave. If it's tempered it's likely to shatter.

Why don't you drill your drain hole in the bottom of the aquarium, (the very bottom, not the glass), and just set it up on small blocks to keep from crimping the drain hose?

A small brass drain valve for a compressor would do it.

Good advice, as usual.

Thanks.

Very interesting experience! As I cant stand figures ending in "0" I´ll give you a GA, for you to reach 201 Good answers in your counter!

Or if the tank is too heavy/cumbersome to move: get one of those mobile units that sand blasts/etches you number plate (registration plate) on your car windows to quote to come and do it.

Does Laser work on glass? If it does, find a job shop with a laser machine.

hole will be uniform, and very good finish.

Laser may work, but tempered glass will not resist to temperature gradient of the surroundings of the hole.

Excellent. Yes, it's been a while, not sure where I got the rod notion but tubing is the perfect technique. Thanks!

I agree.

I have been doing this for decades. I use this even to drill drainage holes in ceramic ware which I use for bonsai.

A short length of wooden dowel will do a nice job in a slurry dam too... The flat end-grain holds the grit better than the steel rod! IMHO

Nope, too simple! You cannot come with such a simple and workable solution?!?

Post 17 is actually a very good solution, it has been used for years.

The grit is picked up by the soft copper which wears as it does its job,[ how long is a piece of tube?] and the slurry keeps the glass from temperature shock. You should also always use diamond grinding with water for the same reason , diamond powder is also available for the same purpose.

It is always a good idea to prepare the exit side of the hole[ if possible] by pre drilling a short way into the surface to avoid breakout splintering which can lead to stress cracking, otherwise both edges of the hole should have the edges of the hole broken with a solid round nose copper rod and abrasive to avoid future stress cracking.

Beware tempered glass.

Tempered glass has a "mark" on one of the edges, for identification--Non-tempered glass, and often tempered glass can be drilled using high speed tapered diamond bits, using kerosene as a carrier for debris, and also as a lubricant--I have seen many glass drillers, on jobsites, using these techniques on huge pieces of custom glass, and also mirrors, that need to be "friction supported"--Try a sample piece first--Better to learn from failure, than to learn from a lucky break.. Pun intended..

If you find you cannot drill it, simply siphon the water out.You could use the siphon hose to help remove debris from bottom as well, whereas a drain hole will remove only debris close to it.

In these parts glazers use diamond crusted abrasive hole saws. I have witnessed the process and it is performed reliably with basic tools and scant attention to any potential technical complication. Normally by the time you've voiced any concerns the job is finished.

Any hole in a fish tank would worry me. It introduces a new point of potential failure and a drain complicates the design of the tank stand/cabinet. Tank failures/leakages result in high collateral damage. Something you don't want to increase your risk exposure to. Trust me on that score. Of course, if you really want to drill the glass then go ahead it is neither impossible or difficult.

I have owned a number of fish tanks over the years and have always siphoned them empty.

A little off topic here...Another advantage of siphoning is it lets you effectively vacuum clean the gravel. Easier to watch this than to explain it. The suction plenum could be easily fabricated from cr4p in your shed. The clear ones sold in aquarium supply shops are nice to watch while they work and are uber cheap too.

So, what you gonna do?

Glass is cut, rather than drilled. Score around the circle that you want to cut out, or drill a small hole and use an abrasive to widen it.

Ask yourself "why doesn't every Aquarium have such a hole?".

Simply because:-

a) too much breakage when drilling a

and

b) weakens the glass considerably and probably allows the glass to break when filling and you get 10 gallons of water in the living room......

A pump or a siphon would do it in a far safer manner.

But if you are still set on doing it, the Google "how to drill through glass", you will even get YouTube videos offered.....

i am considering epoxing two large washers on both sides of the hole location.

the reason for the drain is because ammonia seems to settle to the bottom of the tank. i'm hoping that i will only have to drain a few gallons of water to clean the gravel filter and still leave the microbes active. i think that method won't stress the fish as much.

Take the drill off hammer first . then take the tank to a specialized glass Co and ask them to drill it, If the glass is old the chances of it breaking will be increased, If you are intent on drilling it yourself you need to form a dam around the drill area a couple of inches all round into which you put white spirit, you must use a dedicated glass drill ( they're shaped like a spade on a pack of cards ) and you must drill as slowly as possible. I still say take it to a professional.

Bazzer

Let's be practical about this.

The goal here appeares to be to clean the fish tank.

OK, Drilling a hole in glass has been a great and very informative discussion..... Thanks to all....... Great advice.

Here is my advice.... Go to your local Automotive store and get a general purpose hand pump. They are used for draining oil from a crank case, gas from a tank, antifreeze from radiators. Most have siphoning feature. So once you get flow it will drain the tank with out further pumping. These pumps are about $15 --$20.

Please.. If siphoning the water out watch the water level or take the fish out of the tank. They like water.

Now why did I not think of that.

Plenty of good advice. But, I go with #27.

Glass comes in 3 flavors:

1,. Untempered. At least not intentionally tempered, as it takes too long a time to cool the sheet glass to be without internal tensions entirely.

2,. Tempered. It is designed to have high tension in the outside layers, by heat treating the item after fabrication. The very purpose of it is to shatter into roundish blobs on impact. The purpose is not to have bad cuts after a car accident.

3,. Safety glass. US car windshield. Layered glass / plastic sandwich. Will crack, but won't shatter, no matter what.

#1 and #3 can be handled fine after fabrication. You are asking for trouble by handling, like drilling #2. It will explode, or crumble into your face.

Viewing them in polarized light will show you the tension in the glass. You decide.

I have used water jet cutting to drill holes into glass. It works very well on non tempered glass.

On Tempered glass drilling a hole is a bad thing. I had a try at it just as well and while it seemed to have worked initially, the samples cracked after a while due to slow crack formation.

One more advantage with water jet cutting is that you can freely chose the shape of your hole (might not be of any use to you in this case).

you casually find a business with a water jet cutter in a industrial park.

Plastic tubing and sucking to make a syphon works fine - just remember to move mouth as the gunky water comes down the tube. The fish might appreciate a heads up too.

Easy. No drilling. I used to build cloud chambers out of gallon glass jugs. Cut top and bottom off using glass cutter and needed 1-2" hole in side for electron injection. Now build a donut of putty with hole size needed. Place on horizontal and dribble a puddle of hydroflouric acid into putty donut. Stir every so often with toothpick. Takes about 6 hrs or less if you change acid pool every so often. Very intricate shapes and precision edges can be done with time and patience. A string soaked in acid can be used as a loop cutter. Cardboard tube can be used as drill as can wooden dowels. Think outside the box and have fun. ps Safety and tempered cut just as easy. Need to come in from both sides on safety glass. We did this in high school science fair. Paul

Youtube

www.youtube.com/watch?v=r9x9vV2cXRY

Drilling a hole in a glass aquarium

Just watched the film on U Tube answers all the questions, job done.

Bazzer

My father used to drill plain glass with a piece of thick walled copper tube the size he wanted and grinding paste. The drill speed was slow and pressure light.

My advice is... Don't use the Impact setting!

I would stay with siphoning the tank clean but if you realy want to make the drain hole In the past I have used a dremel with a bit that has a diamond encrusted tip they come in various kits for engravers it is slow but it is easy done. But as others have said practice on another piece of glass first.

...forget drilling , too risky and unecessary

...forget any kind of pump too expensive and unecessary

...forget sucking hoses , too tiring ( and tastes bad when mistakes occur !! ) and unecessary

...get yourself a length of hose coil it up sumerge it in the tank , fill it with water , put your thumb over one end , bring it out of the tank , drop it below water level , ...hey presto, siphonage !!

...need more suction raise the hose where it emerges from tank before it drops to drain

...use it to thoroughly clean dirt and deposits

Second to last comment is incorrect. No matter how high you raise it the fall is from the tank. What goes up, must come down.

I drilled a hole in glass with a dremel tool and diamond grinding bit. Slow speeds and a little at a time so heat doesn't build up. If you push it there will be cracks. I tested my method on an old piece of the same glass as I was replacing the old glass.

We have very specailized drill presses that drill 1/2 from bottom side and finish 1/2 depth from top side they have hollow core diamond imgregnated bits that constantly flood from center of bits.This produces clean holes without the exit explosion of chips.We also watercut holes however our machine has a specail feature most waterjet systems do not have and that is the ability to peirce at a very low pressure (8,000 psi)in a tiny spiral motion and then ramp up to cut pressure (50,000 psi).If you try to peirce in high pressure it will break.

It is possile to drill from a single side however the odds are you will have some very tiny cracks and chips that over time under load will fail.

Look at what could be damaged if that occurs if you are on a second floor condo look at your neighbors things that you might have to pay for.

If you must have a hole in the bottom then order a tempered glass with the hole allready fabricated.Anyone who thinks you can drill into tempered glass is wrong I don't care what you have read or if you think you have done it in the past it is not possible.

All in all it is not a good idea.I strongly advise against it.

Don't try to center punch the spot you want to drill.