How to Drill your glass

Now we need to use a cooling lubricant or we will ruin our diamond drill bit with only one hole and we might even crack the glass. I am using a cooling lubricant specially formulated for drilling glass. It comes by the gallon and you mix it something like 20 to one with water so I have like 40 lifetimes worth! LOL! Another great cooling lubricant is ordinary Antifreeze from your car. You can also use water but your bit will not last nearly as long. You can see from the rust I have been using this 5/8 diamond drill for years!
You don't need to much, maybe 1/8 to 1/4 inch deep.

By the way, you can get diamond drill bits nice and cheap all over eBay! I am very partial towards the hole saw style.

One of the tricks to getting a good hole is keeping the speed of your drill LOW. So I have set my drill press to its slowest setting. On my press that is 540 RPMs. Another trick is to keep your bit and your glass cool. We use the coolant for that. We will also go slowly.

You do NOT want to put much pressure on the glass, i.e. don't force the bit. Let it go in slowly with a minimum of pressure. Generally, you want to use just enough pressure to get a good grinding sound. Too much pressure cracks the glass and can also ruin the bit.

To keep things cool, I like to drill for about 5 seconds then back off for 3 to 5 seconds. When you back off, don't pull the bit all the way out of the coolant, leave the bit just submerged to help cool it off.

Here you can see the bit just entered the solution and is touching the glass. YOUR drill should be running before you touch the glass. You might notice the absence of ripples showing that mine is not. Thats because I am drilling at 2 in the morning and for some reason, my wife and my son, Frogboy, didn't want to come take pictures for me. So I'm holding the handle of the drill press down with my right hand and shooting photo's with my left! Forgive me if its blurry!

For the best, cleanest hole, you want to drill about 2/3 of the way through. This was easy for me using the depth stop. Then you flip your glass over, line up the bit to the hole and LIGHTLY clamp it down. Then you reset your ring with more coolant, and finish the hole. Don't worry, I know that is not always possible when drilling a tank instead of flat glass. We will go into that, also.

Here is a shot of the hole about 2/3 drilled through. Then I flipped it and finished it using my lovely yellow clay. As you are about to break through to the other side, you should be very careful about using very little pressure.

Here is a picture of the finished hole. It would be a little cleaner if you are not using a bit that's about 10 years old!

Use your preferred method of cleanup to get the lubricant and glass dust off. Personally, I use a dish soap and a bristle brush. That's right, I said soap! Follow it up with a really good warm water rinse. Finally, I wipe it down twice with rubbing alcohol.

(Whispered) Did he really say soap? I think he did! He said soap!

Back in the day, I constructed 40 Vivs from flat glass using soap on every one. Followed up with rubbing alcohol and never had a problem, from tincs to pumilio's to Thumbs.

OK, now lets talk about drilling without a drill press. I did this one JUST for you! This is the first and only hole I have ever drilled without a drill press. I was successful my first time and YOU CAN BE TOO!! It's not that hard!

First of all, you can't skip the rest of the post and just jump to here figuring that you don't have a drill press. You need to read the first part to get the good stuff about cooling and all that.

Here we are going Native! No suction ring, no drill press, no clamps, no flipping the glass. Just a man, a drill, and his Play-Dough! Ok, modelers clay, Play-Dough just sounded funny

Using a backing board is still a good idea, although I have done it here simply supported on two 2x4's, as if it were a tank that you can't really use a backer board on.

Make your clay ring and put in your coolant of choice.

Ooops! no pics!

As you drill, slowly putting your drill into the upright position, you will notice that the groove you have started helps to hold the bit exactly where you want it. If you try to just drill straight in without angling it, the bit will try to walk all over the glass.

Here you can see we are finally into the upright position, (or close to it).

In pic 2 you see we have drilled through to the other side! Successful the first time I ever tried it!

Now when you drill through glass without flipping the work, it is pretty common to get some chipping. It's no big deal. Works just fine! Here are some blown up shots showing the kind of chipping you might expect. Remember, this is a 5/8 inch hole blown up. These are TINY chips!

Plus, the chips would probably be smaller if my bits weren't 10 years old!

Don't forget your cleanup!

I recently saw a thread where someone asked about drilling into a tank with frogs in it.
I do NOT recommend this!! However, if you must try it, duct tape a rag under the spot you are drilling. Tape all around it to catch any glass bits. Use water instead of cooling lubricant and just figure on ruining a bit.
Ever see an old war movie where they have tape criss-crossed all over the windows? This is to keep broken glass more or less in place when the bombs drop. So criss-cross the top of your tank with masking tape JUST IN CASE! I cannot stress this enough, people, Don't bomb your frogs!! If that glass breaks, you have enough to worry about without your froggys jumping all over the place!

One last thing, I keep seing "Pumilo-Junior Member". It feels kind of nice to be called "junior"!

(Big Booming Voice)
This has been a public service announcement from...Pumilo! Tune in next time for... "How to Cut Glass-So Simple an 11 year old can do it!"

Yes! I know Pumilo is misspelled! I misspelled it 8 years ago on eBay!! Now it's just an inside joke...Duhh!