Having issues drilling tank

[Schlafrig]

In preparation for drilling my new 75 gallon I thought I would to a test run on an old 10 gallon I had laying around. Both times it was going good right until towards the end where it cracked both times. Im drilling pretty slow and not using much pressure. My only thought is maybe I dont have enough water, I was stopping every few seconds to add water since I didnt have somebody to help. Is there anything that I should do differently? Or could it be an issue with the glass being thin on the 10 gallon?

Thanks

 

[KrisReef]

Thin glass is more difficult than thicker as it deforms (and breaks) when the tool binds up.

Put a garden hose on the work and let it run while you drill .

Let the tool do the work, hold the motor as steady as possible. Pushing through at the end can easily break the glass, the tool grinds, not cuts through the glass. Hold the drill parallel to the glass and let it grind through evenly until the last bit gives way.

 

[troublemaker]

I’ve drilled enough tanks to just be dangerous with my advice, but 10 gallons are incredibly hard to drill because of the glass being so thin, so don’t consider it a failure. I normally use vegetable oil and a small piece of board with a hole slightly larger than the bit and another small piece on the back side. I clamp the boards with wood clamps, you don’t need a lot of pressure, just enough to keep the boards in place. I fill the hole with oil, go slow and constantly dip the bit in a bowl of oil, let the weight of the drill be the pressure. You want the cut material to keep overflowing out of the board. The hardest part is the end, that’s normally where it goes bad. I have never had issues on glass at least 1/4”, but have broken thinner glass.

 

[Schlafrig]

Thin glass is more difficult than thicker as it deforms (and breaks) when the tool binds up.

Put a garden hose on the work and let it run while you drill .

Let the tool do the work, hold the motor as steady as possible. Pushing through at the end can easily break the glass, the tool grinds, not cuts through the glass. Hold the drill parallel to the glass and let it grind through evenly until the last bit gives way.

Should I be applying any pressure or just let the weight of the drill apply pressure?

 

[landlubber]

Should I be applying any pressure or just let the weight of the drill apply pressure?

"Let the tool do the work" means avoid applying pressure.

 

[Mr. Mojo Rising]

My tips are don't put any pressure at all, let the drill do the work, just hold it straight, it took me about 20 minutes per hole. Add lots of water. Tape under the glass, so when you drill the weight of the glass doesn't pull it down and chip, use tape to keep the glass in place until you push through it

 

[exnisstech]

I've only drilled a couple but I used wood as guide like @troublemaker described above. As mentioned let the weight of the drill do the work, don't push on it.
Your probably not using a corded drill but I'll mention it anyway, a battery drill should be used if your cooling the drill with running water.