4 Ways to Cut Glass Bottles (including the One Way that Actually Works!)

I originally published this tutorial on Crafting a Green World.

The ability to cut a glass bottle all by yourself is the Camelot of crafting. We've all heard of people doing it, we've seen the YouTube tutorials, we've for sure seen the awesome stuff you can make from a cut glass bottle, and yet... if you've ever tried it for yourself, you know that it's not that simple, is it?

If you haven't cut a glass bottle before and you think that it IS simple, go try it. I'll wait here until you come back pissed off and scratched, having cleaned up the mound of shattered glass that you were left with.

Done? Okay, great! Now hang out with me here while I run through the three most popular methods of cutting glass bottles that seem to show up most often online, and I'll tell you why they suck. Your reward is that when I'm done, I'm going to walk you through the one way of cutting glass bottles that actually works like a charm. It takes some special tools, but it's easy and it WORKS.

But first, the three methods that don't work:

Method #1: Score and Tap

It's a bummer that this method is so unreliable because it's the one that's the most commercially available. Most store-bought bottle cutting kits include a jig for the bottle, a wheel that etches the bottle, and a tool for tapping it:

 Here's the bottle cutting kit that I owned for a decade before it finally pissed me off enough that I gave it away.

The idea is that you place the bottle on the jig, turn it so that it's etched by the wheel, and then tap it to break the glass neatly at the etching. Here's an example of what a typical bottle cutter kit looks like:

It... kind of works? Ish? The method is sound, but the problems are that one, it's got a big learning curve, so your first 20-50 bottles aren't going to come out right. Two, it's unreliable, so even after you've finally got the hang of the method, you're still going to crack a bunch of bottles. There's just no getting around it. And that's a lot of waste for a process that's supposedly all about removing glass from the waste stream.

Method #2: Hot and Cold Water

This method is similar to the process above, except that instead of tapping the scoreline, you alternate pouring hot and cold water on it, using the physics of temperature to neatly break the bottle:

That's the idea, at least, but again, a method that involves breaking the bottle, however carefully engineered, is still going to subject you to a lot of trial and error. It's a more elegant solution in that you don't have to physically smack your bottle with a hammer, but you're still going to get so many bottles with wayward cracks, no matter how much you practice. It's not worth the waste.

Method #3: String and Fire

Oh my gosh, I so badly wish that this method worked better because you KNOW how much I love myself a good fire! For this method, you only slightly endanger your life by soaking a string in a flammable substance, wrapping it around a bottle, and then SETTING THAT STRING ON FIRE:

YAAAAAASSSSS!!!!! Who does not love setting stuff on fire?! Unfortunately, not only is this method exactly as unreliable as the first two but it also, you know, physically endangers you. Sigh...

Method #4: Just Cut It, Bro (the one that works!)

Okay, Sugar, you've been so patient with me first telling you all the ways that don't work for cutting a glass bottle that now I'm going to give you a present by telling you the way that DOES work.

You might have noticed that the three unreliable methods that I've shown you all have something in common: they break the bottle. Sure, you can get the hang of it and break the bottle just right more often than not, but there's still too much luck involved for my taste. In my opinion, the best method for cutting a glass bottle is to do just that: get yourself a rotary tool with a glass-cutting bit, and cut that bottle!

I use an older Dremel 4000 with a diamond cutting wheel attached. That, plus a trickle of water, plus some safety gear, plus a few grits of sandpaper, is all you need to cut a bottle accurately every time, no luck needed, with a very short learning curve.

Directions

1. Mark your cutting line.

Do this with a Sharpie, not masking tape or anything water soluble. You can mark curves, but keep in mind the turning radius of your cutting wheel--it's not a jigsaw.

2. Put on your safety gear.

You absolutely need a breathing mask to do this method. No excuses. I am not responsible for you filling your lungs with glass dust, so don't even think about not doing what I say. I use this type of mask, which is also good for soapmaking. The bottle will get slippery when it's wet, so a rubber glove on your bottle-holding hand won't steer you wrong, either.

 Me + weapon + victim: let the games begin!

3. Start the water flowing.

Run your faucet or hose so that lukewarm water will trickle over your bottle, right at the spot where you're cutting. Keep that water at your cutting location the whole time you're cutting. If your aim is off, you WILL crack that bottle, so don't let your mind wander.

4. Cut slowly, all the way around.

Hold the bottle steady in your non-dominant hand, and the Dremel steady in your dominant hand. Keep the Dremel itself out of the water, but make sure that water is flowing over your cutting location, and then just let the cutting wheel do all the work. Be especially careful when you're almost all the way around, as that last half-inch or so is the most likely to chip.

5. Sand the edges.

You can grind down sharp edges using a grinding bit on your Dremel, but I actually love the way that this guy sands down his glass by hand, and so I do mine the exact same way:

The only difference is I stop after the 320 grit because I just need to not cut my face off via my new drinking glass, not have the shiniest rims on the block:

My favorite thing about this method is how consistent it is. Whether you've got a bumpy, embossed glass, or a thin-walled beer bottle, or a wine bottle made of HUGELY thick glass, you'll cut it pretty much perfectly, pretty much your first time trying. It's way better than breaking your bottle and hoping for the best.