This project comes with a clear “do not try this at home” warning for two reasons:
- It involves fire and broken glass, so use extreme caution and attempt it only at your own risk.
- Despite multiple attempts, I couldn’t get it to work reliably, so you may not want to spend time on it unless you enjoy experimenting.
I was excited to try this technique after reading instructions in Men’s Health: the idea is to transform beverage bottles into glass tumblers by scoring a line of heat around the bottle and then cooling it rapidly to induce a clean break. Unfortunately, after a dozen or so tries I never achieved consistently usable results.
Still, I’m sharing the process and my findings in case it helps someone else troubleshoot, or at least to show that not every DIY project goes smoothly. I recorded most of the attempts, so there’s a “how‑not‑to” video documenting what happened. Note: I recommend using safety goggles, a fire extinguisher, and heat‑resistant gloves if you try this—Men’s Health didn’t mention them, but they’re wise precautions. Remember: glass plus flame equals risk.
If you can’t watch the video, the written step‑by‑step account follows, including the sanding step that I accidentally left out of the footage.
First, I gathered the supplies recommended by the article:
- Lighter fluid and a small cup to hold it
- Glass bottles
- A lighter or matches
- Scissors
- String
- Cold water (we used a watering can)
- Sandpaper (not pictured)
- Paper towels for cleanup (my addition)
I worked on a spare piece of patio slate to avoid risking heat damage to the driveway. The concept is simple: concentrate heat along a single line near the bottle’s shoulder, then quickly cool the line with cold water so the glass separates, leaving a straight‑sided cup. Tie a string around the bottle where it begins to taper.
On my first test I found one loop of string didn’t generate enough heat on a Boylan’s bottle, so for the Izze bottles I used two loops. After tying the string, remove it and soak it thoroughly in lighter fluid while keeping your fingers dry. Rewrap the soaked string around the bottle and trim any excess that could let the flame run down the bottle.
Because handling the soaked string often left my fingers wet with lighter fluid, I rinsed my hands before lighting anything to avoid accidental burns. The next step is to ignite the string. The article suggested holding the bottle while rotating it so the flame spreads evenly; I tried both holding and leaving the bottle on the slate, usually lighting the string on all sides before setting it down.
The burning string looks dramatic, but I never heard the expected crack after about ten seconds as the article described. When I waited for the flame to die out completely and then poured on cold water, nothing happened. In many attempts, igniting the string and immediately dousing the bottle produced the cracking noise, so timing appeared quite sensitive.
The ideal result, in theory, is a clean horizontal separation that yields a usable tumbler. In practice my breaks were jagged and uneven—definitely not safe to drink from without significant finishing.
I tried smoothing the rim with sandpaper. Sanding did improve the edge, but it required a lot of work to get a flat, even top. Sanding also produces silica dust, so do it outdoors and wear a mask to avoid inhaling particles.
Of the bottles I attempted, a few were marginally acceptable after extensive sanding, but most were too rough or irregular. The Izze bottles posed an additional problem: their logos were plastic labels that melted and burned during the process, which created an unpleasant residue and made the break area harder to finish cleanly.
Hoping a different bottle type would help, I tried thicker IBC Root Beer bottles without plastic labels. The thicker glass was harder to break uniformly; some bottles refused to separate at all, while the ones that did were still jagged. Overall the results were not significantly better.
In the end I discarded all of the attempted tumblers. Some could have been repurposed as small vases if the uneven edges weren’t a concern, but none were suitable as drinkware without a lot more work. I considered several possible failure points: my string thickness, bottle temperature before heating, or simply that certain brands and glass types respond differently. It may be that this technique is hit‑or‑miss, or that it requires specific materials and precise timing that I didn’t achieve.
Have you tried this method or something similar with better results? If so, please share tips and variations—brand recommendations, string type, or timing—that helped you produce safe, clean breaks. Your experience could help others attempt this more successfully and more safely.