If you wander around any of the popular file saving libraries, you’ve probably seen a number of creative looking candle holders. But do they work with real candles? Will they melt? Will they catch fire? To answer this question, I printed several candle holders in PLA — the most popular and easy to use filament — and put them to the test by lighting them up and watching them burn.
First of all, candles are just stupid hot — somewhere around 1000 Celsius in the hottest part of the flame. (That’s like over 1800 degrees Fahrenheit.) This is why we should never burn candles unattended. If a burning candle is knocked over near curtains or furniture it could quickly cause a fire.
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Hot is a 3d Printer?
The hot end of a 3d printer “only” needs to reach 185 degrees Celsius before it starts to melt PLA. That’s 365 F, hot enough to bake cookies and certainly hot enough to burn your fingers. But it’s totally chill compared to actual fire. If you’ve ever used a lighter to burn off wisps from poor retraction, then you know how easily PLA can go from melty to char.
Testing Prints with Candles
I decided the best way to find out if we can burn a real candle safely in a 3d printed holder is to run a few real life tests. I printed several candleholders of different styles and took them out to the back deck. Some were thick and sturdy prints, while others were delicate and thin. I put the candles on a cookie sheet, set a tea light in each one and turned on the camera. My teenager came along to help.
🔥 We set a few things on fire... 🔥
Our experiment took place in the fall, prime time for holiday candles! I had some Halloween themed orange candleholders, pumpkins and ghosts, and I was looking forward to printing even more in Christmas themes.
Our vase mode ghost obviously wasn’t going to make it, but the other designs held up remarkably well. Eventually we got bored watching candles holders NOT burn and started lighting things directly on fire.
After that, it wasn’t long before the whole cookie sheet was covered in hot wax and melted PLA.
This experiment wasn’t very scientific, so more candle holders were printed. This time I set them up in the garage with a camera and clock and let them burn undisturbed for 3 hours. The vase mode print only took 25 minute to get crispy, but the other candles only got singed around the edges.
I STILL can’t recommend you use REAL candles inside a 3d print. It’s just not safe for long term use.
You’re better off using a battery operated LED candle…ESPECIALLY if you have kids, cats or dogs.
An LED candle doesn’t need to be watched and it doesn’t matter if it gets knocked over. I’ve been using these ever since I became a mom and started worrying about safety hazards. They don’t produce a flame and do not emit heat, making them safer to use in our plastic printed holders, which certainly have not been designed to withstand the heat generated by real candles.
Plus they look really cool in your 3d prints.