It’s Not Too Late to Build Your Own Halloween Fog Machine

As a maker, you’ve almost certainly been focusing on making a costume for Halloween. But what about your home decorations? Sure, you have probably carved a pumpkin into a good ol’ fashioned jack-o’-lantern, and maybe even strung up some lights and fake cobwebs. To really create a spooky atmosphere, however, you want to make some fog. Fog machines are fairly affordable online, but can be difficult to find the day of Halloween. Fortunately, you may be able to build your own fog machine with parts you already have laying around by following YouTuber GreatScott’s guide.

As GreatScott! explains, fog machines consume “fog juice” to create smoke. That fog juice is made from a mixture of glycol and distilled water. Neither of those is difficult to obtain, but it’s easiest just to purchase the mixture from a local big box or Halloween store — both of which should have plenty of stock this time of year. That fog juice will evaporate and create smoky gas when it is heated up to a suitable temperature—around 200 degrees Celsius, so you just need a way to get it to that temperature.

For his build, GreatScott! used nichrome wire, which is used in a wide variety of devices that need to heat liquids. For example, you’ll find nichrome wire in an e-cigarette heater coil. It may also be possible to use other materials, like copper wire. That just needs to be connected to a suitable power supply to heat up. GreatScott! wrapped the nichrome wire around a wick, which pulls fog juice up out of a 3D-printed container. A fan blows the fog out of the enclosure, and an Arduino measures the fog juice level with a water level sensor and controls the wire and fan. GreatScott! does note that it may be possible for the vapor to be toxic, so be sure to investigate the safety requirements for the fog juice before building this fog machine.