Halloween Prop: DIY Fog Machine


Reader [Daniel] told us about a video detailing how to make your own fog machine. This project uses two disposable roasting pans to create a fog chamber. Inside you will find an upside-down clothes iron to convert fog liquid into a gas. The liquid is gravity-fed from a water-bottle reservoir on top, converted to smoke by the hot iron, then the newly created smoke is directed out of the chamber by a 12 volt fan.

You probably have an old iron sitting around (especially if you use the toner transfer method for making PCBs), as well as a fan of some type. The build method used in the video is not at the level we usually look for. Using one blade of a pair of scissors is not what we recommend for stripping wire insulation. We also don’t advocate hot gluing a wire to a battery for a reliable connection (for that you’d want wire glue). But with better building techniques, and perhaps an air intake fan for better fog direction, this has potential.

The project is predicated on the availability of “fog juice”. We’re probably not going to head out and buy a bottle of that so look into making some yourself from glycerin and demineralized water.

30 thoughts on “Halloween Prop: DIY Fog Machine

  1. in my eyes this is a real hack since it is something that i can aford unlike some of the stuff on this site… and i could use fog to make my evil lair even more intimidating mhwahahahahahahahaha

  2. This could be potentially dangerous. Fog machines are designed to work with specific types of fog juice that vaporize at certain temperatures. There’s no telling if heating the fog liquid beyond a certain temperature will produce toxic vapors. The same goes with making your own fog juice. I’ve contemplated it, but haven’t tried it yet. Just be sure that when you do, use pure glycerine that’s food grade.

    1. Most things are potentially dangerous, particularly if you’re hacking them… Breathing is an exceptionally dangerous activity on it’s own. It doesn’t mix well with other basic autonomic processes like drinking, eating, or talking. I’d be more worried about the possibility of inhaling electricity… but maybe that’s just me. ;)

  3. In my opinion (who nobody asked for), a fog machine that actually uses fog liquid to make fog, it’s not a hack in any way.
    C’mon dude, we’re techies.
    Almost anyone here knows how to make a fog machine, even without liquid fog. Having the liquid it’s pancake.

  4. Hackaday commenters are seriously the biggest douches I know of on the internet. Worse than Digg commenters. Heaven forbid these guys should publish a light, easy story or two between big awesome hacks.

    I, for one, did not know that I could throw some water and glycerin in a jug, shake it up, and boil it off to make awesome fog. I am, as a result of this post, pumped to try it this halloween.

  5. How to get the same with a quarter of size and in less time:
    One hot glue pistol (like the one in the video)
    One Christmas tree lights controller for AC.
    One small aquarium air pump.
    Small jar (like a peanuts butter one).
    2 or 3 feet’s of aquarium flexible tubing.

    Making of:
    Do a two small holes in the cap of the jar. Little less than the diameter of the air pipe.
    Cut the tubing in half to get 2 pipes.
    Put one end of the first pipe inside the cap, down to the bottom of the jar.
    Secure the end of the second pipe at 1/4 inch or less after passing the hole.
    Attach the free end of the second pipe to the air pump.
    Plug the air pump into the Christmas lights controller.
    Assure the pipes with the hot glue.
    Disassemble the hot glue to get the heating element.
    Fit the free end of the first pipe to the glue bar intake of the heating element.
    Maybe and depending of the construction of the heating element, will be necessary that another more heat resistant element be fitted between the tubing and the heating element.

    Fill the jar with smoke liquid almost to the top and put the cap on.
    Connect to the wall outlet the heating element.
    Way a few minutes and connect the Christmas light controller too.

    Enjoy the smoke.

    1. Stendall,
      I know this is an old thread and you may not even
      see this, but I have searched all over the Internet to find a simple spill proof model like this.
      You have helped me and probably others 6 years after posting this. Idk if you have actually built this or if it’s just theory, but I am going to put it into motion.
      Thank you!

  6. @Kelseylf Steam NO vapour actually…. I work in theate and fog fluid is generally based on glycerine and water. It certainly does not make steam. I also agree with Zygomatic, fog fluid burnt at the wrong temperature can be carcinogenic.

  7. How long does the fog sit around for? I could see this if it lasted a long time, otherwise I’d just buy a crap ton of dry ice and dunk it in a large bucket of very hot water, and make sure you don’t fill up a whole room with co2.

  8. Zygomatic and anyone who thinks that this is dangerous because it might be the wrong temperature, please answer this question for me….

    How is it possible to get the fluid to evaporate at a temperature higher than it evaporates?

    Or rather, water boils at 212F, so how do we get the water up to 220F?

    The answer is: a fluid will not reach a temperature higher than its evaporation point(for the particular pressure it happens to be). The gas can get hotter but never the liquid.

    So this would be fine and plenty safe.

  9. just a few quick questions, how exactly is this all setup? it doesn’t really go into details on how to mount the iron. Now, why not just us small griddle heating unit in the bottom of the pan, i mean you can get a tiny griddle for cheap and just use the heating source for the machine for halloween, then pull it out afterwards. also, why run a 12 volt fan? you can pick up a little hand fan from wal-mart for like 3 bucks that will run all night on a pair of AA’s. just so long as you figure out a way to mount it. As long as the fog comes out of the box it should not just disperse quickly. you could possibly mount it with just a hole barely big enough for the body of the hand held fan to fit through and cut some slats so the fan can push the air through. As far as making your own fog juice. where i live Fog juice is everywhere, wal-mart, K-mart, Target, Halloween Express, The Party Store, seriously everywhere i have seen that have halloween costumes they have a $30 fog machine and right next to that is a stack of fog Juice Bottles.

    On a Side Note: i happen to notice that no one has mentioned if you make a second chamber with nothing but ice in it connected to the fogger with 2 holes so the fog runs through the second chamber it will cool the fog so the fog doesn’t just fly everywhere. honestly if you are going to have fog for halloween it is best when it sticks to the ground, because when you have the fog come directly out it is coming out at that hot temp and just rises up. it is way better to have a chiller box attached IMO.

  10. Couldn’t you just fill a steam iron with fog juice and let it hang sort of frontways? I have an iron with a little regulator switch to control the flow onto the steam element, it just steams when the iron is tipped down a bit, I’m sure that would work.

  11. irresponsible and dangerous

    Perhaps no component of making fog or smoke is as misunderstood, or as underrated, as the fluids used in the process. Fog fluids used in these processes are made from a series of glycols mixed with water. Glycols are among the most commonly used chemicals in the world and are found in products from food to cosmetics. The choice of which glycols manufacturers use should be made very carefully.

    Fog machines and fluids are designed as systems. Specific fluid formulas require specific temperature for optimum aerosolization during the “flashing” process. Manufacturers of fog equipment design their machines to be compatible with their fluids. If a machine is calibrated at too low a temperature for a given fluid, the result can be “wet” fog that can leave a residue. If the temperature is too high, the fluid can “burn” or decompose the fluid, thus changing its chemical composition. This “burning” can create harmful byproducts.

    In a recent report, an agency of the US Federal Government, the National Institute of Occupational Safety and Health (NIOSH) recommended “using only fog fluids approved by the manufacturers of the machines”. (HETA 90-355-2449)

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