Yesterday I talked about building a laser tripwire rig and, why I’m not ready to tell you why I need one, I am ready to tell you what the glycerin was for.

If you take pure glycerin and purified water you can make a simple version of Fog Juice and I needed fog to properly see the lasers and it was a far cheaper to build my own unit.

Once you have the juice it’s a simple matter of turning the liquid to steam and airing it through the room.

My first attempt was using an old hair curler and a broken vacuum I had laying around.


The unit came together perfectly, allowing a gravity fed dipper on to the iron.


I put a pinhole in the bottom of an old Zaxbys cup and it was super effective, dripping it exactly as quickly as I wanted it to and an old PC fan moved it down the hose.


Unfortunately the heating element couldn’t keep up with the liquid. Every other drop would cool the iron so half of the formula would just pool at the bottom of the unit.

I was able to solve this by using a metal pan and putting it on the stove instead.


This worked fantastically, fog bellowed out of the hose as good as the real machine..

… until I turned it up too high and it melted…


To be clear, it wasn’t that the top was made of plastic that was the problem.

I was running a test to see how high the stove needed to be to burn all the liquid and if I had kept the temp where it needed to be it would have worked just fine.

In other words if someone happens to be researching a DYI fog machine, I’m pretty confident this would work for you as long as you keep it MED and below.

But I turned it up to MED HIGH and it melted on me before I could stop it. That’s the price of doing R&D and since the vacuum was trash anyway it was a positive learning experience.


Because I didn’t need the fog to work like a haunted house I was able to move on with my laser experiments by just pouring the fog juice directly onto a hot plate.

This filled the room with harmless fog that left no residue behind so at least I can say for sure the glycerin works as advertised.

In the future if I need fog on demand I may try a combination of the two methods.