History

Their place was first taken by glycol foggers (just heat up something else), and then pressurized-air machines that "cracked" an oil-based fluid into tiny droplets.

Home-built oil crackers have been used in haunts for a long time. JB Corn was the first to describe the effect on Halloween-L, in a posting in April 1997. I think he also mentioned it in his books.

At about this time, commercial oil crackers fell into disrepute, as people realized that - even if the oil no longer turned into a carcinogen by heat - it was still dangerous to breathe oil vapor.

In the Summer of 2000, haunters rediscovered in a big way oil crackers using mineral oil, when Roger Hunter gave a demonstration of "Free Fog" at the Midwest Gathering (16 August 2000). (Hunter credits Leonard Pickel, who probably got it from JB Corn's posting in 1997; they were both on the list at the time.)

News of the incredible free fog flashed through the e-mail lists; Keeba put up a web page describing Hunter's seminar, with photos by Mark Souza:
http://www.hedstorm.net/HOMEHAUNT/instructions/freefog
and a flurry of postings were made to the mailing lists and the web extoling the new technology.

Revival

Subject: FreeFog Mineral Oil Fogger - Questions
From: "Scott Brunell" 
Date: Thu, 28 Sep 2000 21:32:58 -0400

Well, I took the time today and put together one of these very simple
foggers. Let me tell you what I've learned, and perhaps anyone else who's
playing with one of these (and I know you are) can share their experiences
as well.

First of all, I found what I think is a great container to use for this
project - a 1 or 1.5 gallon red plastic gas can. Its cheap, the right size,
sturdy, would be hard to tip over, has a built in spout for pointing the fog
in the right direction, a small hole just the right size for a 1/4 inch
copper pipe and a built-in handle. No modification is needed to the
container at all. I've pumped a good amount of air pressure through and
there have been no spills or splashes. And, when the season is over, the
whole container seals up nice and tight!

I have no idea how or why this fogger works, but it does work. Does anyone
know the physics behind this? I'm sure it would help in the fine-tuning.

I tried mine out in the garage, and the wind (though there was very little)
drew most of the fog outside and away before it had a chance to collect.
Still, it was coming out fairly quickly and would probably work great
indoors. There was noticeable fog inside the garage and you could see it
trailing outside.

I was using baby oil, and the fog seems to be less visible than your typical
fog. It also has the distinct baby-ish smell. My first mini-experiment was
with olive oil (it was close at hand) and I think the fog was more visible
than the baby-oil fog. Has anyone tried other oils? Any comments on
visibility/odor? (Hmmm - what kind of oil smells "spooky"?)

As you would expect, higher air pressure equals more fog.

At first I was concerned about residue. Again, I'm not sure yet how the fog
is produced, but I would suspect _some_ of the oil must get into the fog
(the odor sure does). I ran the fogger for about 10 minutes onto a piece of
cardboard, and there was no trace on the cardboard at all.

The fog that comes out is fairly cool, though it did not show any tendency
to stay near the ground (outside, anyway - I don't know about inside).
Chilling it should be fairly easy. Others have mentioned dunking a long air
hose into a cooler or using cold oil (what do you suppose my wife would say
if she found a gas can in the fridge :-). I'm not sure how these would
affect the fog, but I will probably try one or both of them over the next
week or so.

If anyone has any experiences to share or experiments that they'd like me to
try, I'd love to hear from you.

- - -

Subject: RE: Hall: FreeFog Mineral Oil Fogger - Questions
From: "Scott Brunell" 
Date: Fri, 29 Sep 2000 08:30:54 -0400

My first experiment was a "proof-of-concept" - it was a blowgun into a cup
of olive oil. The olive oil fog did have an odor, but it was not as
un-spooky as the baby oil. The slimy oil that was spurted all over my hand
was pretty spooky (hey, you have to make some sacrifices when you run cheap
experiments! :-)

The blowgun worked, so I went out and got some copper tubing. The copper
tubing worked, so I crushed the end a bit. I couldn't tell if this helped
or not. I started with 20-25 PSI, which was fine, then upped it to 30-35,
just for fun. There was more air moving through and thus more output, but
not a drastic change.

My next planned experiment is to:
A.) Get plain old mineral oil.
B.) Close the end of the copper tube and drill (or punch, with one of those
clamps from a refrigerator ice machine kit) about a dozen holes in the tube,
spaced maybe 1/2 inch apart.

If this works out, my ultimate plan is to bend the end of the copper tube
into a large circle, maybe 6-8 inches in diameter. Then drill small holes
in the sides of the circle and immerse it in a large black plastic cauldron
of oil. Pump air through it and you should get a bubbling, smoking
cauldron.

It would be wonderful if the oil glowed under black light, but I suspect it
doesn't. Maybe I'll throw in a dash of RIT W&B...

- - -

Subject: Mineral oil fogger (long)
From: JonS999@aol.com
Date: Tue, 14 Nov 2000 11:22:54 EST

I finally got around to trying the mineral oil fogger idea. Surprisingly it 
works great! The fog is not quite as thick as with a fog machine but it is
thicker than a hazer.

Here are the specs on my prototype:

- 1 quart of mineral oil in a 1 gallon bucket
- 1/2" crimped copper nozzle
- 30 PSI input air pressure
- Estimated output - 400 cf/minute
 
I learned -

The fogger shoots mineral oil all over the place, this was remedied by 
placing a cloth "filter" over the output nozzle. Other than that the fogger 
lost no noticable amount of oil after a half hour of use. The fog was 
oderless and tasteless. In a second experiment i chilled the mineral oil to 
just above it's freezing point (it was kinda thick like syrup) the chilled
fog lyed low for only about 10 seconds before rising. My next step will be to 
hook up a conventional fog chiller.

I have just one question. Does anybody know how this thing works yet? I 
theorize it could be from the compressed air chilling the copper nozzle 
creating the same kind of fog you exhale on a cold day.

In the next few days i will attempt to build a mineral oil fogger inclosed in 
a metal box so it looks like a conventional fog machine. If i can find a good 
filter, an/or build some type of trap (like under your sink) the fogger will 
be pretty close to 100% efficient as far as mineral oil goes. 

Has anyone else tried this fogger yet?

- - -

Subject: RE: Hall: Mineral oil fogger (long)
From: "Scott Brunell"
Date: Tue, 14 Nov 2000 13:30:13 -0500

I toyed with this fogger for a while pre-season. The output (at 30 psi) is
OK for an indoor room, but even then the "fog" is pretty thin. I tried a
few various crimps/holes in the nozzle, but nothing made much of a
difference. I also used a few different oils (baby oil, mineral oil,
vegetable oil) and, short of introducing various odors, there was no
distinguishable difference in output. Higher air pressure produced more
output, but the fog was still very thin.

The one thing that I was happy with was my choice of containers - a 1 gallon
Rubbermaid red plastic gas can. A 1/4 inch copper pipe just fit through the
air hole at the back, and the fog shoots out the spout. Made it easy to
send the fog in a particular direction, kept the mess inside, is nice and
stable and has a built-in handle to boot!

Additives

Most hobbiest reports on oil-cracking foggers note that the fog carries the scent of the oil used, such as baby oil or olive oil - which is another good sign for additives.

Health