Slashdot Mirror
Fun with Fog Generators
BoomZilla writes "Only
10 or so shopping days to Halloween. If you're at a loss for a project
this weekend check out gotfog.com for
a full set of detailed instructions on the construction of a Fog
chiller. "What's a fog chiller?" you may ask. And rightly so.
Let me explain. A fog machine dumps fog juice on a heating plate to
produce oodles of the white, floaty stuff. Problem is that it doesn't
hug the ground like you see in the movies. An alternative that is employed
to create the ground-hugging variety of fog is a dry ice machine (which
heats up dry ice and disperses the resultant cloud of fog). The problem is
that dry ice is (a) expensive and (b) not always that easy to get. Enter
the fog chiller. The chiller can be built very inexpensively (major cost
is the sacrifice of a largish cooler) and works with a regular fog machine
that consumes low-cost fog juice. Go on, give it a try. You know you want
to. And just imagine the look on the faces of your little ghouls and
ghosts come the 31st when your house looks like boot hill on steroids."
The problem is that dry ice is (a) expensive and (b) not always that easy to get.
He obviously hasn't heard of the wonder which I like to call a "grocery store." It's sold at most supermarkets for $0.99/lb. around here...
Here's the Google cache of the page on building a fog chiller.
-IOVAR Web Dev Platform
Use a container (I use a Tupperware box) that is twice as big as the volume of grass you wish to dry. Make a few small holes in the lid, to allow the gas to escape. Put equal volumes of bud and dry ice inside, loosely packed, with the dry ice underneath the bud. Put the lid on and make sure it is properly sealed so that the only way for gas to escape is through the holes in the lid. Put the box into a freezer, lid upwards. This is to keep the material as cold as possible, prolonging the sublimation process for as long as possible. The dry ice will begin to sublime pushing all air out of the box and surrounding your buds with bone dry co2. The totally dry atmosphere will begin drawing water molecules out of the plant material. Check the tub after 24 hours and then every 24 hours until the dry ice has all gone. When the ice is all gone -the buds should be completely dry and smokeable. If you find that they are not quite dry then put some more dry ice into the box, place the lot back in the freezer and wait until they are done.
the site seems to be slashdotted now (is this happening more frequently than it used to?)
but here are plans to build your own fog/smoke machine http://www.juggling.org/help/misc/fog.html
Packing the chiller with ice, then shoving some dry ice inside the cooling tube works a little better. The dry ice cools the fog, and the regular ice keeps the dry ice from evaporating too fast.
OOh, finally, something on Slashdot that I can comment authoritatively on! (I'm a stagehand, and often use atmospheric effects)
I would just like to refute the posters assertations about dry ice foggers. Firstly, dry ice is certainly NOT expensive. Prices usually fall in the $0.50 to $1.00 / lb range, depending on the form (block, pellets, etc.) and supplier. Which brings me to the second point, availability - Go to your local grocery store. If they don't have it (most in southern and western states usually will), they'll be able to tell you who will.
Once you have the dry ice (I'd suggest about 25-35 lbs. for a good, long show), it's very easy to turn it into fog. Step 1 - pour hot water over it. Step 2 - there is no step 2! There are many many pre-made machines for this purpose, such as the City Theatrical Aquafogger, which are available for rental, but it's such a simple device, anyone here should easily be able to make one on their own.
The basic things you need are as follows - a barrel - big enough to hold the dry ice, plus all the hot water that will be poured through it. A basket, to hold the dry ice in, above the level of the water. A fan and a tube, to take the resultant fog, and put it where you want it (dryer hose works very well for this). And finally, a method for pouring large amounts of very hot water over the dry ice - the faster the rate of pour, the faster the sublimation of the dry ice, and hence, the larger the volume of fog generated. For the water-pouring, something as simple as a 5-gallon pail is quite sufficient.
One down side to a dry-ice fogger, however - that 25lb load will only last about 10 minutes, and the fog only a few minutes longer than that. If the effect that you're looking for is a long-lasting, room-filling, hanging haze, then you'll be better off with an oil-based fogger. (Just avoid prolonged breathing of concentrated amounts of the fog - it's been shown to produce many respiratory ailments - and that was the professional stuff)
If all the world's a stage, anyone who says they want better lighting spends far too much time in a dark theatre.
The problem with dry ice is that it's dangerous (CO2 asphyxiation) in closed areas, and outdoors nothing will work terribly well.
I've put up a mirror of the special projects page at gotfog.com, as well as the "making fog hug the ground" and "vortex" special projects. The mirror should be significantly faster than the original, and can be found at http://www.msu.edu/~brownd41/mirror/gotfog/index.h tml
I built one of these for my drama class in high school. The problem was, we used DRY ICE as the chilling mechanism for the fog. Blow fog though a cooler full of dry ice, and it'll chill down pretty fast. The good news about this is 1) no water from regular ice. 2) dont need much dry ice. We found that 1-2 pounds of the stuff was more than sufficent to last us through a day of competition. Plus, you can toss some pennies on it for a neat metal contracting sound. The problem we ran into was forcing the fog through with the correct speed to both chill the fog into hugging the floor and also producing any kind of fog volume. We fixed that with a fan from radio shak wired into a battery pack so it would be portable enough. After that the only problem was rolling huge blankets of fog off the edge of the stage and into the audience.
No one expects the Spanish Inquisition!
The problem with dry ice is that it's dangerous (CO2 asphyxiation) in closed areas. Not if you ventillate right. Remember that CO2 is heavier than air, so a high vent and a low vent solvethe problem.
I hereby place the above post in the public domain.
For those about to become embarrased by saying Samhain out loud, it is generally pronounced as "So-wen" or "Sah-wen" (or sometimes "Sha-wayn" or "Sho-ween") due to some funky grammar that I can't completely grasp in its entirety. For a simple nmemonic, or whatever this might be called, flip the m upside-down to a w and then pronounce. Easy, no? I won't make spelling comments, since I'm on a laptop with a strange keyboard...
:-)
Yes, it is kind of funny how the replies go up in their default moderation points.
fair.org counterpunch.com truthout.com indymedia.org salon.com
eff.org guerrilla.net debian.org gentoo.org
Ack! The only thing that will stink up your kitchen worse is doing knife hits off the burners.
I am a theatrical sound & lighting designer and these are the fog products that I have used for years ... but it might be more fun to build one yourself. :-)
Rosco Fog Products
Mirror with as many images as wget could fetch. The box can't handle much load, but every little bit helps.
It is funny how many people actually think this. Then when you ask them where they checked on prices lately, "I heard it from a friend". I have purchased dry ice a few times over the past few years for camping trips to keep some perishables cool. I usually pay less then $0.75/lb. Here is an example for a company in Tampa, FL. http://www.dryicesales.com/products.htm
Built mine last week - saw the plans last year on http://www.halloween-magazine.com/sfx/index.html, and thought it'd be a good idea if it actually worked. I haven't tried it with a full cooler of ice (used 20 lbs, filled about half), but there was a noticable "low lying" quality to the fog, and I expect even better results when I have a full cooler, or one with dry ice. Well worth the $25-$30 total price tag.
On the subject of dry ice, there are several posts talking about dry ice being "cheap" at $1 a pound. Sure, $1 isn't very expensive, until you realize that in order to have party/stage effects, and fog for the duration of an evening of trick-or-treaters or a party, you're going to need at least 100lbs of the stuff. At that, it's not even a thick/can't see through it amount, it's just the "creepy fog" effect. As ShinmaWa noted, you'd need upwards of hundreds of pounds for a true movie like effect. Sufficently chilled fog through a cooler (while not as think as dry ice fog) will run you less than $20 in fog juice.
I don't know about you, but spending hundreds on one night of fog is expensive for me, and is probably expensive for most people.
How is this a flamebait?
It's not, but since nobody uses the meta-moderation feature, incompetent moderators are never busted.
To ensure perfect aim, shoot first and call whatever you hit the target
Someone else has already said that this is finally a topic that they can contribute to, but I've been generating a nice, low-lying, thick and clingy fog for my "haunted yard" for the past 8 years.
...
... pass the fog through a cooler of wet ice (some cooling, but significant humidification), THEN pass it through an aluminum duct (flexible dryer ducting works best) full (to half-height) of dry ice (that's chilling) ... solves all of the world's fog problems.
The "classic" fog chiller, using coolers, fans and regular ice is a good start, but misses the key points for cold environments.
In order to make a thick, low-lying fog using a cheap fog machine, you need to do two things (particularly here in Canada, where we often get Halloween close to freezing):
1) Humidify the fog (often forgotten)
2) Cool the fog below the ambient temperature
The classic technique accomplishes both of these by passing the fog through a cooler of "wet" ice. As my friends in New England and Minnesota know, this don't do squat when the ambient temperature is around freezing
So
But, remember:
1) Don't cuddle with the dry ice
2) Don't use any of this to cool a processor
The Origins of Halloween
... We see that this holiday has its origin, basis and root in the occultic Druid celebration of the dead. Only they called it 'Samhain', who was the Lord of the Dead (a big demon)".1 When these books and pamphlets cite sources at all, they usually list the Encyclopedia Britannica, Encyclopedia Americana, and the World Book Encyclopedia. The Britannica and the Americana make no mention of cats, but do indeed list Samhain as the Lord of Death, contrary to Celtic scholars, and list no references. The World Book mentions the cats and calls Samhain the Lord of Death, and lists as its sources several children's books (hardly what one could consider scholarly texts, and, of course, themselves citing no references).
... the evidence for the cat as an important cult animal in Celtic mythology is slight".9 She cites as supporting evidence the lack of archaeological artifacts and literary references in surviving works of mythology.
copyright © 1989, Rowan Moonstone
In recent years, there have been a number of pamphlets and books put out be various Christian organizations dealing with the origins of modern-day Halloween customs.
Being a Witch myself, and a student of the ancient Celts from whom we get this holiday, I have found these pamphlets woefully inaccurate and poorly researched. A typical example of this information is contained in the following quote from the pamphlet entitled "What's Wrong with Halloween?" by Russell K. Tardo. "The Druids believed that on October 31st, the last day of the year by the ancient Celtic calendar, the lord of death gathered together the souls of the dead who had been made to enter bodies of animals, and decided what forms they should take the following year. Cats were held sacred because it was believed that they were once human beings
In an effort to correct some of this erroneous information, I have researched the religious life of the ancient Celtic peoples and the survivals of that religious life in modern times. Listed below are some of the most commonly asked questions concerning the origins and customs of Halloween. Following the questions is a lengthy bibliography where the curious reader can go to learn more about this holiday than space in this small pamphlet permits.
1.
Where does Halloween come from?
Our modern celebration of Halloween is a descendent of the ancient Celtic festival called "Samhain". The word is pronounced "sow-in", with "sow" rhyming with "cow".
2.
What does "Samhain" mean?
The "Irish-English Dictionary" published by the Irish Texts Society defines the word as follows: "Samhain, All Hallowtide, the feast of the dead in Pagan and Christian times, signalling the close of harvest and the initiation of the winter season, lasting till May, during which troop swere quartered. Fairies were imagined as particularly active at this season. From it, the half-year is reckoned. Also called Feile Moingfinne (Snow Goddess)."2 The "Scottish Gaelic Dictionary" defines it as "Hallowtide. The Feast of All Souls. Sam + Fuin = end of summer."3 Contrary to the information published by many organizations, there is no archaeological or literary evidence to indicate that Samhain was a deity. Eliade's "Encyclopedia of Religion" states as follows: "The Eve and day of Samhain were characterized as a time when the barriers between the human and supernatural worlds were broken... Not a festival honoring any particular Celtic deity, Samhain acknowledged the entire spectrum of nonhuman forces that roamed the earth during that period."4 The Celtic Gods of the dead were Gwynn ap Nudd for the British and Arawn for the Welsh. The Irish did not have a "Lord of Death" as such.
3.
Why was the end of summer of significance to the Celts?
The Celts were a pastoral people as opposed to an agricultural people. The end of summer was significant to them because it meant the time of year when the structure of their lives changed radically. The cattle were brought down from the summer pastures in the hills and the people were gathered into the houses for the long winter nights of story-telling and handicrafts.
4.
What does it have to do with a festival of the dead?
The Celts believed that when people died, they went to a land of eternal youth and happiness called Tír na nOg. They did not have the concept of Heaven and Hell that the Christian Church later brought into the land. The dead were sometimes believed to be dwelling with the Fairy Folk, who lived in the numerous mounds, or sidhe, (pronounced "shee" or "sh-thee") that dotted the Irish and Scottish countryside. Samhain was the new year to the Celts. In the Celtic belief system, turning points such as the time between one day and the next, the meeting of sea and shore or the turning of one year into the next, were seen as magickal times. The turning of the year was the most potent of these times. This was the time when the "veil between the worlds" was at its thinnest and the living could communicate with their beloved dead in Tír na nOg.
5.
What about the aspects of "evil" that we associate with the night today?
The Celts did not have demons and devils in their belief system. The fairies, however, were often considered hostile and dangerous to humans because they were seen as being resentful of man taking over their land. On this night, they would sometimes trick humans into becoming lost in the fairy mounds where they would be trapped forever. After the coming of the Christians to the Celtic lands, certain of the folk saw the fairies as those angels who had sided neither with God or with Lucifer in their dispute and thus were condemned to walk the Earth until Judgment Day.5 In addition to the fairies, many humans were abroad on this night causing mischief. Since this night belonged neither to one year or the other, Celtic folk believed that chaos reigned and the people would engage in "horseplay and practical jokes".6 This also served as a final outlet for high spirits before the gloom of winter set in.
6.
What about "trick or treat"?
During the course of these hijinks, many of the people would imitate the fairies and go from house to house begging for treats. Failure to supply the treats would usually result in practical jokes being visited on the owner of the house. Since the fairies were abroad on this night, an offering of food or milk was frequently left for them on the steps of the house so the homeowner could gain the blessing of the "good folk" for the coming year. Many of the households would also leave out a "dumb supper" for the spirits of the departed.7 The folks who were abroad in the night imitating the fairies would sometimes carry turnips carved to represent faces. This is the origin of our modern Jack-o-lantern.
7.
Was there any special significance of cats to the Celts?
According to Katherine Briggs in "Nine Lives: Cats in Folklore", the Celts associated cats with the Cailleach Bheur, or Blue Hag of Winter. "She was a nature goddess, who herded the deer as her cattle. The touch of her staff drove the leaves off the trees and brought snow and harsh weather."8 Dr. Anne Ross addresses the use of divine animals in her book "Pagan Celtic Britain" and has this to say about cats: "Cats do not play a large role in Celtic mythology
8.
Was this also a religious festival?
Yes. Celtic religion was very closely tied to the Earth. The great legends are concerned with momentous happenings which took place around the time of Samhain. Many of the great battles and legends of kings and heroes center on this night. Many of the legends concern the promotion of fertility of the Earth and the insurance of the continuance of the lives of the people through the dark winter season.
9.
How was the religious festival observed?
Unfortunately, we know very little about that. W.G. Wood-Martin, in his book "Traces of the Elder Faiths of Ireland", states: "There is comparatively little trace of the religion of the Druids now discoverable, save in the folklore of the peasantry and the references relative to it that occur in ancient and authentic Irish manuscripts are, as far as present appearances go, meager and insufficient to support anything like a sound theory for full development of the ancient religion."10 The Druids were the priests of the Celtic peoples. They passed on their teachings by oral tradition instead of committing them to writing, so when they perished, most of their religious teachings were lost. We do know that this festival was characterized as one of the four great "Fire Festivals" of the Celts. Legends tell us that on this night all the hearth fires in Ireland were extinguished and then re-lit from the central fire of the Druids at Tlachtga, 12 miles from the royal hill of Tara. This fire was kindled from "need fire" which had been generated by the friction of rubbing two sticks together, as opposed to more conventional methods (such as the flint-and-steel method) common in those days.11 The extinguishing of the fires symbolized the "dark half" of the year, and the re-kindling from the Druidic fires was symbolic of the returning life hoped for and brought about through the ministrations of the priesthood.
10.
What about sacrifices?
Animals were certainly killed at this time of year. This was the time to "cull" from the herds those animals which were not desired for breeding purposes for the next year. Most certainly, some of these would have been done in a ritual manner for the use of the priesthood.
11.
Were humans sacrificed?
Scholars are sharply divided on this account, with about half believing that it took place and half doubting its veracity. Caesar and Tacitus certainly tell tales of the human sacrifices of the Celts, but Nora Chadwick points out in her book "The Celts" that "it is not without interest that the Romans themselves had abolished human sacrifice not long before Caesar's time, and references to the practice among various barbarian peoples have certain overtones of self-righteousness. There is little direct archaeological evidence relevant to Celtic sacrifice."12 Indeed, there is little reference to this practice in Celtic literature. The only surviving story echoes the tale of the Minotaur in Greek legend: the Fomorians, a race of evil giants said to inhabit portions of Ireland before the coming of the Tuatha Dé Danann (or "people of the Goddess Danu"), demanded the sacrifice of 2/3 of the corn, milk and first-born children of the Fir Bolg, or human inhabitants of Ireland. The Tuatha Dé Danann ended this practice in the second battle of Moy Tura, which incidentally, took place on Samhain. It should be noted, however, that this story appears in only one (relatively modern) manuscript from Irish literature, and that manuscript, the "Dinnsenchus", is known to be a collection of fables. According to P.W. Joyce in Vol. 2 of his "Social History of Ancient Ireland", "Scattered everywhere through our ancient literature, both secular and ecclesiastical, we find abundant descriptions and details of the rites and superstitions of the pagan Irish; and in no place -- with this single exception -- do we find a word or hint pointing to human sacrifice to pagan gods or idols."13
12.
What other practices were associated with this season?
Folk tradition tells us of many divination practices associated with Samhain. Among the most common were divinations dealing with marriage, weather and the coming fortunes for the year. These were performed via such methods as ducking for apples and apple peeling. Ducking for apples was a marriage divination. The first person to bite an apple would be the first to marry in the coming year. Apple peeling was a divination to see how long your life would be. The longer the unbroken apple peel, the longer your life was destined to be.14 In Scotland, people would place stones in the ashes of the hearth before retiring for the night. Anyone whose stone had been disturbed during the night was said to be destined to die during the coming year.
13.
How did these ancient Celtic practices come to America?
When the potato crop in Ireland failed, many of the Irish people, modern descendants of the Celts, emigrated to America bringing with them their folk practices which were remnants of the Celtic festival observances.
14.
We in America view this as a harvest festival. Did the Celts also view it as such?
Yes. The Celts had 3 harvests. Aug 1, or Lammas, was the first harvest, when the first fruits were offered to the Gods in thanks. The Fall Equinox was the true harvest. This was when the bulk of the crops would be brought in. Samhain was the final harvest of the year. Anything left on the vines or in the fields after this date was considered blasted by the fairies ("pu'ka") and unfit for human consumption.
15.
Does anyone today celebrate Samhain as a religious observance?
Yes. Many followers of various pagan religions, such as Druidism and Wicca, observe this day as a religious festival. They view it as a memorial day for their dead friends and family, much as the mainstream US does the national Memorial Day holiday in May. It is still a night to practice various forms of divination concerning future events. It is also considered a time to wrap up old projects, take stock of one's life and initiate new projects for the coming year. As the winter season is approaching, it is a good time to do studying on research projects, and also a good time to begin handwork such as sewing, leatherworking, woodworking etc., for Yule gifts later in the year. And while "satanists" are using this holiday as their own, this is certainly not the only example of a holiday (or even religious symbols) being "borrowed" from an older religion by a newer one.
16.
Does this involve human or animal sacrifice?
Absolutely NOT! Hollywood to the contrary, blood sacrifice is not practiced by modern followers of Wicca or Druidism. There may be some people who think they are practicing Wicca by performing blood sacrificing but this is not condoned by reputable practitioners of today's neo-Pagan religions.
FOOTNOTES:
1. Tardo, Russell K., "What's Wrong with Halloween?", Faithful Word Publishers, (Arabi, LA, undated), p. 2
2. Rev. Patrick Dinneen, "An Irish-English Dictionary", (Dublin, 1927), p. 937
3. Malcolm MacLennan, "A Pronouncing and Etymological Dictionary of the Gaelic Language", (Aberdeen, 1979), p. 279
4. "The Encyclopedia of Religion", ed. Mircea Eliade, "Halloween" by Primiano, (New York, 1987) pp. 176-177
5. Alwyn & Brinley Rees, "Celtic Heritage", (New York, 1961), p. 90
6. W.G. Wood-Martin, "Traces of the Elder Faiths of Ireland", Vol. II, (Port Washington, NY, 1902), p. 5
7. Kevin Danaher, "The Year in Ireland", (Cork, 1972), p. 214
8. Katherine Briggs, "Nine Lives: Cats in Folklore", (London,1980), p.5
9. Dr. Anne Ross, "Pagan Celtic Britain", (London,1967), p. 301-302
10. Wood-Martin, op. cit., p. 249
11. Rees & Rees, op. cit., p. 90
12. Nora Chadwick, "The Celts", (Harmondsworth, 1982), p. 151
13. P.W. Joyce, "A Social History of Ancient Ireland", Vol.2, (New York, 1968), pp. 282-283
14. Madeleine Pelner Cosman, "Medieval Holidays and Festivals", (New York, 1981), p. 81
BIBLIOGRAPHY:
* Bord, Janet & Colin, "The Secret Country", (London: Paladin Books, 1978)
* Briggs, Katherine, "Nine Lives, Cats in Folklore", (London: Routledge & Kegan Paul, 1980)
* Chadwick, Nora, "The Celts", (Harmondsworth, England: Penguin Books, 1982)
* Coglan, Ronan, "A Dictionary of Irish Myth and Legend", (Dublin: 1979)
* Cosman, Madeleine Pelner, "Medieval Holidays and Festivals", (New York: Charles Scribner's Sons, 1981)
* Danaher, Kevin, "The Year in Ireland", (Cork, Ireland: The Mercier Press, 1972)
* Dinneen, Rev. Patrick S., M.A., "An Irish-English Dictionary", (Dublin: The Irish Texts Society, 1927)
* Joyce, P.W., "A Social History of Ancient Ireland", (New York: Benjamin Blom, 1968)
* MacCana, Proinsias, "Celtic Mythology", (London: The Hamlyn Publishing Group Limited, 1970)
* MacLennan, Malcolm, "A pronouncing and Etymological Dictionary of the Gaelic Language", (Aberdeen: Acair and Aberdeen University Press, 1979)
* MacNeill, Maire', "The Festival of Lughnasa", (Dublin: Comhairle Bhealoideas Eireann, 1982)
* Powell, T.G.E., "The Celts", (New York: Thames & Hudson, 1980)
* Primiano, Leonard Norman, "Halloween" from "The Encyclopedia of Religion", ed. Mircea Eliade, (New York, McMillan Publiching Co., 1987)
* Rees, Alwyn and Brinley, "Celtic Heritage, Ancient Tradition in Ireland and Wales", (New York: Thames & Hudson, 1961)
* Ross, Dr. Anne, "Pagan Celtic Britain", (London: Routledge and Kegan Paul, 1967)
* Sharkey, John, "Celtic Mysteries", (New York: Thames & Hudson, 1975)
* Spence, Lewis, "British Fairy Origins", (Wellingborough: Aquarian Press, 1946)
* Squire, Charles, "Celtic Myth & Legend, Poetry & Romance", (New York: Newcastle Publishing Co., Inc., 1975)
* Toulson, Shirley, "The Winter Solstice", (London: Jill Norman & Hobhouse, Ltd., 1981)
* Wood-Martin, W.G., "Traces of the Elder Faiths of Ireland", Vols. I & II, (Port Washington, NY: Kennikat Press, 1902)
Published by CultWatch Response, Inc., PO Box 1842, Colorado Springs, CO 80901-1842. This article may be reprinted only if it is not excerpted or abridged in any way except for review purposes. Permission to republish must be requested in writing from the author at the above address. Price: $1.00 each, 10/$8.00, over 100/$0.65 ea., other quantities available. All prices are postpaid.
CAN-CON 2019 - Ottawa's only book oriented Science Fiction Convention! October 18-20, Sheraton Hotel, Ottawa, Canada h
No, not "Funny" - "Informative". LN2 is a very common high-end fogging method. Very expensive and complicated, though, not to mention dangerous. Interesting Products, Inc., out of Chicago, is, as far as I know, the best-known manufacturer of LN2 fogging effects.
But yeah, don't try this at home.
If all the world's a stage, anyone who says they want better lighting spends far too much time in a dark theatre.
Just about every supermarket I've ever been to uses dry ice. Generally in the seafood section; they use it to pack seafood for shipment. Once the seafood arrives however, the store has great big freezers to put it in, so they don't need the ice anymore. In my area (Seattle, Washington) it's 98 cents/pound at the average QFC or Albertsons.
The only difficulty in getting the dry ice is that you need to be 18. They check IDs, generally speaking.
See, dry ice can also be used to make very very loud explosive devices. Take your average two-liter bottle, fill it about 20% of the way with warm water, add a few chunks of dry ice, screw the cap on. When the dry ice hits the warm water, it begins to turn into a gas. Eventually this gas buildup will cause the bottle to explode.
I wonder if dry ice is ever mentioned in the patriot act...
Reinvent the wheel only at either a lower cost, greater effectiveness, or your own personal enrichment and satisfaction.
Isnt a microwave faster..... takes 5mins
Liberty freedom are no1, not dicks in suits.
Where I live, all the Wal-Mart supercenters carry it. And some of the grocery stores, too. Now, if we're talking liquid nitrogen, you can get that locally, too. Just a little less common. And they require that you have an 'approved' container.
A summary of the site is that you can suck cool air into your fog machine and make the fog hug the ground.
Use an ice chest with vents cut in both ends, filled with ice (or dry ice) and place the fog machine inlet close to the outlet of the ice chest.
I don't know if you've just accidentally reversed the steps or not, but let me clarify some aspects of fog machines...
I've never seen a fog machine with an air inlet. I've seen lots of professional fog machines with fluid inputs, though, so that you could run hose through your lighting grids or props and not have to disrupt them if the machine ran out of fog juice (especially in the middle of a show!).
A fog machine works by pumping fog juice into a small heated cavity with a very small exit hole. Usually, the heating cavity is built into a cylindrical rod or pipe. As it's pumped into the confined cavity, the fog juice expands very suddenly, which increases the pressure inside the cavity and causes it to blast out the front of the machine, under great pressure. (150PSI or so, I would think; I've seen fog machines explode their heater assemblies.) Surrounding the heater assembly is generally an insulated box (which *always* gets really gross with leaked fog juice). The insulation is to prevent people from getting burned should they touch it - and to reduce the running time of the heater element inside the heater assembly.
The heater assembly is usually set back sufficiently far inside the nozzle that it's difficult to touch the heater assembly accidentally.
While the concentric shape of the fog machine's nozzle might lead you to believe that there's a system to draw air through the fog machine, I assure you that there isn't.
If you were to create a hole inside an existing fog machine and attempt to pump chilled air through it, I think it's very unlikely that you would manage to make fog which sinks to the ground. More likely, the fog machine's thermostat would detect that the heater assembly was cold, and would keep the heater on longer. The fog would remain at normal operating temperature as it left the nozzle - if not, there will be no fog. Most fog machines will not pump fog juice into their heater assemblies until the thermostat reports that the heater assembly is up to the correct running temperature.
The system works as follows:
[FOG JUICE BOTTLE] --> fog juice --> [FOG MACHINE] --> hot fog --> [CHILLER] --> cool fog --> [STAGE]
Fire and Meat. Yummy.
This is a great idea and I will have to build one for myself the next time I am involved with a haunted house. I just thought I would let you know of an easier method for the lazy people out there. When faced with the problem of floating fog, I also decided on using dry ice to cool the fog, but having a million other problems to solve in my haunted house, I struck upon a very simple solution. Use a piece of PVC pipe that is of the same diameter as the fog machine's output nozzle, and place the dry ice in the PVC. Since the pipe is rather narrow, the fog passes over the dry ice, and if you place the ice along a 2-3 foot segment, it is cooled down very nicely. For best results, use crushed dry ice (larger surface area means better cooling) and check/ re-fill the pipe every hour or so. That is the easiest method, but I do like the slick package they put together with the cooler and all.
There's no point in being grown up if you can't be childish sometimes. -- Dr. Who
I work in theatre and Rosco makes a nifty device called a ColdFlow. I bought one for a show a while back and it basically works like this:
You hook up a Dewar tank of liquid CO2 to this device - it makes dry ice in a tubular cavity with heatsink-like protrusions. When it is properly chilled, you can fire a professional fog machine (like the High End F100 - incredible output) through the chamber and it can cover a stage 50 feet wide and 40 feet deep with ground-hugging fog knee deep. Of course, it's $1200 and the Dewar tank costs $130 and can only be stored for so long, but you can continually chill the ColdFlow for 18 hours off a 400 pound tank. The High End F100 costs about $1000, but if you ever want to create an absolutely ridiculous amount of cold fog - that's your best bet. Talk to your local theatre technicians and ask to play with their toys - they're always happy to oblige (I know I am).
The chiller can be built very inexpensively (major cost is the sacrifice of a largish cooler)
I built one of these for my high school theater. I used a cheaper ($3 - $5) plain Styrofoam cooler. It won't hold up as long as the nice plastic/Styrofoam cooler in the article, but works just as well for the yearly Halloween party.
You're talking about the fogging equiment, right? Liquid nitrogen itself is, as the saying goes, cheaper than beer. It's around US$0.50 a liter... plus dewar rental fees for a container to transport the stuff around.
to dry in the microwave you put it between two pieces of pater towl then microwave for a few minutes. this seems to be quite effective although unlike freezing the liquids are evaporated and while they are mostly absorbed by the paper towel you can smell it in the microwave.