jpexg@mit-hermes.ARPA (John Purbrick) (10/12/85)
> > I would like to make one of those fog machines for > > halloween.... I worked on a show once ("Ruddigore") where I was responsible for generating fog at six different locations simultaneously. What I did was this: Get a styrofoam picnic cooler. Cut two holes about 4 inches in diameter in the lid. Fill it half full with water from the hot tap. It will stay hot for a fair amount of time, being styrofoam. Obtain a computer-cooling fan (often called a "muffin fan" or "boxer fan". Then get about a pound of dry ice, put it in a tray and break it up with a hammer so it's in pieces 1 inch or so in size (big pieces-->small amount of fog for long time, small ones-->much fog briefly); if you need to store the broken dry ice, put it in a styrofoam bowl with another bowl inverted over it. Then, when ready to roll, dump the dry ice into the water, put the lid on the cooler and put the fan over one of the holes, blowing into the cooler. Fog will then gush out of the other hole. The fog output will drop off after a few minutes as the dry ice vaporizes and the water cools down--I suppose you could use a metal container on a hotplate to keep the water continuously hot.
mahler@pur-ee.UUCP (Steve Mahler) (10/15/85)
I believe that mineral oil is used in some situations, was it something to do with moisture content differences (of the fog) ? .... Steve