Dry Ice is frozen carbon dioxide (C02 at -109.3 ° F) opposed to regular ice which is 32° F. Unlike regular ice, Dry Ice doesn't melt - it sublimates, the process of going directly from a solid to a gas. Dry ice can be used many ways for Halloween but always use with caution! It can cause very bad freeze burns which are very painful and can permanently damage skin.

For most people the equipment needed to manufacture their own dry-ice is simply too expensive. Dry ice can be found at most Ice Suppliers and Ice Cream shops and isn't that costly. We pay about .75 cents per pound at a local ice supplier. It's much easier to buy than to make but we just thought you might like to know how it's made anyway so here goes. The first step in making Dry Ice is to turn the carbon dioxide gas into a liquid. This is done by compressing the C02 and removing any excess heat. The C02 will liquefy at a pressure of approximately 870 pounds per square inch. Next, the pressure is reduced over the liquid carbon dioxide by sending it through an expansion valve. Part of the liquid sublimates, causing the remainder to freeze into snow flakes. The Dry Ice snow is then compacted together under a large press to form blocks.

Dry Ice will sublimate (change from a solid to a gas) at a rate of 10 pounds every 24-hours in a standard insulated container. The more Dry Ice you have stored in the container, the longer it will last. This means it's important to pick up your Dry Ice as close as possible to the time you will need it. It should be stored in an insulated container like an ice chest to slow the sublimation rate. Refrain from opening and closing the insulated container as much as possible. When you remove items from the container fill the empty space with wadded newspaper. Any "dead-air-space" will cause the Dry Ice to sublimate faster. Do not store Dry Ice in your refrigerator freezer. The extremely cold temperature could cause your thermostat to turn off your freezer.

FOG MAKING WITH DRY ICE

To make fog from dry-ice you simply add pieces of dry-ice to very hot water. One gallon of hot water for every 1 - 2 pounds of dry ice is one formula. The variables of fog generation are the water temperature, amount of the dry ice and the size of the dry ice being used. The smaller the size of dry ice pieces the more fog, the higher temperature of the water the more fog. When the water temperature gets below 40° F, fog production will stop and you will need to change the water. But be warned, it takes a lot of dry ice to produce the same quantities of fog as a small fog machine.

One way to make a very simple dry-ice fog generator is to use a Crock Pot as the heating tank. This works great for placement behind a tree, headstone, crypt, etc. Unless you have a Crock Pot that just happens to be black or other dark color that will make it easily cancelable, you'll need to paint it black. Start by cleaning the surface of the Crock Pot so that the paint will stick. Remove the ceramic cooking pot and selector switch. Mask off the heat control indicator with masking tape. Now spray the Crock Pot. Once the paint has dried thoroughly, put the cooking liner back in. Do not try to use this without the liner in. Doing so could cause electric shock and/or a fire hazard. We use a metal deep-fry basket to hold the dry-ice. While this method does work and will extend the time the water stays hot, the heating element in most Crock Pots are not designed to get that hot, so you will still have to replenish your hot water, although not as often.

MISTING PUMPKIN

This is a very cool looking effect!! After carving your pumpkin or using a foam one, use a light stick or battery powered light inside for internal illumination (never use an AC powered light). Place a clear plastic container with hot water inside and add dry-ice. You cannot use a real candle as the carbon dioxide will extinguish it.