I was thinking about what Blast was saying about getting enough ice early, before a storm. We have a large chest cooler with all of our frozen food in it, and a generator to keep it going during a power outage. But if something happened -- freezer break, run out of gas, etc. -- to keep things cold we'd have to rely on the "don't open the door, fill all empty space with ice" rules.

So I was thinking, dry ice would be better. The local Safeway has a dry ice cooler and they sell it by the pound. Normally it looks like no one goes near it for long periods of time, but I can imagine the stock goes quick before a storm.

What are the problems with keeping a CO2 cylinder, a nozzle and some burlap bags just in case? I understand you can make your own dry ice by sticking the nozzle attached to the cylinder into an empty burlap bag and spraying away. About 46% of the CO2's volume will turn into dry ice snow in the bag, and the rest dissipates into the air. (Do this outside!) Then packing the snow in the bags on top of your food in the chest freezer to keep things cold. Depending on how tightly packed it is, and what its wrapped in, you'll lose 4-5lbs/24 hours. (Info from dryiceinfo.com.)

What the site doesn't say -- is it expensive to keep a CO2 cylinder and nozzle in your garage, say? How long would it last without needing maintenance or topping off? Am I completely nuts in being curious about it?

Another example at http://scientificsonline.com/product.asp?pn=3071533&bhcd2=1222911792.