How To Boil Water
Three ways to boil water! Yep three!
Here are three different methods for boiling water with the objective being to kill anything in it so that the water is safe to drink. Filtration can be done to improve the look and the taste.
Method one is familiar one. Put the water in a pot and add heat the water with some sort of a heat source such as a fire. Bring the water to a heavy boil for at least one minute. At sea level this works fine but as you move to higher elevations the water will boil at lower and lower temperature and will need to be boiled longer.
Method two is similar but instead of adding the heat to a pot you instead add a hot rock that has been sitting in a fire. The hot rock will heat up the water to a boil if you don't try to do to much water at one time.
Obviously if you have a pot this method should not be used. But this method works great in survival situations where you have no man made material. The water container could be something as simple as a large leaf or some other natural container that you have made.
The last method is actually similar to the first. Except it can be done with thin paper cups if that is all you have and don't have a pot handy. Crazy as it may sound it does work and here is how.
What temperature does water boil at? 212 degrees F correct (100C)! But what if you add more heat? It still does not ever get above 212 (100C)! That is unless it is in vessel that is air tight. As more heat is added to the container and the water molecules absorb that heat and when they reach 212 degrees they turn to steam. So more heat just makes the water turn to steam faster it doesn't heat the water any higher than 212 degrees.
But how does the cup not catch on fire?
Well it is in direct contact with the 212F (100C) water and does not get much higher than that because the 212 degree water keeps it at that temperature. 212 degrees is not hot enough for the cup to start vaporizing and therefore burn. So what you will see is as the water boils of the water level will drop. Leave the cup long enough and all the water will boil off and as it does the partion of the cup above the waterline will catch fire and burn. But any part of the cup that is below the water line will never catch fire.
Fun to show kids if nothing else and is a good science demonstartion.