Hand Warmers
Well it is winter time again so here is a warm little experiment you can try.
How To Make Hand Warmers:
If you’ve carried a pack along to a game, crammed some into your shoes or boots on a cold day, or taken them hunting.
While there are several types of commercial hand warmers, here are two easy recipes using either rust iron filings to create a warm and toasty, pocket-portable heat source, or using calcium chloride, your choice.
What You Will Need for Iron Recipe:
Iron filings
Sodium chloride (table salt)
Snack size Ziploc bag, or other small size you may have
Quart size Ziploc freezer bag, or other larger size you may have.
Water gel powder (sodium polyacrylate), or other absorbent material, such as sawdust, sand, or vermiculite (clay).
Directions:
Put 30 grams (approximately 1 1/2 tablespoons) iron filings in 3×5 zip-top bag.
Add 1 1/2 tablespoons salt.
Add 1 1/2 tablespoons sodium polyacrylate or other water absorbent material.
Finish with 1 1/2 tablespoons of warm – NOT hot – water.
Carefully remove air and zip bag closed.
Place 3×5 bag inside 4×6 bag. Carefully remove air and zip bag closed.
Shake, squeeze, knead, and thoroughly mix the mixture for 30 seconds or so until a slush forms inside the smaller bag and the water is completely mixed in.
Be careful how you set the bag down, if it gets too hot.
Here Is What Happened:
When you introduce the iron filings to salt, air, and water, it produces iron oxide, or rust. The chemical reaction that occurs is considered an exothermic reaction (produces heat). Since Exo means out and thermal means heat, an exothermic reaction is literally one in which heat (or light) is released. In this experiment, while the oxidation is occurring, heat is produced. The sodium polyacrylate, or water gel powder, helps lock in moisture so the chemical reaction can take place. But once the air-activated process is complete, no more heat will be emitted—this can take from one to several hours!
Note:
To avoid possible exposure to tetanus, throw the hand warmers away when you’re finished experimenting.
If you would like to try some further experimentation here are some variables you can try.
Further exploration:
How does the reaction change if you add more iron filings? How does it change if you add less?
What about the other ingredients?
How does adjusting the ratio of salt or water gel powder affect the reaction?
Repeat the experiment using varying amounts of materials. Use a thermometer to record the temperature of each and and note how long the bag stays heated.
What You Need for Calcium Chloride Recipe:
Calcium chloride (ice-melt pellets)---available at most hardware stores.
Water---available almost everywhere on planet earth.
Two ziploc bags of different sizes (snack size and quart size) .--- available at most stores.
Instructions:
1. Fill a larger ziploc bag one quarter of the way full with calcium chloride ice-melt pellets.
2. Fill a smaller ziploc bag halfway with water, close tight, and place inside the first bag.
3. Squeeze the smaller bag until it breaks open, to create a heat-producing reaction that will last 20 to 60 minutes.
Further exploration:
Adjust the amount of calcium chloride to water ratio.
How does the reaction change in duration if you add more or less?
How does it effect the reaction as far as how to how hot it gets?
How does it affect how long it stays hot for?
As Always do your research, be safe, and enjoy.
Author, John Morgan.
Courtesy of, Preppers Are We