The 5 minute instant hand warmer!

Everybody has seen them, the instant hand warmers sold during the winter months for insane prices. However In this instructable Im going to show you an easy way to make an instant handwarmer with things that you proably have liying around your house!

Its a little odd for me to be posting this in the middle of summer, but in hopes of another stay warm contest I would like to see your feed back to help improve this instructable.

EDIT: BE SAFE
please avoid direct skin contact with the solution! I am by no means a chemist, I do not know how safe this reaction actually is.  I've heard several people say several different things.  Some people claim this produces hydrochloric acid, but I never got burned from touching it.  Whatever is actually happening doesn't matter, please be safe and do not touch the solution or inhale the fumes! Thank you!
EDIT: Published in Popular Science! :D 
http://www.popsci.com/diy/article/2012-02/5-minute-project-hand-warmers

Step 1: Gather the materials

There are only 4 things needed to make the handwarmer, all of them are very easy to aquire, if you dont already have them.
*one large ziploc bag
*one smaller ziploc bag
*some calcium chloride ice melter pellets
*Water

Thats it!


really it is!

Comments

[shannonlove]

The reaction of Calcium Chloride and water is CaCl2 + H2O--> Ca(HO)2 + 2HCl. Which is calcium hydrate and hydrochloric acid.

I am pretty sure they mix some type of base with the Calcium Chloride to react with the hydrochloric acid to turn it into a common table salt (NaCl) and carbon dioxide (CO2). The CO2 is the gas produced.

[Know_CaCl2]

Please note, this is not correct chemistry. An acid and a base cannot co-exist in the same solution. The CaCl2 reacts with the water and releases heat...an exothermic reaction. Calcium Chloride pellets can be purchased under the trademark brand Presone Driveway Heat or Qik Joe at hardware stores, home improvement/big box stores and the like during pre-season and winter months.

[shannonlove]

It's actually fairly common to find dry combinations of acids and bases. The most commonly known would be baking powder which is a combination of sodium bicarbonate (base) with tartaric acid (acid). They do not react until mixed with water. Then they react and produce CO2 used in lea

In this case, however, I was wrong because I neglected that CaCl2 is an ionic compound. When dissolved it goes CaCls-->Ca(2+)aq + 2Cl(1+)aq. The ionic dissolution creates the heat from the energy stored in the bond. 

My chemistry is apparently a bit rusty. Not a lot of call for it in the programming biz.

[heathbar64]

I think I remember that regular old rock salt is calcium chloride. Have you tried using it? I never checked what the little Ice melting pellets are made of, but I know they are way more expensive than regular rock salt.

[Know_CaCl2]

Rock Salt is sodium chloride NaCl2. Calcium chloride is CaCl2. They are two different chemicals. Calcium chloride pellets are exothermic which provides the heat releasing action when exposed to moisture (ice, water, etc.) Rock salt is not exothermic and will not work in this application.

[Fishpail]

I believe that's SODIUM chloride, friend.

[heathbar64]

The way I learned it, table salt is sodium chloride and rock salt is calcium chloride. But then, I'm just a hillbilly.

[Bert99]

ur rite it is

[junits15]

I'm not sure about regulat rock salt, and I havent tested it because I dont have any on hand, but when I get some I might give it a shot

[Fitwit]

ZipLoc bags and the like are NOT water-tight. Plan on leaks.

[ariearie]

Don't leave those bags in the car, hoping you could use it when your get onto a frozen car... when it is freezing outside, the water in the inner zip bag will be ice and it will not work..

[AnaisM]

Is there are specific reason why we should squeeze out the excess of air, or it is just to make it more compact and less likely to burst?

[nintwala]

its probably so that you can break the inside bag instead of the outside cause the air will cause some cushioning.

[junits15]

Just so it doesn't break when you open it

[NatNoBrains]

LOL 5 Minute and instant at the same time!

[ducktape.mac]

i like the idea, but the chlorine stuff, where can you get that? if you can tell me where to get it, i plan on making it!

[junits15]

its ice melter, get it at like lowes or someplace like that but its not the salt kind of ice melter

[ducktape.mac]

is it cheap?

[junits15]

kinda, if you get a little jug

[ducktape.mac]

okay, thanks.

[beehard44]

finally! i am searching ideas for my MRE warmers (i was able to preserve them) and originally thought about 0000 steel wool ground into filings and vinegar.

[Mr Cheeseo]

How hod does it get and for ow long?

[junits15]

The heat output and time is determined by the ammount of CaCl2, simply the mor CaCl2 the more heat and the more time, just becareful not to put too much or you could melt the bag!

[Mr Cheeseo]

A very fine line that deserves some very not so fine experimentation.






























END TRANDMISSION

[kariswg1]

WOW, my wife buys the ready made hand warmers during our cold Michigan winters. I just tried this out and I am going to make some up for her to carry in the car. I will check out thicker bags, because they really get very warm. Thanks again.

[pyroal]

i live in michigan to and this will help when i go hunting

[junits15]

Glad you like it! Try some glad freezer bags they seem to work very well.

[futeng]

Where can I get the calcium chloride? Also, to make this better, I would suggest adding something like a needle to make it easier to pop.

[junits15]

its hard to find them off season, but during the winter they are sold at any lowes or home depot, sometime even grocery stores have them I don't lnow if I would really like to have a needle in something like this, it proably best to use focker's idea.

[kyro159]

where could u get the pellets???

[junits15]

its hard to find them off season, but during the winter they are sold at any lowes or home depot, sometime even grocery stores have them

[Focker]

To pop the small bag, just rub the seal and it should slide itself open.

[junits15]

oh thats a great idea! i be sure to update it!

[turbonegro]

I wouldnt want a needle in my handwarmer