Hand warmer and water bottle
Stormin Mormon
from Walmart. Rip them open, and the iron filings get hot.
I decided to try them on a frozen bottle of water, to see if
they would melt ice to water.
Got a hand warmer pack, and ripped it open. Went to the van,
and brought out a freshly laundered towel. Wrapped the hand
warmer and the 20 ounce bottle, snugly with the towel. Left
the towel wrapped bottle on the front seat of the van.
About two hours later, I came back from the store, and a
couple errands. The hand warmer had not gotten warm, and
there was no change in the bottle. Well, that's some what
less than effective.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
Frank
Engineering News:
For winter sports enthusiasts, hand warmers can mean the difference
between calling it a day early and playing outside for as long as
possible. In fact, anyone who braves cold temperatures might be tempted
to try the little pouches that emit warmth within seconds of being
exposed to air.
Hand warmers date back centuries to when the Japanese would use hot
stones to warm their hands, says Keiko Ishikawa, a marketing manager of
hand-warmer maker Mycoal USA. Portable hand warmers filled with hot ash
were the version that followed, she says.
These days, disposable hand warmers turn up the heat in your mittens by
means of an exothermic reaction that, in essence, just creates rust.
Each pouch typically contains iron powder, salt, water, an absorbent
material, and activated carbon. When the pouch is removed from its outer
packaging, oxygen drifts across the pouch�s permeable covering. With
salt and water present, the oxygen reacts with the iron powder located
inside to form iron oxide (Fe2O3) and release heat.
The absorbent material can be vermiculite, pulverized wood, or a
superabsorbent polymer such as polyacrylate. It helps retain the
moisture so that the reaction can occur. The activated carbon helps to
evenly disperse the heat produced, which can average 135 �F.
Although the chemistry of disposable hand warmers is simple, their
engineering is more complicated. �You want to make this thing act
quickly because people like to open up the packet and feel warm right
away, but you also want it to last a long time,� says Joe Vergona,
manager of engineering and product development for Grabber Performance
Group, a Grand Rapids, Mich.-based company that sells hand warmers. For
example, some hand warmers last seven hours, and others can last more
than 24 hours.
To lengthen the time a hand warmer lasts, some companies opt to increase
the amount of iron in the packet, Vergona says.
Another strategy is to experiment with the iron powder. �If you vary the
raw materials in the warmer, you can change how quickly the reaction
happens or how much of the warmer is reacted at one time,� Vergona adds.
For example, the greater the surface area of the iron, the more it can
react with oxygen to produce heat, he says.
The pouch material also affects the performance of the hand warmers.
�It�s a balance of the ingredients inside the pack and the performance
characteristics of the pouch itself,� Vergona says. The iron powder and
other ingredients are contained in a blended nonwoven material that has
specific permeability characteristics. If the pouch admits more oxygen,
the reaction occurs more quickly. Toe warmers, for example, use a
nonwoven material that lets in more oxygen to compensate for the
low-oxygen environment inside a shoe. �The level of perforation, the
size of the holes�all that�s going to govern how much oxygen enters the
warmer,� Vergona says.
�You want to make this thing act quickly because people like to open up
the packet and feel warm right away.�
To extend the shelf life of hand warmers, the outside wrapper is
specially chosen to ensure that minimal amounts of oxygen get in and
minimal water gets out. �Any old plastic, and the hand warmers will last
a week and die,� because oxygen can get in and spoil the product,
Vergona says. The outside wrappers are usually made of polymers such as
the plastic polyethylene.
The main difference between disposable hand warmers and some reusable
versions is the chemicals used to produce the heat-releasing reaction.
Reusable hand warmers don�t contain iron but instead use a
supersaturated solution of sodium acetate that releases heat as it
crystallizes. Boiling the used packet restores the solution to its
supersaturated state. Air-activated hand warmers can�t be reused.
Besides warming hands and feet, the technology has other applications.
For example, Grabber sells heavy-duty warmers that can be used to
transport tropical fish. The company is also expanding into the medical
and therapeutic fields.
Hand warmers can even be used to teach exothermic reactions, as Kathy
Ceceri, a mom who homeschools her children, discovered. The packaging
instructions might have �said not to open the packet, but I immediately
opened it and poured the contents into a glass jar,� she says, noting
that the iron powder began to smoke. By completely exposing the iron to
air, she accelerated the exothermic reaction.
Ceceri�and anyone else who�s used hand warmers�has discovered that
there�s nothing like simple chemistry to help turn up the heat.
Stormin Mormon
to air. I mashed and shook the packet. Started, slowly, to
get barely warm. Totally not warm enough to melt a bottle of
ice. I guess that technique isn't going to work. At least,
not with this particular warmer.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"Stormin Mormon" <cayoung61**spamblock##@hotmail.com> wrote
in message news:hk2fba$l0m$1...@news.eternal-september.org...
greylock
Bad heat pack............?????
My experience is with some that are WAAAAY out of date and are wrapped
in a pretty heavy - sorta clear - plastic material, but seem to
always work so far as I can remember.
I bought a box (case???) of them years ago at a garage sale, so I have
no idea what store they may have sold in.
If anything they get a bit TOO hot, you really cannot tolerate them
against your skin for very long at a time. they work best for me if I
keep them in a pocket and slip my hand in, off and on. On one
memorably bitter and windy deer stand, I slipped some into the back of
my gloves and the top of my socks above my boots. I was cold enough
that time that they stayed until I was off the stand. They typically
stay warm for six to either hours.
I think your idea might be good - but perhaps your choice of materials
is not be up to it.
Frank
I would only buy those wrapped in plastic with metal foil. Metal will
keep out oxygen but eventually enough will permeate pure plastic to
oxidize the iron. To preserve opened ones for a short period, wrap in
Saran but for longer periods use aluminum foil.
Hunting, I use like you do. First, I shake the warmer then blow breath
into it to get some moisture as the iron rusts faster with moisture.
Exclude air and moisture and heat generation is slow.
hal
wrote:
>Bad heat pack............?????
>
>My experience is with some that are WAAAAY out of date and are wrapped
>in a pretty heavy - sorta clear - plastic material, but seem to
>always work so far as I can remember.
>
>I bought a box (case???) of them years ago at a garage sale, so I have
>no idea what store they may have sold in.
>
>If anything they get a bit TOO hot, you really cannot tolerate them
>against your skin for very long at a time. they work best for me if I
>keep them in a pocket and slip my hand in, off and on. On one
>memorably bitter and windy deer stand, I slipped some into the back of
>my gloves and the top of my socks above my boots. I was cold enough
>that time that they stayed until I was off the stand. They typically
>stay warm for six to either hours.
>
>I think your idea might be good - but perhaps your choice of materials
>is not be up to it.
It is a simple calculation to figure out how many hand warmers it
takes to melt ice. It takes 144 btus to convert a pound of ice to a
pound of water at 32deg. I'm sure the manufacturers of various heat
packs have the information on number of btus generated. You don't
have to waste hand warmers to figure out what you can look up in a few
minutes.
None4U
<hal> wrote in message news:4b65e0ac...@news.newsguy.com...
Ive had some go bad too. But they definately got their uses. I usae them
in my boots deer hunting. And in my socks when camping in the snow. The
longer lasting ones burn cooler, and the shorter lasting ones are hotter.
But I get the biggest ones . Ive never tried to heat anything like water
with them I cant see it happening at all. It would be easier to put the end
of a light bulb in the cup.
Retief
<cayoung61**spamblock##@hotmail.com> wrote:
>Some weeks ago, got some of the foil packed hand warmers
>from Walmart. Rip them open, and the iron filings get hot.
>I decided to try them on a frozen bottle of water, to see if
>they would melt ice to water.
Why?
OK, you're travelling in the winter, have no car, and want to melt
water without stopping to build a fire... (is this the correct
scenario?)
You get one of these, and string it to hang inside your coat, outside
of your inner clothing:
http://www.trailspace.com/gear/nalgene/wide-mouth-cantene-96-oz/
Fill it with snow/ice, and wait for it to melt.
In the meanwhile, also keep your other water bottles inside your coat
to prevent freezing (it is easier to maintain liquid water, than to
re-create it once frozen)...
>About two hours later, I came back from the store, and a
>couple errands. The hand warmer had not gotten warm, and
>there was no change in the bottle. Well, that's some what
>less than effective.
These produce similar heat, at a lower price:
http://www.cabelas.com/p-0006823512886a.shtml
(I bought some knock-offs for something like $5, that recommend using
white gas -- so $5 for the hand warmer, $5 for a gallon of fuel...)
Retief
Stormin Mormon
>Some weeks ago, got some of the foil packed hand warmers
>from Walmart. Rip them open, and the iron filings get hot.
>I decided to try them on a frozen bottle of water, to see
>if
>they would melt ice to water.
Why?
CY: Becuase water bottles left in the car (in winter)
freeze. I can imagine having a frozen water bottle, and
wishing it were not frozen.
OK, you're travelling in the winter, have no car, and want
to melt
water without stopping to build a fire... (is this the
correct
scenario?)
CY: It is one scenario, but not the one for the hand warmer
test,
You get one of these, and string it to hang inside your
coat, outside
of your inner clothing:
http://www.trailspace.com/gear/nalgene/wide-mouth-cantene-96-oz/
Fill it with snow/ice, and wait for it to melt.
CY: Of coure, that's one option.
In the meanwhile, also keep your other water bottles inside
your coat
to prevent freezing (it is easier to maintain liquid water,
than to
re-create it once frozen)...
>About two hours later, I came back from the store, and a
>couple errands. The hand warmer had not gotten warm, and
>there was no change in the bottle. Well, that's some what
>less than effective.
These produce similar heat, at a lower price:
http://www.cabelas.com/p-0006823512886a.shtml
CY: I'll have to look.
robert bowman
> CY: Becuase water bottles left in the car (in winter)
> freeze. I can imagine having a frozen water bottle, and
> wishing it were not frozen.
That is a problem. I've got a Platypus in my pack in the car. Sometimes it's
frozen, sometimes not. For that matter, the water bottle on my gym bag
sometimes freezes if I leave the bag in the car at work. Ballpoint pens
freeze, too.
Stormin Mormon
bottles on the defroster, with the heat blowing on the
bottles. I'd forgotten ball pens, though it makes sense, now
you mention it.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"robert bowman" <bow...@montana.com> wrote in message
news:7tel59...@mid.individual.net...
Retief
<cayoung61**spamblock##@hotmail.com> wrote:
>>Some weeks ago, got some of the foil packed hand warmers
>>from Walmart. Rip them open, and the iron filings get hot.
>>I decided to try them on a frozen bottle of water, to see
>>if they would melt ice to water.
>
>Why?
>
>CY: Becuase water bottles left in the car (in winter)
>freeze. I can imagine having a frozen water bottle, and
>wishing it were not frozen.
Still not the best solution. If your car is running, figure out how
to use the battery power (or heater system) to thaw your water.
It could be a simple as finding a container that is conducive to being
placed on the exhaust manifold for heat.
Or pull power from the cigarette lighter.
If you are without your car (though you are with your car, and thus
your frozen water bottles from your car), instead start a fire and
melt the water, then prevent it by re-freezing by the methods
described.
>OK, you're travelling in the winter, have no car, and want
>to melt
>water without stopping to build a fire... (is this the
>correct scenario?)
>
>CY: It is one scenario, but not the one for the hand warmer
>test,
So you discovered your water bottle frozen on your person, despite
your having been carrying it all day?
I'm puzzled as to your scenario.
If you are without liquid water, the standard method is that you start
a fire and melt it. Once you have it thawed, you prevent it from
freezing again (by keeping it in a "cooler", or keeping it inside your
coat or sleeping bag).
If you aren't in a hurry for liquid water, you once again place the
bottle inside your coat, allowing your body's waste heat to melt it.
You're apparently telling me that you started off with a frozen
bottle, ignoring rule #1 -- to melt the water so you have liquid
water, and/or rule #2 -- don't let it freeze again.
How did you come to this terrible situation? Do you even have clothes
on your back? Why did you start out with a frozen bottle? Why do you
have no equipment to start a fire, or melt snow? It sounds like
you're pretty screwed...you started without engaging your brain.
Did I mention that I just recently got back from my annual winter
excursion? I carried a metal water bottle, so I could sit it near the
fire without fear of it melting. I carried plastic bottles to hang
inside my coat.
>You get one of these, and string it to hang inside your
>coat, outside of your inner clothing:
>http://www.trailspace.com/gear/nalgene/wide-mouth-cantene-96-oz/
>
>Fill it with snow/ice, and wait for it to melt.
>
>CY: Of coure, that's one option.
Your body, when resting, puts out something on the order of 100 watts.
That waste heat is very useful. Use it. Don't waste a valuable hand
warmer, which might be relevant to your survival, on a silly operation
such as melting your water bottle.
Instead, take your hand warmer and place it in your shirt pocket,
inside your coat.
>These produce similar heat, at a lower price:
>http://www.cabelas.com/p-0006823512886a.shtml
>
>CY: I'll have to look.
The old hand warmers I own worked well on standard lighter fluid.
The newer hand warmers I bought were rather fussy, and did not stay
lit with standard lighter fluid (the packaging said to use "white gas"
-- which typically is very similar to lighter fluid, naptha, but not
necessarily identical). They did work with Coleman fuel (though it's
possible that they simply needed a "burn in" with some decent, clean
fuel -- I'll test that later)
As I already mentioned, the heat output seemed to be quite similar to
the iron-air hand warmers (it was my first time using these).
Instead of screwing around, why don't you make one of these?
http://www.instructables.com/id/Can-Stove/
Retief
Retief
wrote:
>That is a problem. I've got a Platypus in my pack in the car. Sometimes it's
>frozen, sometimes not. For that matter, the water bottle on my gym bag
>sometimes freezes if I leave the bag in the car at work.
Try filling it with warm water, and storing it in a small cooler to
reduce the heat load (cooling load) on it.
>Ballpoint pens freeze, too.
That's why I suggested a felt marker (I find they tend to write, when
ballpoints are frozen).
Retief
Retief
<cayoung61**spamblock##@hotmail.com> wrote:
>If I notice early in the trip, I've been able to thaw water
>bottles on the defroster, with the heat blowing on the
>bottles.
Pick the right material and you can heat them on the manifold.
Retief