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#1
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Reusable Heat Packs - Neat.
Ok, after a quick search on the web I find I'm probably *way* behind on
knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary |
#2
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Reusable Heat Packs - Neat.
I have had several of the hand sized packs for maybe 10 years. Still work.
Keep them in the snow ski bag. Once in a while one is hard (triggered on it's own) so just boil or microwave (I boil mine normally as easy to over microwave) and it is good as new. Bill "Gary Warner" wrote in message ... Ok, after a quick search on the web I find I'm probably *way* behind on knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary |
#3
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Reusable Heat Packs - Neat.
Gary,
I used to use one for diving in cold waters. More than likely *much* larger than what you're referring to. And yes, they really do work well. I don't know about creative uses, but they certainly work well when inserted in a wetsuit. You do 'recharge' these in boiling water, but if I remember correctly, it took at least 20 minutes of boiling to convert all the crystals back to a liquid. This is probably more dependent on size. I got mine probably 10 years ago so they have been out a while. One thing I do remember is that you do NOT want to leave these directly against the skin for a prolonged period of time. Mine came in a neoprene pouch. They do produce a lot of heat and some divers have been known to get burned by attempting to dive with the bare pack. However, when you're diving in cold water ( 40 degress +/-), with a wetsuit instead of a drysuit, you tend to want as much heat as possible. As a result, some divers would remove them from the neoprene pouch and place directly against their skin. Not more than once though. :^) -JimL Gary Warner wrote: Ok, after a quick search on the web I find I'm probably *way* behind on knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary |
#4
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Reusable Heat Packs - Neat.
"Gary Warner" wrote in message ... Ok, after a quick search on the web I find I'm probably *way* behind on knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary Welcome to the 90's Gary. Seriously, I wish someone could explain how snapping a little metal disk causes the liquid to crystallize like that. My kids ruined all the ones I've ever had micro-waving them too much instead of boiling. db |
#5
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Reusable Heat Packs - Neat.
Don ßailey wrote:
Seriously, I wish someone could explain how snapping a little metal disk causes the liquid to crystallize like that. The sodium acetate contained in the bag is a "supercooled" liquid. That is, at room temperatures it is below the temperature it would normally change state back to a solid. The click of that little metal disk provides just enough energy to trigger "freezing" by raising the temperature of a molecule or two back up to the freezing point and those first few crystals of frozen material release their heat of fusion to a few more molecules and the process continues until all of the contents are frozen. The heat that is released is the heat that was put into the solid to melt it. The melting point of sodium acetate is around 130 degrees F and that is about the temperature you can expect the bag to reach. Rick |
#6
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Reusable Heat Packs - Neat.
Jim, Diving with them is a great idea. I didnt' go at all this year... too busy and too broke working on the boat...but maybe next year. I can imagine those getting hot next to your skin, escially as you dive down the the pressure increases - pushing it into you. But with a pouch or hand-towel or something "JimL" wrote in message ... Gary, I used to use one for diving in cold waters. More than likely *much* larger than what you're referring to. And yes, they really do work well. I don't know about creative uses, but they certainly work well when inserted in a wetsuit. You do 'recharge' these in boiling water, but if I remember correctly, it took at least 20 minutes of boiling to convert all the crystals back to a liquid. This is probably more dependent on size. I got mine probably 10 years ago so they have been out a while. One thing I do remember is that you do NOT want to leave these directly against the skin for a prolonged period of time. Mine came in a neoprene pouch. They do produce a lot of heat and some divers have been known to get burned by attempting to dive with the bare pack. However, when you're diving in cold water ( 40 degress +/-), with a wetsuit instead of a drysuit, you tend to want as much heat as possible. As a result, some divers would remove them from the neoprene pouch and place directly against their skin. Not more than once though. :^) -JimL Gary Warner wrote: Ok, after a quick search on the web I find I'm probably *way* behind on knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary |
#7
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Reusable Heat Packs - Neat.
Sure. You're way-way behind.
JR Gary Warner wrote: Ok, after a quick search on the web I find I'm probably *way* behind on knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary -- Remove X to reply -------------------------------------------------------------- Home Page: http://www.seanet.com/~jasonrnorth |
#8
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Reusable Heat Packs - Neat.
Hi Gary,
I was at "The Coleman Store" a year or so ago, and noticed warmer packs that you simply tear open and they heat up. On impulse, I bought a dozen, and boy do they work good. One .99 pack will heat like heck for 6-7 hours. The store also has propane powered catalytic "golf cart" heaters. This worked well for my bridge as they are designed to mount to a cup holder. (I have reverse cycle H&AC in the cabin) Last winter, the few cold days we had were made quite comfortable by the little unit. I would not consider its use in an unvented cabin or near fuel system components. Regards, Capt. Frank Hopkins http://www.home.earthlink.net/~aartworks Gary Warner wrote: Ok, after a quick search on the web I find I'm probably *way* behind on knowing about these. but anyway.... Was in a mall the other day and being sold at a kiosk was a reusable heat pack. Permanently sealed, when you "snap" a metal disk in the pack's liquid, the liquid crystallizes and releases heat. The sales-kid (and web reports) say the heat will last for 45 minutes or more. The part that's really great is you can reverse the process by boiling the bags in hot water - ready to be reused. Seems to me this could be very handy for those cold boating days or possibly even in a ditch bag. Anyone use these and have comments and/or creative uses? Hmmm, maybe someone could market little *cold* ones shaped like ice cubes - never know when occasion for a cocktail might arise. Gary |
#9
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Reusable Heat Packs - Neat.
The store also has propane powered catalytic "golf cart"
heaters. This was a Coleman product? They're small enough to fit in a cupholder? This would be good for my cockpit. |
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