I just bought some icewater bottles for my knees after exercising. I use two per knee. I used to use 1 quart plastic food storage bags, three bags inside each other and tied off with twine to prevent leaks, but it became too cumbersome.
The icewater bags have a screwcap which only allows you to put one ice cube in at a time. This takes time for four icebags, two ice trays per bag-I like my icewater cold.
The various wraps and bags with blue glop they sell for this purpose I find unsatisfactory. Only ice water does the trick for me.
The icebags are fabric treated with an internal coating of latex.
There are trays which make smaller icecubes, as well as icemakers which make small cubes, but I decided to try something different.
Instead of adding icecubes, I decided to try adding some kind of additive to the water in the bags to prevent freezing and keep them in the freezer, removing them only when treating my knees. I realize that this will likely make the bags too cold to contact the skin, but I figure dunking them in a 10 gallon bucket of room temperature water for a few minutes will warm them up to the point they will be cold, but suitable for use on the skin.
I was considering salt as an additive, but I read somewhere that latex reacts badly with salt. I was considering ethylene or propylene glycol, but it also said that latex does not like solvents or petroleum products or much of anything else, apparently. I don't know if the glycols are either of these, but I suspect they might be.
The icebag manufacturer is little help, they tell you to put water or ice and nothing else in there.
Researching on the net, I read that sugar and gelatin dissolve in water but are non-ionizing, which I presume means non corrosive as well. I mean, acids and alkalis and salts of same are highly ionizing, and latex doesn't like those, so latex probably doesn't mind nonionized solvents, right?
So I got some sugar and pure, nonsweetend gelatin, and I wonder if anybody can tell me how much gelatin or how much sugar I should use in four quarts of water to prevent freezing when the freezer goes down to plus 15 deg Fahrenheit. I am leaning toward gelatin because latex is the sap of a plant and I suspect there might be some form of sugar in it which might react with the table sugar I am putting in the water. After all, there's plenty of sugar in the sap of a maple tree, why not at least a little sugar in the sap of a rubber plant?
Anybody with knowledge or experience in the chemical field or working with these materials?
Thanks.
The icewater bags have a screwcap which only allows you to put one ice cube in at a time. This takes time for four icebags, two ice trays per bag-I like my icewater cold.
The various wraps and bags with blue glop they sell for this purpose I find unsatisfactory. Only ice water does the trick for me.
The icebags are fabric treated with an internal coating of latex.
There are trays which make smaller icecubes, as well as icemakers which make small cubes, but I decided to try something different.
Instead of adding icecubes, I decided to try adding some kind of additive to the water in the bags to prevent freezing and keep them in the freezer, removing them only when treating my knees. I realize that this will likely make the bags too cold to contact the skin, but I figure dunking them in a 10 gallon bucket of room temperature water for a few minutes will warm them up to the point they will be cold, but suitable for use on the skin.
I was considering salt as an additive, but I read somewhere that latex reacts badly with salt. I was considering ethylene or propylene glycol, but it also said that latex does not like solvents or petroleum products or much of anything else, apparently. I don't know if the glycols are either of these, but I suspect they might be.
The icebag manufacturer is little help, they tell you to put water or ice and nothing else in there.
Researching on the net, I read that sugar and gelatin dissolve in water but are non-ionizing, which I presume means non corrosive as well. I mean, acids and alkalis and salts of same are highly ionizing, and latex doesn't like those, so latex probably doesn't mind nonionized solvents, right?
So I got some sugar and pure, nonsweetend gelatin, and I wonder if anybody can tell me how much gelatin or how much sugar I should use in four quarts of water to prevent freezing when the freezer goes down to plus 15 deg Fahrenheit. I am leaning toward gelatin because latex is the sap of a plant and I suspect there might be some form of sugar in it which might react with the table sugar I am putting in the water. After all, there's plenty of sugar in the sap of a maple tree, why not at least a little sugar in the sap of a rubber plant?
Anybody with knowledge or experience in the chemical field or working with these materials?
Thanks.
Well, for water, k = 1.8 degrees C/mol. Salt gives two moles of ions for each mole of salt. You want to depress the freezing point about 17 degrees F which is about 9.5 degrees C.
FPD = m * k. Rearranging, m = FPD/k = 9.5/1.8 = 5.3 moles/liter. You've got about 4 liters, so you need about 22 moles of ions, which corresponds to 11 moles of salt. The molecular weight of salt is about 58 g/mole, so the mass needed is 58 * 11 = 638 g.
FPD = m * k. Rearranging, m = FPD/k = 9.5/1.8 = 5.3 moles/liter. You've got about 4 liters, so you need about 22 moles of ions, which corresponds to 11 moles of salt. The molecular weight of salt is about 58 g/mole, so the mass needed is 58 * 11 = 638 g.
poobah said:
Poobah:
So you are saying that if I put two pounds of ice in cold water, and one pound of it melts while I have it on my knee, I will be drawing many times more heat out of the knee, (blood and tissues) than if I put a similar amount of cold salt water at the same temp on the knee?
Or, in other words, "stick with the ice water"?
Poobah:
Wait. Are you saying that the saltwater draws the same amount of heat out of the knee as pure ice in pure water after all, because of the different characteristics of saltwater from ice water?
Keeping everything liquid is more convenient, but if it is better for the knee to add ice to pure water, I can do that. There are ways to get smaller ice cubes that pour into the icewater bag.
Wait. Are you saying that the saltwater draws the same amount of heat out of the knee as pure ice in pure water after all, because of the different characteristics of saltwater from ice water?
Keeping everything liquid is more convenient, but if it is better for the knee to add ice to pure water, I can do that. There are ways to get smaller ice cubes that pour into the icewater bag.
Depends how long I keep it on.
I used to use it years ago back when I was jogging. I used three quart food storage plastic bags stuffed inside each other to prevent leakage, tied off with twine, each with two trays of ice each bag plus cold water from the tap to cover the ice.
My method was to jog, make the ice water bags, then go into the bedroom, plop down on the bed and watch TV with the ice bags on. I kept a small bucket on the side of the bed to put the ice bags in when I was done.
Since I was watching TV anyway, I really didn't mind the icebags on the knee. I kept them on twenty minutes minimum, in which case a substantial proportion of the ice was melted-perhaps half.
Sometimes I kept them on for forty minutes or more, since the system I had was so convenient. In which case, just about all the ice was melted at the end, although the water still felt very, very cold.
I used to use it years ago back when I was jogging. I used three quart food storage plastic bags stuffed inside each other to prevent leakage, tied off with twine, each with two trays of ice each bag plus cold water from the tap to cover the ice.
My method was to jog, make the ice water bags, then go into the bedroom, plop down on the bed and watch TV with the ice bags on. I kept a small bucket on the side of the bed to put the ice bags in when I was done.
Since I was watching TV anyway, I really didn't mind the icebags on the knee. I kept them on twenty minutes minimum, in which case a substantial proportion of the ice was melted-perhaps half.
Sometimes I kept them on for forty minutes or more, since the system I had was so convenient. In which case, just about all the ice was melted at the end, although the water still felt very, very cold.
Keltic,
I cannot find a good set of values for the heat capacity of saltwater... adding salt does lower the heat capacity of water... but at the same same increases it density... the two factors cancel somewhat. I am finding stuff on seawater... but I don't think that is the concentration that SY is talking about...
What it all means is that gool ole' water and ice might remain your best trick.
But try the saltwater thing... you should observe that it starts gaining in temperature immediately and losses it "cold" about 50 times faster than 50/50 mix of water and ice... all other things being equal of course.
Thought about riding a bike? Easier on the knees I think.
I cannot find a good set of values for the heat capacity of saltwater... adding salt does lower the heat capacity of water... but at the same same increases it density... the two factors cancel somewhat. I am finding stuff on seawater... but I don't think that is the concentration that SY is talking about...
What it all means is that gool ole' water and ice might remain your best trick.
But try the saltwater thing... you should observe that it starts gaining in temperature immediately and losses it "cold" about 50 times faster than 50/50 mix of water and ice... all other things being equal of course.
Thought about riding a bike? Easier on the knees I think.
I thought the question was about an equivalent to an ice packs. Ice packs are cool because they maintain a tolerable temperature... 32F, and they have a huge heat capacity... meaning they can maintain this 32F thing for awhile.
Model away fearless leader... just start with a body that needs a constant flow of heat out in order to maintain a colder temperature... so the knee should be modeled as a resistor with constant power input... not a cap. You will have to model the heat of fusion as a near infinite capacitor... at least until it "melts".
Key desirable features:
* Constant temperature (heat of fusion is beauty here)
* Long lasting (heat of fusion is again beauty)
* Less fillling
* Tastes great
* Costs less than $153 a bottle... even if you are more than 50 lbs. overweight.
Model away fearless leader... just start with a body that needs a constant flow of heat out in order to maintain a colder temperature... so the knee should be modeled as a resistor with constant power input... not a cap. You will have to model the heat of fusion as a near infinite capacitor... at least until it "melts".
Key desirable features:
* Constant temperature (heat of fusion is beauty here)
* Long lasting (heat of fusion is again beauty)
* Less fillling
* Tastes great
* Costs less than $153 a bottle... even if you are more than 50 lbs. overweight.
poobah said:
Is that good or bad, kneewise? I'm getting a hard time understanding this heat capacity vs temperature thing.
poobah said:Thought about riding a bike? Easier on the knees I think.
Actually, the stationary bike is part of the reason I went to commercially produced icewater bags from the homemade system I had been using.
The reason I am giving up the food storage bags is that I walk and also have begun to ride a stationary bike, and the bike causes strain on the upper kneecap and above, while walking and general movement seems to put strain on the lower kneecap and below. Hence, instead of one icewater bag per leg, I now require two per leg, and that requires way too much preparation using the food storage bags and twine.
I have looked around at the thought of smaller ice cubes capable of being poured quickly into the icewater packs.
Icemakers which make smaller than standard cubes are available for $200 or slightly under. Higher than I wanted, but affordable if all else fails.
Then there are ice cube trays which make smaller ice cubes. These are not available in the normal stores, but might be at specialty stores and surely on the internet.
Camco makes smaller trays with smaller cubes for RV's. Even though the ice tray is slightly slimmer than the standard, (4 inches vs 4.5 inches), note the cubes are three across, not two across. Therefore, the cubes will be considerably smaller than the standard.
An externally hosted image should be here but it was not working when we last tested it.
And Kitchenworks has some trays that make 90 really small cubes, which look fun to try regardless of the icebag situation.
So if the ice and water thing really is the way to go, I have options. The "take 'em out of the freezer and slap 'em on" approach is more convenient, though, if it can be managed.
Keltic,
Before my keyboard breathalyzer interlock kicks in... maybe it's time you resolved your plight as I have done. Like a true Kelt, drink, fight, and abandon this exercise baloney. A decent fight will leave your knees the least of your worries. Drinking will ease the pain and curb the impulse to exercise in the first place.
It's win-win thing really...
And yes, barring SY's impending (hopefully) non-molic explanation, I think the little ice cubes are the solution.
NOTE: I think SY, being the chef that he is, averted dancing and thus avoided ever icing a knee... he may not know how fast the bags get warm and useless.
Before my keyboard breathalyzer interlock kicks in... maybe it's time you resolved your plight as I have done. Like a true Kelt, drink, fight, and abandon this exercise baloney. A decent fight will leave your knees the least of your worries. Drinking will ease the pain and curb the impulse to exercise in the first place.
It's win-win thing really...
And yes, barring SY's impending (hopefully) non-molic explanation, I think the little ice cubes are the solution.
NOTE: I think SY, being the chef that he is, averted dancing and thus avoided ever icing a knee... he may not know how fast the bags get warm and useless.
kelticwizard said:
Try rowing - better exercise and easier on the body (note that I don't say easy, just easier).
If you want to put large cubes into a waterproof plastic bag, kayak supply stores will sell you drybags, which can be had with a large mouth (no comparisons, please) which has a watertight seal.
Aengus
Try rowing - better exercise and easier on the body (note that I don't say easy, just easier).
If you want to put large cubes into a waterproof plastic bag, kayak supply stores will sell you drybags, which can be had with a large mouth (no comparisons, please) which has a watertight seal.
Aengus
Poobah:
Emotionally, I am drawn to your solution.
Unfortunately, there is this little thing called blood pressure which rises alarmingly with weight. A continutation of my habits along the lines you indicated are turning my aorta into a potential WMD.....
Haven't had any heart problems yet, but at this rate......
Emotionally, I am drawn to your solution.
Unfortunately, there is this little thing called blood pressure which rises alarmingly with weight. A continutation of my habits along the lines you indicated are turning my aorta into a potential WMD.....
Haven't had any heart problems yet, but at this rate......
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.