A different idea and the hunted

[m2b]

Just this reminder for anyone that has nice weather tonight. This is the full moon, the perigee moon, err closest moon of the year and the biggest/brightest moon of the year. I just got back from 15 minutes or so of diving under the full moon, a rather unusual evening in many respects. Yes, the October full moon is known as the Hunter Moon. Who can kill the biggest fish on the night of the Hunter Moon, HA!! Did I just start something, LMAO!!!

Over this past weekend I saw in the equipment/wetsuit forum a posting about hotsuits, err putting sodium acetate heat packs in your wetsuit to act as reuseable heat packs. I did a little playing around online and then on the stove trying to convert baking soda and vinegar into sodium acetate and than add the water to give the same compound that they are using in the real hotsuit heat packs. It didn't work quite as hoped for. Granted if I had actual sodium acetate versus the homemade stuff it probably would have worked better. A true measuring system would probably help as well instead of just guessing how much of each ingredient I was going to be mixing together.

A day or two ago I got to thinking about trying to find some fluid/solid that might have better heat retention than water, no luck thus far. Tonight I decided just for the giggles of it to try and see how well it would work to heat up water in the microwave and put it into ziplock sandwich bags and than tape them to my thermal long john top. I notice Tuesday evening when heading into the water my biggest problem area is when the water gets up to my nipples, then I notice the cold and start to "hyperventilate" until I get use to the colder water. I dive in a tank top style, I believe 3mm, wetsuit so their are no sleeves which leave the entire upper body quite vulnerable to the cold 58-60 degree F water or, in tonights case, the 42-45 degree F air temperature. This did seem to nullify the effect of the nipples hitting the water, no big deal whatsoever at anypoint during the session. Instead tonight I noticed it mostly when the arms got wet, not so much so the underarms but just the arms in general. I found myself wishing/thinking about a way that I could tape a few more hot ziplock bags to my arms to keep them warm as well.

Right now I'm thinking of trying to use freezer bags or just flat out go for a hot water bottle to get one bag/bottle to cover more surface area right from the start. I'm also thinking about taping aluminum foil to the outside of bag/bottle to help reflect any heat back into the container. The bag was pretty much cooled down by the time I got out of the water. I did wear the bag from home to the lake and than for roughly 20 minutes in the water, so I had it on for over half an hour. I didn't take the water up to boiling, I knew better than that. I was definitely keeping the chest warm on the 10-15 minute drive to the lake. I did squeeze essentially all the air out of the bag to try to keep it from acting like more bouyancy but I still did notice something unusual. I was having a harder time than normal going down. I'm not sure if it was related to the dark conditions/my visual perception or possibly extra bouyancy caused by the hot water packs. All the rest of the equipment remained unchanged.

Has anyone else ever tried something similiar to my crazy hot water bag idea and got the heat to hold for a considerable period of time. Yes, I know a better wetsuit would make all the difference in the world...money doesn't grow on trees though.

Ryan

 

[sciencemike]

Interesting story..

Two things. First add some salt to your bags of water. I believe it will inrease the heat capacity of the water as well i know it will make it more dense. Therefore it wont act as a floatation device. Also aluminum foil will do little if nothing underwater. Try thin foam or somthing with air pockets like .... NEOPRENE. You can also try using multiple layers of bags.

* Inner layer - boiling salt water
*Middle layer - 165 F salt water
*Outer layer - 130 F salt water


Secondly i would love to see you with those kids water wings full of hot water. That would make my day.

 

[m2b]

Interesting story..

Two things. First add some salt to your bags of water. I believe it will inrease the heat capacity of the water as well i know it will make it more dense. Therefore it wont act as a floatation device. Also aluminum foil will do little if nothing underwater. Try thin foam or somthing with air pockets like .... NEOPRENE. You can also try using multiple layers of bags.

* Inner layer - boiling salt water
*Middle layer - 165 F salt water
*Outer layer - 130 F salt water


Secondly i would love to see you with those kids water wings full of hot water. That would make my day.

Actually I had thought about the idea of putting hot water in the kiddie floats. If I had some spares on hand I probably would give it a shot and see how well the idea would work. The worst part would be trying to quickly reheat them before a dive session, with ziplock bags its easy to empty/refill.

Does the aluminum foil lose all its standard properties when put underwater??? I know that it is normally used, I thought, for helping to shorten baking time, ie baked potatoes. Also women like to use to reflect the sunlight back onto them when they are out sunbathing. Shouldn't the same reflecting characteristics happen in water as well as out of water? I could almost see the crazed idea of cutting a space blanket in half and using part of it to cover the torso area completely.

Okay, I am sounding silly and stupid ain't I, LMAO!!! That's what happens when it gets late and the full moon is out, people go crazy.

Ryan

 

[sciencemike]

You arent sounding stupid what you are saying makes sense out in the air. What you really need to understand is you need to remove heat transfer through conduction and circulation instead of worrying about reflected heat. Underwater aluminum foil will be worse off than a thin layer of plastic because it will very rapidly conduct heat between compartments. Remember this one rule. In water its CONDUCTION CONDUCTION CONDUCTION. The reason for this is just the difference in densities of the transferring medium.

I still stand by my earlier idea of multiple ziploc bags within each other.

 

[m2b]

Sciencemike,

I'll definitely give the multibag idea a try. I liked it the second I saw it. Here's a question for you based on some kids science fair project I saw on the net, which would keep heat longer salt or glycerin? I saw the results of his experiment, salt not included, and the difference in heat loss between a combo mix of water and glycerin, water and acetone, and milk and acetone all pointed that water and glycerin was the best of the three for keeping heat the longest and reaching the warmest temp. You do seem much smarter than I am on this concept, how does glycerin compare to salt?

Still thinking I might be able to hit November 1st and still be in the water. Two years ago, the only other time I really did any diving, I was out of the water a couple of weeks ago. Granted the water temp than versus now is quite a bit different. This fall has been unseasonably warm compared to any fall that I have lived up here in New England.

Thanks,
Ryan

 

[settingsteel]

this may sound crazy, but would wool longjohns work??? I know wool keeps its heating properties when wet so thought that might be an idea to try, or is this just loco?

 

[sciencemike]

Not so sure about the longjohns. But its worth a try.


As for the glycerine. I would rather teach you how to know whats going on than just tell you the answer. Every chemical/compound has an intrinsic characteristic to it called Specific heat.

Boaring details-----------------------------------------------------
[The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C which is higher than any other common substance. Basically it BOILS (ha ha) down to calorie/gram/C', or in common terms energy/weight for a degree of temp.]
--------------------------------------------------------------------
The more energy/weight C that substance can hold the higher the specific heat of the chemical. What all that means is that a certain volume of water takes a lot of energy to change its temperature one degree.

So for example if Chemical "A" has a specific heat of 2.43 j/g/C and another "B" has 4.186 j/g/C the chemical "B" would warm you almost twice as long.(or in correct terminology it will give you more energy per gram of chemical as it looses its temperature.)

Here is a good table to look up.
http://www.engineeringtoolbox.com/specific-heat-fluids-d_151.html
You now tell me which heats you better, water or glycerine.

 

[shoutatthesky]

Water would release more heat per gram.

This is an interesting measurement but I think we must also consider the other properties of the substance. How would glycerine respond to repeated high temperatures?

 

[m2b]

Okay, you brought up another question then based on an experiment I did a couple of days ago. Before seeing this chart I was thinking of the fluids I knew I had around the house, very few, and decided to try out the one that I knew right where it was at. I grabbed the bottle of used motor oil and put it and water in separate ziplock bags and dropped both of them in a pot of water on the stove. I left them in the pot the same amount of time. When I took them both out I noticed that the oil was at a much cooler temperature than the water. Given what you are saying this shouldn't of been the case, should of it? Also I always thought the longer it took something to heat up the longer it took it to cool off so you would actually want something that took a long time to heat up. Boy is this getting to be quite educational.

This is the webpage that made me bring up the question about glycerine:


It appears that he was mixing the two fluids together and testing them and giving his results. He was doing it for a science fair project.

Does mixing two elements together make them take on the weakest element or a combination of the two?

By the way, water is far better but the real stinker is ammonia, LMAO!

Today is definitely a good day for doing some playing around, it's supposed to rain all day around here.

Thanks for the education,
Ryan

 

[sciencemike]

When I took them both out I noticed that the oil was at a much cooler temperature than the water. Given what you are saying this shouldn't of been the case, should of it? Also I always thought the longer it took something to heat up the longer it took it to cool off so you would actually want something that took a long time to heat up.

I have been thinking about this one for a bit now and i must say i have not come up with a definate answer. But im assuming you made the volumes as close as you could to equal.

Heres the idea that keeps bugging me. We use oil/fat in our bodies to insulate ourselves right... See where im going.. Perhaps oils don't conduct heat well. So a thick (high viscous) oil will get hot on the outside but cold on the inside. Just like our bodies do. Or think about a rod of plastic or a rod of metal. Metal conducts heat very well, so a 100 degree bar of metal seems really hot compared with an 100 degree bar of plastic. The reason for this is that when you touch the metal you are taking the heat from the entire bar of metal because heat transfers very fast throughout the bar. While with plastic you are only getting the heat from a small area around your finger. If you cant imagine this imagine a pizza just out of the oven. You can pick up the crust that is just as hot as the metal, but if you touch the metal you burn yourself. Your experimental observation (very astute i must say) and the fact that all life uses fats as thermal insulation, both agree. So it definately makes sense to me, at least as a possibility.

Does mixing two elements together make them take on the weakest element or a combination of the two?

As you can see from the above experiments that its very complex. Look at the ammonia on the table, it changes its abilities due to temperature. So it obviously involves bonding properties of the chemical, also shown in water when salt is added. I would assume it goes down, for most chemicals when mixed but i definately wouldnt bet my life on it. But i would bet that there will be at least one exception.

By the way, water is far better but the real stinker is ammonia, LMAO!

Yes you and shoutatthesky are correct. Nice job.

Today is definitely a good day for doing some playing around, it's supposed to rain all day around here.

Try this experiment....
Scenario A
Outside bag = oil
Inside bag = Water


And then reverse it
Scenario B
Outside bag = Water
Inside bag = Oil

Wait 10 minutes after heating and see which still is hot.

mike

 

[m2b]

Actually I hadn't tried layering the bags, I had kept them separate. I was just trying, before seeing the chart, to see if oil might keep its heat longer or not. I might have to retry that experiment again the new way. Granted oil is so messy.

Ryan

 

[sciencemike]

The only reason i was thinking about you redoing it was because its probably the answer you really want. You want a long slow heat delivery. Heat the water really hot and the oil warm enough to touch the skin. Then use the oil as a slow release device to slow the water's heat transfer. But that would be a real mess if it popped in your suit. And it will surely mess with your buoyancy.

 

[m2b]

Considering how bad my bouyancy is already, WHO CARES!!! I essentially never wear a weight belt, simple safety since I dive solo(albeit it doesn't matter if you're already dead). I'm still decently positively bouyant at 35 feet. It just would make it harder, more puzzling, to get down in the first place. LOL!!!

Ryan

 

[sanso]

Considering how bad my bouyancy is already, WHO CARES!!! I essentially never wear a weight belt, simple safety since I dive solo(albeit it doesn't matter if you're already dead). I'm still decently positively bouyant at 35 feet. It just would make it harder, more puzzling, to get down in the first place. LOL!!!

Ryan

Please, kids, don't try this at home!
M2b is a trained professional and engages (knowingly, right?) in potentially dangerous diving practises which even he would avoid if he just had a buddy to go diving with.

So, if You're in the area, start freediving and join m2b! It'll be fun!