EDC, actual use or just in case?

[dks]

The wool should be inside trapping air (air is an insulator) and stopping loss heat due to convention, (movement of hot air) with the other blanket outside, stopping the outside, cold, air from reaching the wool and the hot insulating air from escaping, again limiting heat loss by convention, movement of hot air from the inside to the outside. If you put the thinner blanket inside touching you then heat will go through it by conduction, rather than radiation, so it is of very little use, as I assume is designed to stop radiated heat, not conducted.

Basically fur coats will be warmer if they were worn inside out..   

This is done in years 7,8,9 and O-level Physics, by the way, so it is nothing too clever.

However, sometimes reality defies the theory...

[Taxi Dad]

i have an O-level in physics 
but it was a long time ago   
i have trouble remembering last week let alone that far back 
but thanks for the answer, i would have put my money on that way round, so perhaps i'm not an idiot despite general opinion 

[Steinar]

you're not boring anyone ! knowledge is always good to have 
I wonder could you answer a question for me , you sound like you know your 'stuff' , i've not been able to find a definitve answere to this one
" if you had a space blanket and wool blanket , which would be the best (warmest) way to wrap yourself in them ?" (foil under wool or over the top trapping heat in the wool)
if you were out of the rain and wind obviously, in a shelter perhaps .

Foil would stop radiated heat (loss), wool will stop convective heat loss. Under normal circumstances, I'm pretty sure convective heat loss dwarfs radiated heat, since we are pretty close to our surroundings in temperature, but that's mostly a gut feeling. Also, and this is just as important, a foil will catch condensation and you may get damp. Wool breathes.

I strongly doubt there's much of a dependency between wave length in the IR spectrum and how much is reflected by a foil, pretty sure most of it is reflected anyway.

Disclaimer: Neither thermal physics nor cold weather rescues are my profession. I do have some formal education in physics a long time ago, though.

Oops, dks has already answered, ah, well. Here goes anyway, everything to reach the next 666 666 666 articles.

[dks]

it is funny, however, how many times what you expect from science to happen does not actually happen in real life.  So if an expert tells you how to use these blankets/tools, after using them fro several years his opinion may be more valid than the theory.

[Steinar]

it is funny, however, how many times what you expect from science to happen does not actually happen in real life.  So if an expert tells you how to use these blankets/tools, after using them fro several years his opinion may be more valid than the theory.

That just shows you have been using the wrong model. You have the old urban myth about science claiming bumblebees shouldn't be able to fly, for instance. That's because some time in the forties or fifties a guy modelled a bumblebee as a stiff structure and basically concluded that if bumblebees were fixed-wing aircraft, they wouldn't fly. Which isn't very surprising... If you model correctly, as an elastic, dynamic structure, the map and the terrain are beautifully similar.

Experiment always trumphs theory, but you're never quite sure what you're really observing...

[Lynn LeFey]

" if you had a space blanket and wool blanket , which would be the best (warmest) way to wrap yourself in them ?" (foil under wool or over the top trapping heat in the wool)
if you were out of the rain and wind obviously, in a shelter perhaps .

I think it's always going to be emergency blanket over wool. The emergency blanket doesn't breath, meaning you're likely to get moisture buildup under it. The wool should help wick that away, and wool stays as a good insulator even when wet. My opinion, not true tested fact.

dks, this is the kind of emergency blanket I'm talking about. Aluminized polyester. they have been described by other folks as a 'poptart wrapper', and i think that's fairly accurate.
http://www.coghlans.com/products/emergency-blanket-8235

EDIT: wow... missed a whole page there. Sorry. Also, Steinar, my little kit has that blanket, a heavy duty ziplock bag and water purification packets, lighter, light cordage, duct tape. I live in a river valley. Water is always accessible.

[dks]

Thanks.  I have seen these in marathon races (from TV) when they cover the runners to keep them warm, or cold... 

[Steinar]

EDIT: wow... missed a whole page there. Sorry. Also, Steinar, my little kit has that blanket, a heavy duty ziplock bag and water purification packets, lighter, light cordage, duct tape. I live in a river valley. Water is always accessible.

Sounds like a very reasonable setup,    What do you use as tinder?

[Lynn LeFey]

What do you use as tinder?

Cottonballs or dryer lint coated in parafin. I prefer parafin to petrolium jelly as it's less messy.

[16VGTIDave]

I also use dryer lint with paraffin, but have found that lint and petroleum jelly is easier to light with a fire steel and/or in adverse conditions. That said, it doesn't burn as hot or as long as paraffin.

To transport this gooey mess without the mess, I use large diameter drinking straws (the kind used for Slushies). I use needle nose pliers and a lighter to melt one end closed and then fill the straw with the lint and pj, packing it in as tightly as possible. Then I squeeze the end closed with the pliers and melt it closed. Once it has cooled, I squeeze the tubes to ensure they are sealed, then into the kit they go!

Dave


Sent from my iPad2

[Lynn LeFey]

I've been practicing my drinking-straw sealing technique, but for chlorine bleach (for water purification). in theory, 2 drops should be enough for a quart or liter, but I put in 3, assuming some will be wasted. I usually store my tinder in a film canister, in the event of high heat to make sure parafin doesn't get all over everything.

[AimlessWanderer]

If you split your tinder into smaller quantities before storing in your film canister, and wrap them in tin foil, they could be more useful. Foil wrapped cottonwool/vaseline (only a small portion exposed) will burn far longer and can actually be used as a candle. Useful if your kindling is not as dry as you'd like

[nuphoria]

Ah, a candle too.... that's a useful idea