cozy query

[Chantilly Lace]

I am in need of a new and improved cozy. Mine is homemade from some thin foam I found at the fabric store. It has served me well over the years - lightweight, washable and does what it was made for but just not very well. I need something to hold in the heat longer as I rehydrate my homemade dehydrated meals. The cozy on the antigravitygear site looks to be made of air conditioning insulation. Would anyone venture a guess to what it is made of? What are your cozies made of and how efficient have they been?
Pokemom

[SGT Rock]

It is made from bubble wrap insulation. You can buy it in big sheets at Lowes or Home Depot. If that is too much, a lot of car sunscreens are also made from the stuff. It works, but there is a problem over long term use with the outside mylar de-laminating in high wear spots. I prefer to make my cozies from stuff like old fleece around the house.

[jigsaw]

i made mine out of stuff called refletix they put it under radiant heat then pour concrete over it.its just foil faced bubble wrap i use mine as a bag cozy. i got plenty left over from a job if you want a piece drop me a line. jigsaw [email protected]

[jlb2012]

I made mine from a closed cell sleeping pad from the Army and some duck tape. I have also made them from the blue closed cell pads from WalMart/Target.

[PKH]

I made mine from some light quilting material (my first sewing project). Mine is designed for a Gaterade jar, more or less the same size as the lemonade mugs Sgt Rock uses I think. If its really cold I wrap tinfoil around the jar as well - it still fits nicely in the cozy.

Cheers,

PKH

[steve hiker]

I made a nalgene cozy from heavy duty aluminum foil, a small roll of bubble wrap from WalMart (about $1.50), and duck tape. No need to get fancy or high tech here.

[Chantilly Lace]

My hiking friends have referred to me as the Martha Stewart of backpacking so I must get more fancy and high tech than bubblewrap and duct tape!
Honestly - anything that works is fine!
Thanks for all the input!

Pokemom

[SGT Rock]

HOI's cozy idea is cheap and effective. You could always replace the duct tape with some sort of epoxy and then make it look cool. Maybe even decorate the cozy with some stickers like "Bill Bryson is a candy ass".

[Toolshed]

Reflectix here. My old ones from winter cmaping in the 'dacks are still goung strong after 9 years. I have had no problems with delam or anything of the like. Was a time where you could buy 2'x4' sheets of it for a few bucks. Now it is $17 for a big roll.

[ocourse]

Mine is made from a dollar store windshield reflector.

[bearboy]

mine is also made from a windshield visor. The longest I've used it for is an hour or so. kept it on my porch for over an hour and my food was steaming hot, even in 20ish degree weather.

[smokedog]

I just made one out of a Wal Mart blue pad. Mine fits over a Snow Peak Trec 700, but it seems pretty bulky. Not a lot of room in a Z pack and I'm wondering if it's worth the bulk.

[SGT Rock]

Make one from some sort of insulated cloth like fleece or something. Go to a fabric store and get about a half yard from the clearance bin, it is an easy pattern and you could even hand sew if if neccissary in less than an hour.

[Doctari]

I made mine from a closed cell sleeping pad from the Army and some duck tape. I have also made them from the blue closed cell pads from WalMart/Target.

Me 2, & I used CAMO duct tape :-)

I am constantly loosing the darn thing, can't see it.



(I lie: never loose it, but thought it funny)

Doctari.

[PKH]

Oven mitt material will make a fine cozy if you have any sewing skills.

Cheers,

PKH

[smokedog]

Great idea about the oven mitt. Think I'll get out the ol' needle and thread and go to work.

[SGT Rock]

Look for some light nylon for the outside (mine is 0.8oz ripstop) and some lame with the insulation already sewn to the inside. My latest one is about 25 grams:

http://hikinghq.net/ionstove/images/100_0321.JPG

http://hikinghq.net/ionstove/images/100_0322.JPG

I use it as the sack to keep my pot/stove/windscreen/fuel bottle/stand/lighter system inside it.

[smokedog]

Look for some light nylon for the outside (mine is 0.8oz ripstop) and some lame with the insulation already sewn to the inside. My latest one is about 25 grams:

http://hikinghq.net/ionstove/images/100_0321.JPG

http://hikinghq.net/ionstove/images/100_0322.JPG

I use it as the sack to keep my pot/stove/windscreen/fuel bottle/stand/lighter system inside it.

This one looks interesting. Couple of questions: What is "lame"? Is that a typo? Is is difficult to slide the boiling pot down inside the cozy? I thought a better plan was to slide the cozy down over the pot.

[hiker5]

I'm thinking I'll pick up some Reflectix in the not too distant future to make a cozy for my grease pot. Any suggestions on the best method of attaching pieces of Reflectix together? It looks like if you buy it on a roll, it has a staple tab on one side that could aid it joining a cylindrical piece (circumference of the pot) to a flat piece (circle for the bottom). So far I've considered duct tape, sewing, adhesive, or some sort of Velcro closure. Thoughts?

[Chantilly Lace]

Thank you all for your input on cozy materials. Jigsaw sent me a piece of refletix but I haven't had time to sew up a cozy yet. I may try using the windshield reflector, too, when I find one at the dollar store.

The practicality of using oven mitt material isn't a good idea, IMO. Way too heavy.

Sarge, the pictures of yours are great!! Did the army teach you to sew? What army was that? - my husband is in the army and he doesn't know one end of a needle from the other.

Smokedog, the pot or bowl is best set inside the cozy and use a drawstring to close it up around the top. Don't slide the cozy down over the pot for the food may need to be checked for doneness.

Pokemom

[SGT Rock]

This one looks interesting. Couple of questions: What is "lame"? Is that a typo? Is is difficult to slide the boiling pot down inside the cozy? I thought a better plan was to slide the cozy down over the pot.

Lame is not a typo. Lame is a fabric that combines metal and some sort of fabric, in my case it is aluminum and nylon, very light and reflective. You can find it in a fabric store.I had some old insulation laying around that was quilted in between the rip-stop and lame to provide the heat retention. As an experiment we also bought a half yard of lame with polyester batting already quilted to it so all you had to do is add the shell, it came out the same weight and about the same thickness.

BTW, I didn't sew it, my wife did, but it isn't a hard project.

Mine has a slit on one side that Velcros closed (see the black tab of Velcro?) that you can open up to slide the pot in with the handles out, then Velcro it closed and cinch the top up while it simmers. When your ready to eat, just open it up and fold over once then you can eat unobstructed. I prefer fabric over the reflectix because it can be machine washed anytime you do laundry, it weighs less, and it packs easier. My cozy is also my pot storage bag.

[The Weasel]

This is actually one of the few things I've really spent some time on...

Heat-loss prevention is a combination of two things: Reflective ability, and insulative ability. Of the two, insulative ability has the most 'punch' in a small item like a cozy. I've tried some of the reflective fabrics (space blankets, including the 'better' ones that are ripstop fabric with reflective aluminum sewn on), and by themselves, while they are better than nothing, they don't do a lot, as anyone who has tried sleeping inside one without a bag in cold weather can tell you. Much like that situation (sleeping bag alone better than space blanket alone), I've found that insulation works best.

Of all the choices, closed cell foam is the best I've found. But there are different densities of that too. So far, the densest I have found has been the Coleman brand ground pad, which is also a little thicker than other ground pads (including those given to Rock as part of government issue).

Assembly matters, too, both for insulation as well as for weight/packing. I cut an oblong that is 1" longer than the circumference of my pot, and then bevel the two ends so that they overlap. I then get 2" radiator hose tape (holds up to heat VERY well) and overlap that around the joint. I cut two circles for the bottom and the top, each about 1/2" diameter larger than the pot, and insert the bottom snugly just before I put the pot in, and then cover with the other snugly. There is virtually no heat loss.

As a result, I'm able to cook pasta/rice/grits by bringing my water to a boil, putting in the ingredients, and put the pot inside the cozy, where the cooking finishes over the next 20 minutes. I've got it down to where my "fuel use" is about 2 minutes per pot.

The key is to get the densest foam possible, but I don't think over 3/4 inch makes any difference, and then to seal the joint with overlap. Early cozies I made without the bevel had heat loss through the joint (I could feel it).

Despite Rock's delight in stickers, I think those are a bad idea, since even a little seepage of unnecessary adhesive can reduce the insulative effect. Use the minimum of tape, as well; for my next cozy, I'm going to experiment with joining the ends of the oblong with high-temp epoxy, although I'm uncertain of whether that will result in a hardened (and hence heat-sink capable) joint.

I know this is pretty anal, but a well made cozy is a bit of art, and, unlike most other equipment, something even a doofus like me can have fun making without going totally bonkers. (Rock, I could NEVER test/create stoves liike you!)

Hope this is of use to someone.

The Weasel

[Footslogger]

You have to be pretty serious about the whole cozy thing to make it work ...and I guess I wasn't. I followed the available "cozy wisdom" at the time prior to my thru-hike in 2003. I built one out of the closed cell foam, similar to the one outlined by Weasel in the previous thread. I used it from Springer to Neels Gap and by then I lost interest in dealing with the whole process. I found that I could pretty much duplicate the success with meals without the cozy. I would fill my Ti pot with the requisite amount of water and soak my noodles, rice, whatever prior to cooking. Then I'd fire up my stove and bring the contents to a rolling boil. I'd take it off the stove, extinguish the flame and then let it sit on the pot stand for several minutes. At that point I would remove the lid and dig in.

May just be me ...but I'm so damn hungry on the trail that the food doesn't have a chance to cool off much before it's in my belly.

'Slogger
AT 2003

[SGT Rock]

First off, It is GREAT to see you posting more here friend!

This is actually one of the few things I've really spent some time on...

Heat-loss prevention is a combination of two things: Reflective ability, and insulative ability. Of the two, insulative ability has the most 'punch' in a small item like a cozy. I've tried some of the reflective fabrics (space blankets, including the 'better' ones that are ripstop fabric with reflective aluminum sewn on), and by themselves, while they are better than nothing, they don't do a lot, as anyone who has tried sleeping inside one without a bag in cold weather can tell you. Much like that situation (sleeping bag alone better than space blanket alone), I've found that insulation works best.

I totally agree with this. I like the Anti-Gravity gear cozy for a few reasons, but Reflectix is not a great insulator. I did some reading a few years back on this particular material and the aplications it was designed for and what the R value really is when used in contact with the body you are trying to insulate. To make it short, you are only getting an R value of something like 1.5 when used as a cozy



Of all the choices, closed cell foam is the best I've found. But there are different densities of that too. So far, the densest I have found has been the Coleman brand ground pad, which is also a little thicker than other ground pads (including those given to Rock as part of government issue).

Assembly matters, too, both for insulation as well as for weight/packing. I cut an oblong that is 1" longer than the circumference of my pot, and then bevel the two ends so that they overlap. I then get 2" radiator hose tape (holds up to heat VERY well) and overlap that around the joint. I cut two circles for the bottom and the top, each about 1/2" diameter larger than the pot, and insert the bottom snugly just before I put the pot in, and then cover with the other snugly. There is virtually no heat loss.

That does make a good cozy. My first was a similar design, my main issue was my pot was curved to the bottom and the cozy didn't fit it well, that is why I changed material for my personal cozy.

[/quote]
As a result, I'm able to cook pasta/rice/grits by bringing my water to a boil, putting in the ingredients, and put the pot inside the cozy, where the cooking finishes over the next 20 minutes. I've got it down to where my "fuel use" is about 2 minutes per pot.


Not bad.

[quote]
The key is to get the densest foam possible, but I don't think over 3/4 inch makes any difference, and then to seal the joint with overlap. Early cozies I made without the bevel had heat loss through the joint (I could feel it).

Despite Rock's delight in stickers, I think those are a bad idea, since even a little seepage of unnecessary adhesive can reduce the insulative effect. Use the minimum of tape, as well; for my next cozy, I'm going to experiment with joining the ends of the oblong with high-temp epoxy, although I'm uncertain of whether that will result in a hardened (and hence heat-sink capable) joint.


I think this is where I diverge on stratagy. While I won't deny you are right on, my strategy has been simply to maintain a temperature above 200F for at least 15 minutes. Since the pot with food and water acts like a heat sink, I am not trying to do a whole lot of extra insulating. What I prefer is keeping the cozy as light and as compact as possible in my pack while still meeting my goal. Now my last cozy was very impressive, but it was made of this space age aramid cloth that someone sent me some scraps of to play with. It was tested to maintain heat above 200 for about 30-35 minutes and only weigh 0.8 ounces while being as thin as felt. I tried finding some to make a new cozy from, but the stuff I found would be more expensive than my Ti pot. I haven't tested the insulation of this new cozy yet, but I will. If it needs more insulation it will get some.



I know this is pretty anal, but a well made cozy is a bit of art, and, unlike most other equipment, something even a doofus like me can have fun making without going totally bonkers. (Rock, I could NEVER test/create stoves liike you!)

Hope this is of use to someone.

The Weasel

I think it is usefull. A good cozy is a thing to enjoy:D

[hiker5]

It sounds like the discussion of how good an insulator reflectix is comes down to which method of heat transfer you are considering. My understanding is that it is very effective at preventing radiative heat transfer, but from what Sgt. Rock is saying (1.5 R value) it may be a rather poor insulator when it comes to contuctive heat transfer. Perhaps I'll have to crack out my heat transfer text book see just how much is contributed by radiative transfer compared to the conductive (combined with convective from the outside of the cozy to the air).

Has anyone seen a data sheet on the thermal properties of reflectix?

Edit: I meant to add that I suspect that conduction will dominate the process unless you leave a small air gap all around the pot so the cozy isn't such a snug fit. Air is an awfully good insulator.

[snarbles]

Isn't Neoprene an insulator as well? I think these Neoprene "Cozy Covers" would make a fine Cozy themselves:

http://www.antigravitygear.com/store/product_info.php?cPath=3_13&products_id=142

Any reason why using these w/o the bubble foil wouldn't work?

[Auntie Mame]

I wonder about omitting the cozy altogether, and just dumping the boiling water into the ziplock full of dry food. Bill McCartney talks about this in his little cookbook on trail food, and it sounds good. He tucks the bag into a fleece hat for a few minutes, eats out of the bag and tosses it in his trash bag. No washing the pot, and just a fabric cozy to tote. Takes a little prep at home to get the ingredients bagged up, but could also be done after a food run.

[SGT Rock]

It sounds like the discussion of how good an insulator reflectix is comes down to which method of heat transfer you are considering. My understanding is that it is very effective at preventing radiative heat transfer, but from what Sgt. Rock is saying (1.5 R value) it may be a rather poor insulator when it comes to contuctive heat transfer. Perhaps I'll have to crack out my heat transfer text book see just how much is contributed by radiative transfer compared to the conductive (combined with convective from the outside of the cozy to the air).

Has anyone seen a data sheet on the thermal properties of reflectix?

Edit: I meant to add that I suspect that conduction will dominate the process unless you leave a small air gap all around the pot so the cozy isn't such a snug fit. Air is an awfully good insulator.
No scientific ones that I know of that do comparative testing of pot cozies. BPL did test the A cozie by doing diffferent tests including making two pots of hot water, putting one in an AG cozy, and then putting both in a freezer. During the cooling test they compare the two and found there was some value added in using a cozy - but I forget the exact conclusions at this point.

[Dances with Mice]

I wonder about omitting the cozy altogether, and just dumping the boiling water into the ziplock full of dry food. Bill McCartney talks about this in his little cookbook on trail food, and it sounds good. He tucks the bag into a fleece hat for a few minutes, eats out of the bag and tosses it in his trash bag. No washing the pot, and just a fabric cozy to tote. Takes a little prep at home to get the ingredients bagged up, but could also be done after a food run.That's about what I do, but I made a little envelope out of a reflective car window shade, Reflectix-like material if not the same. Slip the bag into that. Takes no prep at home except buying the 'freezer'-rated ziplocks.

Because sometime, somewhere, and when you least expect it - the seal on the bag is going to come undone. Bet the farm on it. And that could make your hat fit funny.

[Auntie Mame]

I like that! A flat little sleeve, kind of?

[Dances with Mice]

I like that! A flat little sleeve, kind of?Exactly. I just used a fold on the window shade as the end crease of the cozy. Laid a ziplock bag over the doubled windscreen and cut to size. Taped the cut sides together with flue tape, but duct tape should work. I left a little flap to fold into the envelope to seal the top, seemed like a good idea at the time but now I don't think it's necessary. I also made mine the same size as a quart freezer ziplock but that's about twice too big, a Liptons and a meat foil pack together only fill about half the ziplock, so the cozy could be smaller. Still weighs next to nothing. And it's easy to rinse out when necessary.

[Frolicking Dinosaurs]

Great ideas - I'd never considered using lamé in a cozy. Wonder if lamé could be used in a homemade quilt or sleeping bag with similar toasty results?

For those still puzzled about what lam&#233; is - see this web site for photos and descriptions www.distinctivefabric.com/<wbr>category.php?cat=SHINY (http://www.distinctivefabric.com/category.php?cat=SHINY)

[Marta]

That's about what I do, but I made a little envelope out of a reflective car window shade, Reflectix-like material if not the same. Slip the bag into that. Takes no prep at home except buying the 'freezer'-rated ziplocks.


I've made a pouch using the bags sold in the grocery store to carry icecream and frozen food in the summer. Silver on both sides with some insulation in the middle. I used duct tape as the fastener. Not elegant but cheap and easily replaceable if your meal springs a leak and ruins the insulated pouch.

Ditto to the notion that the freezer bags are worth the money. I haven't had any leaks since I switched to them.

[SGT Rock]

Great ideas - I'd never considered using lamé in a cozy. Wonder if lamé could be used in a homemade quilt or sleeping bag with similar toasty results?

For those still puzzled about what lamé is - see this web site for photos and descriptions www.distinctivefabric.com/<wbr>category.php?cat=SHINY (http://www.distinctivefabric.com/category.php?cat=SHINY)
Actually yes thy have :D

I have a cozy that was made with some leftovers of another project. So it has a DWR 0.8 nylon shell, polarguard 3D batting, and a lame liner. My wife then whipped out some that we thought about offering at www.ionstove.com that are made with a nylon shell and have a lame liner with a simple nylon batting insulation layer quilted in-between. My sons and I all carry these sorts of cozies.

[snarbles]

Actually yes thy have :D

I have a cozy that was made with some leftovers of another project. So it has a DWR 0.8 nylon shell, polarguard 3D batting, and a lame liner. My wife then whipped out some that we thought about offering at www.ionstove.com (http://www.ionstove.com) that are made with a nylon shell and have a lame liner with a simple nylon batting insulation layer quilted in-between. My sons and I all carry these sorts of cozies.

That would certainly be cool, I do really like the idea of the sack/cozy combo idea based on the insulation principal. I'll keep an eye out in case you do offer this design on your site one day.