How do I keep a cool box cool for 4 days?

[Thurston Garden]

Not especially ISH, but you helpful bods may well have some ideas!

I am going to Cropredy next week and will be camping for 4 days. I have a 12v cool box which will be plugged into the car for the journey south. My issue is how to keep the box cool for the duration of the festival.

I did a wee trial recently at a two day festival, again running the cool box off the ciggy lighter in the car, but then off a car battery when camping. The car battery (40Ah), despite being fully charged only lasted a few hours. I do have a liesure battery (120Ah) but it's on it's way out and wont hold a charge properly.

So my question is: how can I keep my cool box cool without a. the expense of a solar kit to keep the car battery topped up (even if shuch a thing exists) or b. having to run the car periodically to power the cool box - neither of which I am even thinking of doing!.

I know of the wet towel placed over beer cans as a kind of mini-solar-fridge, but cant see this as a practical 4 day solution.

Any suggestions on how I can keep my Pimms cool for 4 days?

[Milims]

Freeze as much stuff as you can before you go and put it into the box frozen. It will gradually defrost but help to keep stuff cool in the meantime. The colder it is when you start off the longer it will stay cold. Don't forget to insulate it well too. Have fun!

[Thurston Garden]

Doh! How thick am I? Top tip from Milims!

[Annpan]

I was going to suggest the same but with ice packs. Keeping the whole thing in a white pillow case might help to keep it cooler too? just to reflect the suns rays.

I plan on making ourselves a camping pot in pot cooler... made from stiff fabric that can be filled with sand, or maybe just toweling... still thinking it through.

[paul123456]

A mixture of water and salt ?

I went to school somewhere in the last century , I can remember something of a combination of salt and water freezing down to -
21 degrees ?

Starting to doubt now ...
better finish my beer ,

regards ,

Paul

[frozenthunderbolt]

Dry ice? liquid nitrogen? know anyone in lab . . .

[the.fee.fairy]

Tin foil? Won't it reflect the rays on the outside, and reflect the cold on the inside or something?

I'm sure there was something about it in science...

[EmpressG]

Colman here in the US makes a "five day cooler". The "trick" is extra insulation.

So you could add more insulation to the one you have. I suggest adding mylar bubble wraphttp://www.amazon.com/Reflectix-BP24050 ... B0009XCJA2, like is used for transporting fish to pet shops or for car window shades when the car is parked, to the inside and outside. It is available at hardware stores and called Reflectix here. I use that stuff to make all kinds of stuff including a solar cooker. My sister works in a Pet shop and collects the fishbags for free. We have used them to insulate rooms, animal pens, and she is saving it to insulate a house she may build one day. Neat stuff!

In fact you can make a very nice solar cooker from a cooler using foil, mylar bubble wrap and a glass or plexiglass lid cut to fit.

[Mainer in Exile]

I usually use old newspaper as insulation. So far it's worked pretty good, 4 or 5 days on fishing trips, with enough ice left to keep the fish cool on the way home.

[Thurston Garden]

Top tips! I think I am going to freeze a few small milk cartons (but leave one defrosted for ready use). I will freeze any other items that I can. I don't have any of them blue ice blocks, but wondered about filling any voids in the packed cool box with bags of ice?

I will also look at additional insulation - it's this box although it's twice as expensive as it was a few weeks back! There's surely scope for some newspaper/bubble wrap between the plastic box and the fabric outer

Thursday is D-Day for the 4 day trip. I shall report on progress!

[healer]

Hi I know this is an old question but lots of people are still looking at it so I'll add my bit. Powermonkey - portable solar power and recharger have been used in Africa to keep vacinations cool boxes cold (so vacine doesn't go off!) I'm not promoting the product but if you health or or others is at risk if the cool box is not kept cold it would be worth the step into techno fix culture - you can also charge you mobile and laptop (both seem to be now very important part of self sufficiency!! )

[wulf]

Water. Heat is lost through evaporation so keeping the outside of the box wet (perhaps sitting it in a bowl and splashing some on top from time to time) would help.

Wulf