Dry ice versus reguler water ice

[Team Piggy]

I an planning a trip away over easter, and intend to be camping for up to 10 days , without little girl Paige.That's why its 10 days planned,we may end up aborting the trip early if Paige doesn'st settle in to the camping life.

??? That made sense ???

The accumulation of dry ice in a concealed cabin area can be deadly ! .
Here s some technical jargon from Doctor bob..Some vetenary website that uses Dry ice for ?something? Freezing monkey sperm perhaps (want a second job pesky ?)...

Precautions
1. Use as little CO2 as possible.
2. Know the danger that this imposes in the given environment.
3. Do not store dry ice in an unventilated room or in a room with animals.
4. Place warning signs on all entrances to rooms containing dry ice and keep doors locked.
5. Ventilate rooms by leaving doors open for several minutes before entering rooms that contained dry ice in the past 12 hours.
6. If the calculated maximum potential concentration of CO2 in a room exceeds 3 % or 30,000 ppm then two people must be present upon opening the room if the door has been closed for more than 5 hours.
7. Never carry dry ice in a car. Doing so is not only extremely dangerous but it is also illegal in many institutions, like ANU. The exception is a vehicle, like a utility, where the dry ice can be separated from the passenger compartment. Note that the boots of many cars are not separate compartments.
8. Always wear your underwear on the inside. (Piggy might have made this bit up)..

pesky, I would stick it up on the roof, next to the diesel & phosphate bomb , Dont have it in the car or in a tent at any time.. Should be Ok, from there.

Have a great trip..

[SNIFTER]

I wouldn't even consider dry ice for refrigeration on a camping trip.
We used dry ice for fog machines and ICI made sure we drove out of the yard with dry ice in an open vehicle.
If you are going to be away from humanity for so long think of other ways to keep food.eg powdered milk to add to your bottled water. Freeze your meat before you go and then wrap the meat which is in plastic first with newspaper. The frozen meat will keep your cheese, butter, eggs etc fresh as well.Lasts up to 5 days if out of the sunlight.
Have you considered a portable fridge like a waeco. They plug into your battery or you can get gas ones.
The only other way is to go to the nearest garage and buy regular ice and start by making your own in 2lt bottles. That way you keep everything cold and as it melts you have fresh water.
I have never thrown anything out during a camping trip. You need to plan in advance just what you plan to eat and stick to the plan.

[Richary]

The other option for keeping food fresh is vacseal meat. Check with your local butcher, there is probably someone who does it in your area. Here I can get it done at an extra $1 a bag.

Basically they suck all the air out and red meat should keep for about 2 weeks and chicken etc for about 1 week. As long as they are in the fridge anyway. Had this done when I went to the Flinders for 10 days last year and it worked really well. Doesn't solve the fresh meat problem and you do need to be running a car fridge but it's one answer.

As someone else mentioned, fill a plastic coke bottle almost full of water and freeze it. They will stay frozen for about 3 days in an esky, depending on how many warm beers you are adding anyway!

[The Spindoctors]

Dry ice for this prupose is bad news. As mentioned, the dry ice needs to be kept in a seperate cell from these travelling. I used to use liquid nitrogen for science shows and we were told by Orica (ICI) of an incident where a person pulled onto the side of the road during a long trip, for a nap, and never woke up. Cost and transportation isn't worth it.

Vacuum sealed meat is the way to go. Freeze dried is another option (my fav). A bit hit and miss with various meals, but it's fun. Otherwise, venture back to a store every few days.

One idea off the top of my head. Try 2lt bottles with frozen salt water. It stays colder (-18 degrees C) for longer.

[Mind Socket]

I'm not so sure about the salt water idea. Salt water does have a lower freezing temperature, so I reckon saltwater ice at -18C will melt by the time it hits, say, -16C. On the other hand, if you freeze unsalted water to -18C, it will stay solid until it warms to 0C.

My physics/chem is a little rusty, but with a lower freezing point and assuming the same rate of heat transfer, salt water would probably be worse.

Isn't this why they put salt on alpine roads in winter? It's effectively anti-freeze.

- Rog

[the odlids]

When you say camping for 10 days, I take you mean in one spot, in the middle of nowhere? 10 days is an awful long time.

My suggestion would be to buy a decent icebox, not one of those Kmart plastic specials but a real icebox. Something from the EVAKOOL or Engel range. There are quite a few on the market now, they arent exactly cheap but they do a great job.

These things consist of a resin outer and inner shell with really good insulation. We put about 5 or 6 deep frozen water filled 2 or 3 litre milk containers into them and then add your precooled food from the fridge. At the last available ice supply we top up the fridge with some party ice. It is not uncommon to still have ice 5 or 6 days into the trip and that is in summer! The added bonus is that you have cool drinking water in the milk cartons as they melt.

We are presently setting up our new 4WD for extended touring/camping and our intention is to run a small engel refrigerator(in freezer mode) to make ice in milk containers and then transfer them to a larger EVAKOOL icebox for our general fridge use. We do of course have an auxikiary battery setup in the Cruiser to ensure our main battery integrity.

Anyway hope the info helps.

Cheers
Odlid Dave

[Team Red Roo]

I don't know where you intend to go, but in my previous camping history, we always planned our food without 'cold'. Simply - no fridge and no esky. Bottles of wine were put in a stream or the ocean to cool and meat was cooked the day we bought it. Other than that we used UHT milk and tinned foods.
Now we use a camper with a fridge, so the wine comes out colder.

[EcoTeam]

I'm not so sure about the salt water idea. Salt water does have a lower freezing temperature, so I reckon saltwater ice at -18C will melt by the time it hits, say, -16C. On the other hand, if you freeze unsalted water to -18C, it will stay solid until it warms to 0C.

My physics/chem is a little rusty, but with a lower freezing point and assuming the same rate of heat transfer, salt water would probably be worse.

Isn't this why they put salt on alpine roads in winter? It's effectively anti-freeze.

- Rog

Yep, salt water will melt at a lower temp, and water will most likely conduct heat away (and hence warm faster) than pure ice will. But obviously, a -5degC block of pure ice is the same temp as a -5degC block of melted salt water
Actually, it's not just salt, but any substance dissolved in water will lower the freezing point. Salt is used to melt roads etc because it's cheap.

EcoDave

[bmac]

Adding salt will keep it colder, so you could say take ice-cream, but will last a shorter time, since there will be a greater difference in temperature between your esky and the air temperature.

<p>Depending on what temperature you want, you can try the following mixtures (taken from the Merck Tables for the chemical laboratory):

<table>
<tr>
<td>Mixture (parts by weight)</td><td> Temperature (deg C)</td></tr><tr>
<td>4 water + potassium chloride</td><td> -12</td></tr><tr>
<td>1 water + ammonium nitrate</td><td> -15</td></tr><tr>
<td>1 water + sodium nitrate + 1 ammonium chloride</td><td> -24</td></tr><tr>
<td>3 crushed ice + 1 sodium chloride</td><td> -21</td></tr><tr>
<td>1.2 crushed ice + 2 calcium chloride </td><td> -39</td></tr><tr>
<td>1.4 crushed ice + 2 calcium chloride </td><td> -55</td></tr><tr>
<td>methanol or acetone + solid carbon dioxide (dry ice) </td><td> -77</td></tr>
</table>

<p>I wouldn't recommend the last one. Neither methanol nor acetone go very well with food.

<p>bmac

[SNIFTER]

Forget about the scientific formula just go buy some 2 minute noodles of different flavours and then all you need to do is boil some water. Bingo....problem solved.

[Team Piggy]

Pesky.

Check out your local 4wd hire shops too.

Occasionaly We have hired Engels / Waeco fridges for our workers when they go bush for a few days.

Not too bad on price, maybe thats an option?

I think the battery in your car would suffer if you werent moving daily though. Just a thought.

[ToolkiT]

And remember the toilet paper trick for cold beers!!

[mtbikeroz]

one final comment - for amusement..........Agree with all the safety issues described above etc etc etc...........

I was on a camp once 22 yrs ago (shops were shut fri night back then) and for some reason the organiser arranged some steaks to be brought in from 50+km away for a "special" event on the Sat. night - well he used dry ice to keep the meat "fresh" & chilled - he was good in that he had a window open all the way, BUT when he arrived and we tried to cook the steaks - they were so so hard & frozen to minus 180 degrees C or whatever, it took AGES and AGES to thaw the really thick things out on a scorching bush BBQ - needless to say we had a late BBQ tea that night.