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General => General Discussion => Topic started by: Jeepers Creepers on September 02, 2012, 04:07:23 AM

Title: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 02, 2012, 04:07:23 AM
We'll have the milk etc, in the gas fridge, but to keep our sports drinks (BEER) cold, i was going to take our rather old esky.
It still works OK and all that crap, but to keep the beer extra nice and cold, i was going to "salt the ice"

Now, I've never done the salt on ice before, but have been told, it will last longer and be colder.... is that correct?

The reason i ask, oh great camping guru's of the cosmos, is that I'm of the belief, that they salt roads to melt the ice in cold climates.

So, will salting the ice, make it colder and last longer (sounds like an ad for Mr. Wobbly nasal spray erection stuff) or will it melt the ice quicker?

I guess I'd really like to hear from someone that's done it before or has a science degree.

Oh alright, anyone can answer......  :D
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: fuji on September 02, 2012, 05:58:50 AM
When I was a youngun and lived overseas in Sth Korea, the US Military used to throw salt on the icy and snowed in roads. It worked so I think that salt does melt the ice. I suppose you could buy some cheap pool salt and give it a try. Probably cost $15 total IMO. Cheers
Wayne
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: HEM19X on September 02, 2012, 06:40:10 AM
In the good old days, the local fish co-op used to freeze salt water for the trawlers to keeps prawns cool as salt water freezes at a lower temp than fresh.

We have a 2nd fridge in which we turn the freezer section down as cold as it goes, leaving the ice in that makes it last longer - However never tried salting ice as it makes the bundy & coke taste funny!
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 02, 2012, 06:44:33 AM
This is interesting, been googling the question.

Most seem to say, it wont make the ice last longer, but would make it colder.

You would think, if it has lowered the freezing temp of the water, it would have to last longer.  ???

I'm going to mix some salty water up later and freeze it and see how it goes.
The only real test i guess, would be to do two matching eskies in every aspect and do a mythbusters thing on it.

Still keen to hear from someone that has tried it.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: speewa158 on September 02, 2012, 07:10:25 AM
Buy a bigger Engel & dont do drugs  :cheers:
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: swoffer on September 02, 2012, 08:02:38 AM
Yep , definately works . I'm a comm fisherman of about 30 years and in our pre refig on the boat days thats exactly what we used to do to get more life out of our block ice . Fish will actually freeze in a extra salty slurry .
As already mentioned tho the main drawback is it makes ya Scotch taste like pee  ;D ;D
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: rodw on September 02, 2012, 08:05:20 AM
It will certainly get your beer colder but expect to end up with frozen beer.  I remember doing this years ago using garbage bins as the ice chests, salt and ice to keep the beer cold on the beach near Tin Can Bay. The salt makes you thirsty, the beer freezes, you drink as much beer as you can defrost to quench the thirst and you wake up with the biggest hangover you can imagine!

In the old temperature scale, water froze at 32 degrees F and salty water froze at 0 degrees (-17.8 Degrees C). The temperature in a home freezer is -15 degrees C so you can see that you will have no trouble freezing your beer with salted ice.

Good luck!
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 02, 2012, 11:48:31 AM
OK,  i've mixed up the salty stuff in 3 separate 2 litre containers to place in the esky.

I'll turf a bag or two of party ice around as well and see how it works.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: UR-50-LO on September 02, 2012, 01:40:18 PM
When I had my boat I'd make a slurry to keep any fish in good condition.
Started off with frozen salt water and would pour a bit of ocen water over the 2 litre ice blocks when we got to the boat ramp. Temp would get low enough to make your hands ache when you put them in the cooler and would semi freeze anything inside....
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: SteveandViv on September 02, 2012, 03:13:42 PM
The salt changes the chemical composition of the water which allows the water tb colder with out freezing. The bets test is to put two different ice cream container in the freezer and then check out how the standard water one freezes at 0 and the salt water one freezes at -4.

If you make the ice with salt before you go away then it will last longer in the Esky because it melting point is lower so the slurry is colder, make for a great beer in a -4 slurry than a 0 slurry.. Just adding salt to the ice will allow the water/ salt mixture to be liquid at a lower temp and it should  last longer, at the start in any case

this same principle was used on roads. By adding the salt the ice would melt to a slurry quicker and then run off the road. Wasn't so good for the rust factor though
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Tassie devils on September 02, 2012, 04:48:19 PM
Triple j 11am Thursdays phone in doctor Carl he will know the answer :cheers:
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: JU5T1N on September 02, 2012, 06:05:57 PM
I'm going to mix some salty water up later and freeze it and see how it goes.
The only real test i guess, would be to do two matching eskies in every aspect and do a mythbusters thing on it.
forget doing a Mythbusters, do the Brainiac version & get a Malene Espensen in her tight little nurse outfit for the photo's  :cup:
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 03, 2012, 04:34:18 PM
Its interesting so far, all 3 two litre plastic bottles have been in the freezer now for about 36 hours.

All 3 are "nearly" frozen solid, which is what i was hoping for. By Friday morning when we leave and remove them from the freezer, i'm thinking/hoping, i'll have 3 solid bricks.

Be interesting to see how they last too, as they are in the beer and coke esky only and i'm planning on throwing a wet towel over the esky lid during the day.

Title: Re: A Serious Question.... about ice, yep...ice.
Post by: edz on September 03, 2012, 05:21:32 PM
Just dont do like a bloke at work did, He froze down three tubs of salted brine and put the block ice into his custom esky.with party ice over the top .
All was great......... at first....... till the ice melted down and the cans where bobbing in the melt water / ice slush.. then all he could taste was salt every time they tried to drink from the cans, he reckoned even wiping the can first didnt help .
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: jclures on September 03, 2012, 08:56:06 PM
We used to make ice for sale, if it was for a fishing trip or alike, we always added salt to the water before freezing, I always seemed to last longer with the salt, but it took longer to freeze down before using.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Mallory Black on September 04, 2012, 07:42:10 PM
I had a go earlier this year but my freezer didn't have the grunt to freeze salty water.
It was awesome to see whenever I took the container out and watched the condensation on the outside freezing, so that proved it was damn cold but in the esky I had no way of telling how cold it was after a day or so.
So went back to just using clean soft drink bottles with frozen tap water in them, if there was ice in it it was cold enough to chill stuff, when there was no more ice it became drinking water.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Trex_s4m1 on September 04, 2012, 09:37:03 PM
how long do you need to go away for?
i have been using techniice ice boxes and dry ice sheets (reusable) for a few years now and they are great. pack smart and they last ages.
also they lower your freezer temp by a few degrees so you save on the freezer running costs ;)
i have an 80L and 100L 80 is prob enough but the 100 is good for parties to fill her up with drinks.
hth
sam
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Burnsy on September 04, 2012, 10:40:35 PM
Correct that salt water needs to be colder to freeze (by around 4 degrees as Steve suggests) however it really should make no difference.  If you have two 5kg blocks of ice both at say minus 10 degrees, whether they have salt in them or not should make no difference as they have the same thermal energy, ie 5kg at minus 10 degrees.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: SteveandViv on September 05, 2012, 12:16:01 AM
Correct that salt water needs to be colder to freeze (by around 4 degrees as Steve suggests) however it really should make no difference.  If you have two 5kg blocks of ice both at say minus 10 degrees, whether they have salt in them or not should make no difference as they have the same thermal energy, ie 5kg at minus 10 degrees.

Yes and I for got to add which has been already that the salt verse water concentration is very high. Not like a few cups of salt per whatever of water but at a level that is considered a brine. This is also used in fishing as the brine solution is not soaked up as much as a pure water solution meaning when the fish is frozen does not turn into mush when re-thawed from cell damage. (wonderful thing doing a 4 year apprenticeship as a Chef, they teach you all kinds of Paku )
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Burnsy on September 05, 2012, 11:37:38 AM
The chef and the scientist, what a fine team we make :laugh:

So to sum up for the OP

Saline water has a lower freezing point but no additional ability to store thermal energy, as such, 2kg of non saline ice and 2kg of saline ice both at the same starting temperature (ie frozen in the same freezer for the same amount of time) should take the same amount of warm beer and time to bring the entire mix up to say 5 degrees.

There may be some minor variances such as if you take beer out along the way, for example as the ice slurry will be colder it may cause the beer to part freeze so when you remove a beer you will be removing a greater amount of thermal energy than if you remove a beer from the non saline esky.  Removing a greater amount of cold thermal energy each time in this manner will actually make the saline esky come up to the higher temperature quicker than the non saline. 
Title: A Serious Question.... about ice, yep...ice.
Post by: ozbogwam on September 05, 2012, 12:18:54 PM
Just use dry ice much easier and cleaner. We used to use it prior to the Waeco.

Would get a shovel full from BOC and make an inch or so layer on the bottom of the esky. Then a layer of newspaper and a tea towel on top then all the pre chilled food.

Then we'd grab a six can esky and fill it with dry ice. We would use this to chill our drinks in cans. They would be stored out of the esky then just grab one place on top of the dry ice and just rotate it around on the ice for a minute or two and nice cold drink.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Patr80l on September 05, 2012, 12:46:36 PM
or you could add sawdust.

http://en.wikipedia.org/wiki/Pykrete (http://en.wikipedia.org/wiki/Pykrete)
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: SteveandViv on September 05, 2012, 08:21:46 PM
The chef and the scientist, what a fine team we make :laugh:

So to sum up for the OP

Saline water has a lower freezing point but no additional ability to store thermal energy, as such, 2kg of non saline ice and 2kg of saline ice both at the same starting temperature (ie frozen in the same freezer for the same amount of time) should take the same amount of warm beer and time to bring the entire mix up to say 5 degrees.

There may be some minor variances such as if you take beer out along the way, for example as the ice slurry will be colder it may cause the beer to part freeze so when you remove a beer you will be removing a greater amount of thermal energy than if you remove a beer from the non saline esky.  Removing a greater amount of cold thermal energy each time in this manner will actually make the saline esky come up to the higher temperature quicker than the non saline.

To right Burnsy ;D
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 06, 2012, 05:32:47 AM
The freezer in the shed must be ok.

All 3 two litre bottles are frozen like a rock. So i'll chuck the drinks in around them, then some party ice to take up the gaps.
I've kept the salted ice in bottles so it won't effect anything that might get put in the esky.

The forecast for tomorrow is 29 degrees, so once the campsite is set up, we can both sit back and enjoy a coldie.... or 4.

Only one more sleep now, by this time tomorrow (5:30am) we'll be starting off on the big haul (1/2 an hour) to Inskip Pt.

Anyway, it will be interesting to see how some party ice lives, however, i'll bung it in the freezer overnight to get it frozen.
Those party ice fridges are only a hair off having cold water from ice.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: LB on September 06, 2012, 05:42:28 AM
Appologies if someone has already answered this. How much salt do you add?

Plus we used to freeze 2 ltr bottle but found that 2 ltr ice cream containers took longer to melt (have come home from a 5 day camp and still had ice in our tropical Ice box). We put a freezer bag in the ice cream container then the water. Every couple of days leading up to a camp we take the freezer bags out put it back in the freezer then do it all again. Before putting them in the esky we triple freezer bag so they don't leak.

LB
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 06, 2012, 06:12:16 AM
Mate, i had one off them big table salt containers and just up ended it with the big hole open. (the salt thing, not mine)

I just poured it in until the colour of the water is the same as lemon cordial.

Now, after i'd done it all and wacked ém in freezer, i thought i should have used a measured amount so i could repeat it.

I did remove the bottles every 12 hours from the freezer and shake the bejesus out of ém to keep the salt mixed up etc.

Next time i will measure the amount, but i'm guessing, maybe 5 or 6 tablespoons of it in each.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: jclures on September 06, 2012, 07:01:29 AM
I could be wrong as usual, but I am a believer the bigger the block the better the ice will keep. My reasoning for this is small blocks, i.e. milk bottles have a grater surface area so the ice melts quicker than a large solid block.
My block mould has around 10 litres of water, I know it is a little larger than the commercial blocks I see up here anyhow.
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Alan Loy on September 06, 2012, 11:47:49 AM
Quote
So to sum up for the OP

Saline water has a lower freezing point but no additional ability to store thermal energy, as such, 2kg of non saline ice and 2kg of saline ice both at the same starting temperature (ie frozen in the same freezer for the same amount of time) should take the same amount of warm beer and time to bring the entire mix up to say 5 degrees.
Quote

If Burnsy is right I have just wasted my time adding salt to the water to make blocks.  Does everyone agree that fresh water works just as good as salt water for the esky ice?
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Bird on September 06, 2012, 12:59:11 PM
Quote from: ozbogwam
Just use dry ice much easier and cleaner. We used to use it prior to the Waeco.

Would get a shovel full from BOC and make an inch or so layer on the bottom of the esky. Then a layer of newspaper and a tea towel on top then all the pre chilled food.
thats interesting, when I went to buy some Dry Ice from joint in Dande befor our Flinders trip (using techni-ice boxesw), the bloke told me not to bother as it would freeze everything solid being -75c and all
He had had plenty of people come back complaining of their steaks being titanium hard days later. He gave me a cup full and said go try it and see what you think...
Didnt bother.. used Techni-ice sheets, and they were Shit too :(
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 06, 2012, 02:38:01 PM
I tried some techni ice sheets a few years ago when we did the house boat thing up the straits.

The bloke in Gympie wouldn't or couldn't sell me dry ice 2 years ago, as he reckoned folks were burning themselves with the dry ice.

I've never been a fan of the techni ice, but it did keep $50.00 of Cold Rock Ice Cream ok until we got it in the freezer on the house boat.

Thats a good holiday too, get a house boat out of Tin Can Bay..... :cup:

We had 6 of us on a 54 foot house boat, 3 tenders off the back, the works.......
It's funny ya know, it was standing on the upper deck of the house boat on that trip when i said to Mrs. Jeepers, ya wanna sell up and move to Tin Can?

Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Hefty on September 07, 2012, 12:28:05 AM
Appologies if someone has already answered this. How much salt do you add?

Plus we used to freeze 2 ltr bottle but found that 2 ltr ice cream containers took longer to melt (have come home from a 5 day camp and still had ice in our tropical Ice box). We put a freezer bag in the ice cream container then the water. Every couple of days leading up to a camp we take the freezer bags out put it back in the freezer then do it all again. Before putting them in the esky we triple freezer bag so they don't leak.

LB

I researched this at the end of last year and have been using them ever since.
I think I used this site http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/meltpt.html (http://hyperphysics.phy-astr.gsu.edu/hbase/chemical/meltpt.html) to figure it out and went with 15% by weight to get approx -10 degrees C. I use 3L juice bottle and kitchen scales. My freezer can just handle the 20% -16 but it takes a lot longer to get a good hard block.
In my researching I came to pretty much the same conclusion as Burnsy but I still use them along with pure water ones to give me a rough idea of temp. Eg, Ice in salt bottles and pure water bottles approx -10. Water in salt bottles, ice in pure water bottles between -10 and zero (I approximate by how much salt ice is melted). Water in both, above zero degrees.
Then you just have to make sure the salt ice bottles are clearly marked so you don't try to use them for drinking water once they melt!!
I've started to avoid the salt ice on weekend trips because all it does in that space of time is refreeze stuff.

Cheers!
Jono.
Title: A Serious Question.... about ice, yep...ice.
Post by: ozbogwam on September 07, 2012, 07:29:39 AM
thats interesting, when I went to buy some Dry Ice from joint in Dande befor our Flinders trip (using techni-ice boxesw), the bloke told me not to bother as it would freeze everything solid being -75c and all
He had had plenty of people come back complaining of their steaks being titanium hard days later. He gave me a cup full and said go try it and see what you think...
Didnt bother.. used Techni-ice sheets, and they were **** too :(

Yeah you need to be careful not to use too much and make sure your food isn't in direct contact with it hence the newspaper/tea towel barrier.

We used it for a week trip in summer in hot weather and it worked really well
Title: Re: A Serious Question.... about ice, yep...ice.
Post by: Jeepers Creepers on September 12, 2012, 06:50:14 PM
well, the iced salty stuff did work better than normal ice, IMHO.

I threw some party ice in with it before leaving home and for the first few days, the beers were that really nice, icey cold.

By day three, i was throwing one bag of party stuff in each day, but think it went better than normal ice.
The beer was still nice and icey cold....
But lets face, when you've dicked around to try something new, you always think it works better, its human nature.

I will do it again, but next time, i'll measure the salt amount and try for a more confirmed idea if its worth the rooting around.