Slushy RV antifreeze

[jcschultz01]

It has been -20F or close to that in MN the last couple nights and I happened to look at my bottles of RV antifreeze that are stored in the tunnel of the trailer (stroage but outside).
The unopened bottles of RV antifreeze are solid enough that the bottoms of the gallon jugs are bulged out.
I CAN still squeeze the sides of the gallon jugs (which has not been opened) so the jugs are not frozen solid.

I called the manufacturer and they told me that RV antifreeze will get slushy but not freeze solid. This, the slushy part, was news to me.
I think I will follow the advice of the RV dealer and blow out the lines, fill with RV antifreeze and then blow out the lines again.

BTW, I have two different brands and they are both slushy.

Are there brands that DON'T get slushy? These are both water, ethyl-alcohol, clycerin, propylene glycol and additives.
Comments?????

[Country Campers]

This is the first I have read of this or even heard. I would guess that minus 20 for a couple days would sure do it to most anything. What I have seen years ago when winter camping was that if you pulled a bottle of water out of the cooler, yes it was in the cooler to keep from freezing, and it was below freezing outside I think it was around 10 or so, and when we opened the bottled water it would freeze instantly not sure why.

I would be concerned in your circumstance but I am not sure how much. I would think that if it "slushes" that might be ok, but if there is some point in a line somewhere that freezes solid at an elbow or other fitting that would be an issue. I have used the antifreeze for years with no issues but I do not believe we had minus 20 for a couple days but did have plenty of nights close to that with maybe 10 above the next day. That all said I never left a bottle out to see what it did. A good test that you did but not a good outcome.

Brian

[Jkwilson]

Slushy is fine. What you don’t want is water freezing. Water has a very unusual property in that density decreases when it gets colder. This leads to bizarre things that we consider normal: Bodies of water with ice on top and pipes bursting when water freezes in them.

[Cate&Rob]

jcschultz01

If you read the details on the RV jug or their website, you will find that “slushy” is normal. Most plumbing antifreeze is advertised as -40 or -50 but if you read the fine print it is “will not break a copper pipe” at this temperature. The antifreeze actually begins to crystallize at something like -20C (-4F). This temperature rises quickly if there is any water mixed with the antifreeze. In the boating world, the preferred antifreeze is advertised as -100F. Three times as expensive and still begins to crystallize at something like -30C (-20F). The Pex, hose and plastic fittings will usually survive the “slush” phase of antifreeze. This has been known to loosen a clamped hose connection.

Blowing out the plumbing with air is a false security. The air will pass over the water or antifreeze remaining in the lines and fittings. A low point fitting will still be filled with liquid after the air pressure is removed.

Rob

[Jlawles2]

Back in college we did a chemistry lab where glycol based liquid was tested to the freezing point both diluted and undiluted. I was amazed at how thick and slushy the stuff got but was still "flowing" and the temperature swing that the slushy mixture existed through. I don't remember if diluted or undiluted froze at a lower temperature.

Opening the bottle and getting the instant freeze is a super cooled liquid. The liquid is just below the freezing point at standard conditions but something (like pressure) and the use of a "smooth" storage container decrease the formation of ice crystals. By opening the bottle you inadvertently disturb the liquid starting the instant crystallization process.

Likewise you can do the opposite and create a superheated liquid in the microwave in a coffee cup. That's why they tell people to be careful when taking heated liquids out of the microwave or to refrain from sticking anything into the container as it creates a disruption leading to instant boiling (usually results in majority of the liquid exiting the container).

[RJAPCOK]

RV antifreeze is propylene glycol and it achieves it's maximum antifreeze property when mixed with the proper amount of water. A solution of 60% proplylene glycol and 40% water will lower the freezing temperature of the mixture to -55 degrees F. It is also hygroscopic, that is, it absorbs water into it. So any residual water in the system will actually improve the anti freeze characteristic as long as the water concentration is less than 40%.

Most RV antifreeze is pre-mixed to make it ready to use.

It will freeze to some extent, but will not freeze completely solid.

https://insist2.com/admin/upl/freezi...ene_glycol.pdf

Bob

P.S. I found this data sheet online after I posted this. I thought it was worth sharing.

https://www.splashwash.com/applicati...s_10-22-18.pdf

[Cate&Rob]

Opening the bottle and getting the instant freeze is a super cooled liquid. The liquid is just below the freezing point at standard conditions but something (like pressure) and the use of a "smooth" storage container decrease the formation of ice crystals. By opening the bottle you inadvertently disturb the liquid starting the instant crystallization process..

In Canada this is a beer problem. The whole bottle can go solid when opened. Bin-ther-dun-that .

Rob

[Jlawles2]

Cate&Rob I heard beer does not get cold if stored in the snow. Been there done that also with the beer freezing between the time the cap pops and it reaches your mouth. Looked at it before and after popping the cap and it still froze. We did determine that the ones most likely to freeze up appeared a bit "thick" with the cap on and tipping it slowly to determine if it was still liquid and not solid.

[Yoda]

In Canada this is a beer problem. The whole bottle can go solid when opened. Bin-ther-dun-that .

Rob

Jlawles2

Well we can see the Rob and Joseph have thier priorities in order.. BTW - wont happen with Gin

To the OP Yes I have seen my antifreeze in the slush state. I blow my lines out, then pump the pink stuff in and and let it sit for a while. Then gravity drain everything , leaving all the faucets open - leaves lots of air space for expansion.

[Jlawles2]

Yoda I don't know Keith, I've been in Ft. McMurray when it was MINUS 56F.

At what point does gin freeze?
Pure gin will not freeze unless the temperature goes below -17°F (27°C), so you usually don’t have to worry about storing gin in the freezer.

[Guest]

DW and I have been going outside in the hot tub where ambient temps are running around 12F. I have not seen my drink freeze so far. Didn't even become slushy.

I use the -50F RV antifreeze and now will have to put some outside to see the result.

Jim

[TedS]

As long as the antifreeze stays slushy it will be able to move and not build pipe-bursting pressure. A little air in the plumbing will help by giving space for the antifreeze to move to. Water alone can form a freeze plug and cause the pressure rise in the trapped unfrozen water.

My bourbon seems to tolerate low temperatures.

[NoPeeking]

In my part of southern Canada I've experienced slushy, but never solidified antifreeze. I have never used air to evacuate plumbing based on the purported ability of the pink stuff to help prevent drying and cracking of valve seals, O rings and other bits over long(er) periods of time.

[Canyonlight]

My apologies to jcschultz01 at the outset......trust you are good natured and appreciate the "other fluids" analysis and feedback lol ! Like my cold weather friends have shared, slushy RV winterising fluid has been shared over the years and most often a non issue as others have posted.

Now, I will have to conduct some testing on my craft beer IPAs along with Carol's vinos to determine slushy/freezing points to ensure that I do not jeopardize beverage events !

Thank you guys for bringing this up !

Dan

[Country Campers]

I woke up to minus 17F this morning, it would have been a good night to test the slush effect on the antifreeze but I did not put any out, too darn cold for testing.

Brian