Antifreeze question

Posted by: Plumber

Antifreeze question - 01/04/14 10:02 PM

Prestone antifreeze tester says the liquid is rated to -15 degrees. Is this when it actually freezes solid, or gets slushy?
Posted by: Donald

Re: Antifreeze question - 01/04/14 10:11 PM

I would put a little in a Dixie and see how it does at 0F which is what your freezer should be.
Posted by: Kuato

Re: Antifreeze question - 01/05/14 12:13 AM

Considering the precision of those testers, err on the safe side and figure it will eventually freeze at -15, with the normal transition from liquid to slush to soft ice to hard frozen.

If you have the chance and location, maybe a radiator drain and refill with 100% coolant is in order. (Adjusted for system capacity)
Posted by: crazyoildude

Re: Antifreeze question - 01/05/14 12:51 AM

100% coolant? Never a good idea Never! 50/50
Posted by: KitaCam

Re: Antifreeze question - 01/05/14 03:31 AM

Originally Posted By: crazyoildude
100% coolant? Never a good idea Never! 50/50


Yes! 50-50 is good to -34F (I think that's about -37C)
Posted by: shDK

Re: Antifreeze question - 01/05/14 03:49 AM

Originally Posted By: crazyoildude
100% coolant? Never a good idea Never! 50/50


perhaps the guy meant he should drain a bit of the coolant in the system. maybe a litre, and then refill with concentrated coolant. To adjust the freezing point. i think that what what he meant.
Posted by: NHGUY

Re: Antifreeze question - 01/05/14 07:25 AM

100% will freeze.Water is the carrier of thermal conductivity.
Posted by: JHZR2

Re: Antifreeze question - 01/05/14 08:41 AM

Slush and solid is just a matter of time. The differentiation is thermal mass (how much heat the engine block retains.

You could make a practical assessment of how often and for how long is the temperature actually -15? Maybe not long or never.

Still, to me that means your as is a little light, as it still gets quite cold in IL. I'd just siphon a small amount of your current AF and replace it with neat AF and call it a day. You can do a calculation to determine how much you need, and you definitely don't want to get too much glycol in there, but you should add some.
Posted by: Plumber

Re: Antifreeze question - 01/05/14 09:35 AM

Severe cold is hitting tonight. I plan on warming up the 54, then dilute some more antifreeze.

A month ago I figured -15 would be fine! Ugh....
Posted by: doitmyself

Re: Antifreeze question - 01/05/14 11:15 AM

My Prestone antifreeze tester pictured below turned out to be incorrect.

Try to find a shop that has a refractometer to test your juice. It takes less than 5 minutes time.
Posted by: Plumber

Re: Antifreeze question - 01/05/14 12:27 PM

I just got back from the yard. The beater 54 took 5 cranks to start, I let it run for 30 minutes, added about a gallon of 60/40 and let it run another 10 minutes. My biggest gripe would be a cat or critter making a home on the warm engine!

Running a 5w-30 National brand oil, and a blue bottle of STP...sounded great upon start up! Not bad for a 230 flathead from 1954 in bad temps!
Posted by: Kuato

Re: Antifreeze question - 01/05/14 03:51 PM

Originally Posted By: shDK
Originally Posted By: crazyoildude
100% coolant? Never a good idea Never! 50/50


perhaps the guy meant he should drain a bit of the coolant in the system. maybe a litre, and then refill with concentrated coolant. To adjust the freezing point. i think that what what he meant.



Precisely. I wish people would read for content.

I said, "radiator drain and refill...adjusted for capacity". We don't need to do the math for OP but an adjustment from the current protection to a 50/50 situation would be a good idea.

And to be fair I should have said to adjust to 50/50 in the first post.
Posted by: Jiblet

Re: Antifreeze question - 01/05/14 08:36 PM

Originally Posted By: doitmyself
My Prestone antifreeze tester pictured below turned out to be incorrect.

Try to find a shop that has a refractometer to test your juice. It takes less than 5 minutes time.


A decent coolant refractometer can be bought for around $25.

Those floating ball things are worse than useless.
Posted by: crazyoildude

Re: Antifreeze question - 01/05/14 11:00 PM

we use those exact type testers and have no issues with them
Posted by: Wilhelm_D

Re: Antifreeze question - 01/06/14 07:30 AM

Originally Posted By: Kuato
If you have the chance and location, maybe a radiator drain and refill with 100% coolant is in order. (Adjusted for system capacity)


100% ethylene glycol would result in protection to about 10 F.

That's the freezing point of pure ethylene glycol, but when you mix ethylene glyclol with water, the mixture does not readily crystallize and the freezing point of the mixture is depressed. So a mixture with water is better than pure antifreeze.

The other problem pure ethylene glycol presents is that it does not transfer heat as well as water. For a cooling system with pure ethylene glycol the circulated volume must be increased compared to a system with clean water alone.

Ethylene Glycol Heat-Transfer Fluid

The optimum mix for antifreeze purposes is about 2/3 ethylene glycol to 1/3 water.
Posted by: Kestas

Re: Antifreeze question - 01/06/14 11:00 AM

Here is the protection chart:



My know-it-all friend in college once used pure antifreeze in his 65 Ford. Shortly afterward it blew a head gasket, leaving a cloud of white smoke behind the car.
Posted by: Boss302fan

Re: Antifreeze question - 01/06/14 11:44 AM

60/40 will get you in the mid -40's and that is the most concentrated coolant I would go with.