Antifreeze Freezing Point?

It hit around -20 a few days back, and to be honest, it's been far too
cold for motorbiking since Jan. However, it has just occurred to me
to wonder would the coolant have frozen at that temperature?

Does anyone know the concentration of antifreeze/water that is
commonly used, cos I guess if they use the 'ideal' proportions it's
good down to -stupid.

Any thoughts?

 

http://letmegooglethatforyou.com/?q=commercial+antifreeze

 

50/50 coolant water

 

Hmm, ok, so, if it was ethylene glycol, which I assume it is, it's off
the 'ideal' point, but still good to minus eek! From

http://www.gi.alaska.edu/ScienceForum/ASF6/680.html

 

My handbook for the car reckons 50 50 mix is good down to minus 20 C

The blucol web site reckons 50 50 mix is good to minus 34

they recomend you never have a concentration higher than 70% antifreeze 30
water

 

Ah, tucked away in the wiki entry. So, depending on wht it is, should
be around -35 then.

 

It was that -20 number I had in the back of my mind. Oh well,
probably find out halfway down an autobahn

 

when servicing my own vehicles I used to use a large syringe to extract
some coolant from the rad. Bung the coolant into a freezer. Leave
overnight. If the coolant was still liquid then I assumed it would be okay
down to whatever nature was going to throw at us. If there was any sign of
crystal/jelly then I simply added a litre of *neat* antifreeze to the rad.
This worked throughout the series of very cold winters we had in the early
1980s.

 

I use a 30-50 mix depending on how much anti freeze I have to hand and
how big the cooling system is.

From what I remember the real killer for cooling systems is not the
static temperature in a garage for a laid up vehicle but the just started
up and being driven wind chill factor through the radiator before the
thermostat has opened fully.

IIRC, the Allegro (or some other BMC thing, the Maxi?) had a feed/bypass
pipe running under the radiator that would freeze and split in fairly
benign temperatures due to windchill.

 

My dad had a Maxi for years. He never had a problem with it freezing. It
got a bit hot when some idiot was driving it and didn't notice the temp
guage in the red. That needed a new water pump. I think it was pure
coincidence that the car needed a new engine within a few weeks.

 

What's the other 20?

 

air: you don't think he has a perfectly sealed system do you?

 

I hadn't noticed my % key's indolent ways until after I'd pressed send.

 

When I lived on the NE coast I had a windchill experience (well, I had
several, but the rest aren't important right now) with my 1965 Humber
Sceptre. The Humber had a tweaked motor from a Hunter GLS and I'd
acquired a hyuuge radiator from somewhere, that had the most beautiful
brass top tank (polished, natch) which had doubled the amount of
coolant in the system and obviated the 'getting a bit warm' tendencies
previously suffered.

It must have been the winter of 1980/81 when it got particularly
chilly. The coolant was 50/50 Bluecol (only the best) and water and I
checked under the bonnet each morning as a matter of routine. This
particular morning it had got down to something like minus ten on the
mercury and it felt distinctly chilly. I popped the bonnet and
squeezed the top hose: Hmm, slightly crunchy but not bad at all,
considering.

I got the thing ticking over while clearing enough glass to see
through, then set off to work. It was only five miles or so, but most
of that was along the Coast Road overlooking the sea, along the tops
of the cliffs, in a half-a-gale. By the time I got to work, the
needle in the temp guage was a bit higher than expected (like, not
lying at the bottom) and there was a bit of steam from under the
bonnet when I parked. Popped the bonnet and all looked well enough.

It froze solid all day and there were shenanigins in the car park,
getting people moving. Frozen-on handbrakes, that sort of thing. The
old Humber seemed all right - coolant level good, still liquid, that
sort of thing.

On the way home the little red needle came up the temp guage, quivered
about a bit, then went down again - then came right back up before
dropping down hard. I knew what that meant - it was trying to read
the temperature of the air in the top housing where the sensor lived.
Bollocks.

It was a little steamy when I got home, so I thought I'd best do
something about it. The top hose was empty, the bottom hose frozen
solid. The radiator was hot to the touch at the top tank (although
bereft of coolant) and damned cold down the core.

After dinner (it was bloody cold by then) I removed the radiator,
noting the weight of the bloody thing, and propped it up in an old
washing-up bowl in front of the fire in the living room. After a
couple of hours the rad was a lot lighter and there was a lot of blue
liquid in the bowl.

My 50/50 Bluecol solution had given up on me. The weatherman on the
box stated a minimum daytime of minus 13, whereas the back of the
Bluecol bottle reckoned 50/50 was good for at least minus 25. Hmm.
That'll be windchill, then.

Having said that, when I reinstalled the radiator early the next
morning there was a patch of blue ice on the already-iced driveway,
culminating in a little blue twisty stalagmite pointing at the engine
block drain tap.

Seven litres of 70/30 Bluecol/water (made with hot water) seemed to
sort it, mind. But that was *bloody* cold that Winter, and the
half-a-gale with inbuilt snow flurries didn't help, not at all. I
took the Old Man's advice after that and installed a radiator blind
made from cardboard.


On a non-numbered footnote - there's a strange thing with antifreeze,
you know. I know it has "seeking" properties, but it has become
painfully obvious to me that if you have a cooling system running on
plain, 'free' tap water (as I often did on the old bangers I ran then,
as water pumps, thermostats and head gasket changes always required
the coolant to be dropped and thrown on the deck) there's nary a leak.

Put expensive antifreeze in the system and the leaks started then.
Every bloody time.

 

That'll be total bollocks, then.
If it's -13C and a gale blows through your radiator, it will still be -13C.
You need to find a different explanation for your problems.

 

eh?

If the temp is, say, -15 and the speed of the vehicle is 60 mph then the
windchill effect on the radiator is -32 Cel.
http://en.wikipedia.org/wiki/File:Windchill_chart.GIF

How the **** do you think car cooling systems work?

 

You learn something new every day !

I guess it's a form of anthropomorphism.

It appears that wind chill on inanimate objects only shortens the time
to cool. The inanimate object will not cool below the actual air
temperature.

 

http://www.weather.gov/os/windchill/windchillglossary.shtml

Item 2.

hth

 

Did you read the article the chart came from?

"Wind chill is the apparent temperature felt on exposed skin"

What that means is if it's -15, but there's a 60 mph wind, then it will
/feel like/ -32. It doesn't mean it's /actually/ -32. See this link from
the same page:

http://weatherquesting.com/wind-chill.htm

Thermal gradient. If the contents of the radiator were at the same
temperature as the surrounding air, then no further cooling would take
place, no matter how fast it was going.

 

See that dot in the distance? That's the point, and you completely
missed it.
The OP said that his radiator froze because it got below -25C when the
ambient temperature was -13C and the wind was passing through it, which
is incorrect. He obviously didn't have as much antifreeze as he thought
so the radiator froze at a higher temperature than -13C.