Volvo Penta coolant freeze point vs. burst temp

saaristo

Petty Officer 2nd Class
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Sep 22, 2017
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190
Hi,
I have purchased 40/60 ready-mixed Volvo Penta green coolant. The package says it's freeze point is -13F. However, since I have a closed cooling type of engine I'm now wondering if it's good to leave it in during the winter since temperatures in my area can go as low as -30F (rarely, but still). So now I'm wondering - does freezing mean it will probably burst something or it means it will start to form crystals or become gel-like or what it means?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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47,304
So you bought a really expensive coolant that sucks. There are two coolant plants in the world, the label and packaging determines cost

At the 40/60 your freeze point is -13. Which means if you live where its colder, your block will bust

Drain some, add pure coolant to get your freeze point to -34 (50/50). Pure glycol freezes at -86f
 

Lou C

Supreme Mariner
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Nov 10, 2002
Messages
11,802
Why on the earth would they sell coolant with a freeze protection so low? Does not make sense, I'd test it first.
Any ethylene glycol coolant mixed at 50/50 would have a freeze protection of -34*F.
If it gets to -30F* in your climate I'd just mix up my own 60/40 to be on the safe side.
 

jerryjerry05

Supreme Mariner
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May 7, 2008
Messages
17,923
Draining and leaving it empty, not a good idea.
Rust forms quicker in the absence of water.

You didn't say anything about winterizing the raw water system?
Use the same or 50-50 in that part too.
 

Lou C

Supreme Mariner
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Nov 10, 2002
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11,802
You should use ethylene glycol in the closed section of the cooling system but if you are going to use af to winterize the raw water side you really should use no tox propylene glycol AF since when you start up the engine in the spring on the water hose it will run out on the ground. For this in your climate (-30f possible low) I’d strongly advise using the expensive -100 bust temp stuff which does not freeze till about -55F. Rigjt now you need to carefully check what’s in your engine and get your freeze protection down to about -45 given your climate
 

saaristo

Petty Officer 2nd Class
Joined
Sep 22, 2017
Messages
190
So my plan is to purchase VP concentrate and mix it into the already purchased ready-mix to get the concentration close to 50/50, which should be good down to ~28...30F.
Interestingly enough, I found a charts on some web pages stating that ethylen glycol based 40/60 coolants freeze point is -13F, but the burst point is -60F...which is when the hell freezes over:) So I don't know what to make out of it?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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I wouldnt trust anything except air...... freezes at -461F
 

muc

"Retired" Association of Marine Technicians...
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Jul 7, 2004
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2,064
You will be fine as long as you don't try to start the engine while it is below -13° F
 
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