Refractometer testing propylene glycol ANT

[oilboy123]

So I just did 2 Fords with Amsoil ANT coolant. Propylene glycol. I have close to 50% in both vehicles. I flushed original Ford orange out of the 2016 Focus Duratech. I also had orange unknown brand coolant in the 2012 F150 Duratech. The truck has 213K, Focus 106K.


I bought a refractometer cheapo from Amazon in 2021. I just tried it out on both vehicles. I did the calibration with distilled water to zero it. I get about -45C testing a very close to 50 50 mix of the antifreeze unused with the refractometer.

The coolant jug says I should be at 34C with 50 50 mix. I also used an old Sierra small glass tester with 5 little colored balls. It says 4 balls -40F with the same jug. The Sierra tester shows close to the same on the Focus coolant bottle.

When I test the truck, or car, I don't show a blue hue in refractometer on both of them. Both vehicles should be real close to 50 50. I did a pretty clean change over to the yellow Amsoil from the orange. So I doubt I had more than 1% of old coolant after changing over.

I don't understand why both vehicles with very fresh coolant do not show the blue hue. But it shows well with water and the coolant that has been mixed, but not run in a vehicle?

Thoughts are appreciated

 

[JohnnyG]

Maybe the plate that flips down on the mixture isn't closing completely, or is warped. I've had small dust particles leave a small uncovered area, but after cleaning it showed bluish tone.

 

[oilboy123]

I clean it thourogly, and it closes completely. It also has a double floppy hinge with a ton of play. I make sure it is filled with fluid, and tested things 2 times. I'm stumped.

I told the seller. I'll see what they say. But they probably won't be of any help. But sometimes I'm surprised..........

 

[JohnnyG]

Sounds like the same model I have. If you use the water to calibrate, does it give the blue color?
Very strange.

 

[Chris142]

I have found that the long life coolants don't read right with a refractometer. That or every car I ever tested had too much coolant vs water.

 

[oilboy123]

Sounds like the same model I have. If you use the water to calibrate, does it give the blue color?
Very strange.
View attachment 269338

Yes exact same as that.
The refractometer reads blue, and zeros on the line with white below it. Using distilled water. It reads -40 showing blue with the virgin coolant/distilled water. But no blue whatsoever with the 2 vehicles that have the coolant installed. They each had multiple fills of the Distilled water before adding ANT concentrate.

When I finally filled the 2 vehicle systems. I drained both of the systems with distilled water the last time. There was barely any color on the water as far as old coolant was concerned. It is just weird how the same mixture that was not run in the system reads close to the value on the refractometer. I am very close to 50% coolant/water on both systems. The truck has been running for about 4 months. The Focus about 1 1/2 months.

The old Sierra ball tester shows 4 balls floating on both vehicles. As well as the remaining partial jug of concentrate I made into 50% by adding distilled water. 4 balls is supposed to be -40F on the side of the tester. I think it reads a little low. I think it should be reading closer to -28F.
The refractometer with the virgin coolant/antifreeze mix reads -45C. I think that should be closer to 34C. The Refractometer only reads C, the Sierra ball tester only reads F.

 

[doitmyself]

Yes exact same as that.
The refractometer reads blue, and zeros on the line with white below it. Using distilled water. It reads -40 showing blue with the virgin coolant/distilled water. But no blue whatsoever with the 2 vehicles that have the coolant installed. They each had multiple fills of the Distilled water before adding ANT concentrate.

When I finally filled the 2 vehicle systems. I drained both of the systems with distilled water the last time. There was barely any color on the water as far as old coolant was concerned. It is just weird how the same mixture that was not run in the system reads close to the value on the refractometer. I am very close to 50% coolant/water on both systems. The truck has been running for about 4 months. The Focus about 1 1/2 months.

The old Sierra ball tester shows 4 balls floating on both vehicles. As well as the remaining partial jug of concentrate I made into 50% by adding distilled water. 4 balls is supposed to be -40F on the side of the tester. I think it reads a little low. I think it should be reading closer to -28F.
The refractometer with the virgin coolant/antifreeze mix reads -45C. I think that should be closer to 34C. The Refractometer only reads C, the Sierra ball tester only reads F.

From this site: https://www.f1technical.net/forum/viewtopic.php?t=28740
By diluting the propylene glycol 50/50 (water), ........ the freezing point of -32.2 ° C (-26 ° F).

By diluting propylene glycol to 60/40(water) the frost protection drops to -51 ° C (-60 ° F).

My interpolation: 54% propylene glycol/46% water = your -40C reading.

I have an expensive, temperature compensated coolant refractometer at work. I use a graduated pipette to achieve an accurate 50/50 mix for checking meter accuracy/precision. It takes VERY little mixing error to achieve a significant meter reading change. Casually hand mixing distilled water with coolant concentrate could easily result in your -40C reading.

Why your meter won't read the in-use coolant. It's anyone's guess. Some Googling suggests that there might be some sort of contamination (oil, etc.). The optics in these are quite sensitive.

Only a miniscule % of Amazon reviews are negative, but it might be possible you have a bad one if this is your first use of it.

Can you get some in-use coolant from another trusted source for comparison? My meter measures long life ethylene glycol fine. I don't have any polypropylene to test.

 

[JohnnyG]

Here's the view through my refractometer. It's dry in this case, but anyway, if you look carefully (sorry for the bad pic) down at the very bottom is a small F for farenheit. Also the left is labeled Etheylene Glycol and the right side is labeled Propolene Glycol.

 

[oilboy123]

"doitmyself" I think you might have my answer.....

What you wrote:
"Why your meter won't read the in-use coolant. It's anyone's guess. Some Googling suggests that there might be some sort of contamination (oil, etc.). The optics in these are quite sensitive."

I did replace the 2 rad hoses on the Focus, and all the hoses on the F150. When I did I put a small amount of silicone grease on the hose fittings male. Not much in fact. Wiped just enough to get into the pores of the metal, or plastic. So I don't have welded hoses. Maybe just enough to contaminate, and throw off the readings with the refractometer.

I don't see an oil slick or anything like that. This hypothesis makes sense. Thanks