Trouble using a refractometer for windshield washer fluid

[Kestas]

I just bought a refractometer to upgrade from floating balls. Calibration with distilled water was spot on, right out of the box. It also reads spot on for coolant strength, using control samples (virgin antifreeze, and 50-50 strength), which is good. But when I go to measure windshield washer fluid, the readings make no sense. Below is a snapshot of virgin washer fluid, right out of the jug, specified as good to -25°F. I have two jugs (different brands) and they show the same thing. Am I missing something here? Is it operator error? I'm inclined to just make a mental note that this is the line for proper strength. Also, why are there two scales for washer fluid, right and left? What is SRF1? I haven't yet tried battery fluid.

 

[JohnnyG]

That's a nice one! However SRF1 uses Isopropyl alcohol, and if your fluid uses methanol or something else, it may not work correctly. If that left column for washer fluid is for methanol or not it really doesn't say.

It's also very possible that the mixture doesn't meet the statement on the bottle. +15° F looks like some kind of summer fluid or a mixture of summer/winter stuff.
Just from personal experience, I'v never had a washer fluid remain liquid at -25 without adding extra alcohol. Engine compartment bottle, sure, but sprayed on the windshield, forget it!

As far as glycol antifreeze concentrations, I'd much rather see percentages than just a temperature reading.

 

[97prizm]

I think methanol won't show up correctly

 

[Kestas]

It's also very possible that the mixture doesn't meet the statement on the bottle. +15° F looks like some kind of summer fluid or a mixture of summer/winter stuff.
Just from personal experience, I've never had a washer fluid remain liquid at -25 without adding extra alcohol. Engine compartment bottle, sure, but sprayed on the windshield, forget it!

I'll double check the virgin fluid using my freezer overnight.

As far as spraying on the windshield, winter fluid only works on a warm windshield. The alcohol component evaporates quickly when spread by the wiper.

 

[97prizm]

I'll double check the virgin fluid using my freezer overnight.

As far as spraying on the windshield, winter fluid only works on a warm windshield. The alcohol component evaporates quickly when spread by the wiper.

Thats why I use the yellow Prestone washer fluid. It has re-freeze protection and clears very well. It was -14f last February driving home and that was without wind chill.

 

[JohnnyG]

I'll double check the virgin fluid using my freezer overnight.

As far as spraying on the windshield, winter fluid only works on a warm windshield. The alcohol component evaporates quickly when spread by the wiper.

That seems to explain why it doesn't freeze in the under hood reservoir at least.

 

[JohnnyG]

On a side note, 50% concentration of ethylene glycol is -35° F.

 

[Reggaemon]

Did you try to see what the washer fluid was using your old 2 ball device?
I've never tried using my refractometer for washer fluid. I just trusted the label.

 

[bruce381]

different fluids and solution "refract" at different angles and give differing readings not knowing what the washer fluid (type or brand) and even if it is real in that some say winter are NOT. So not knowing what was used you will have to "windage" calibrate your readings to what you want. water will always be none or zero.

 

[edhackett]

As far as spraying on the windshield, winter fluid only works on a warm windshield. The alcohol component evaporates quickly when spread by the wiper.

The heat of vaporization cools the liquid also, exacerbating the freezing on the windshield issue.

Ed

 

[Kestas]

Did you try to see what the washer fluid was using your old 2 ball device?
I've never tried using my refractometer for washer fluid. I just trusted the label.

No, I didin't bother to test it with the floating ball device. The alcohol is different from antifreeze.
I sometimes use water only for summer use. This device could come in handy to avoid confusion during season changes.

 

[Kestas]

I found my answer. It seems these mixtures are popular in Europe.

 

[JohnnyG]

I found my answer. It seems these mixtures are popular in Europe.

View attachment 340565

I don't think that fully explains the discrepancy.

 

[robbobster]

JFC now I need to mind-eff my washer fluid…

 

[Kestas]

I don't think that fully explains the discrepancy.

The discrepancy is that I was measuring a methanol-based washer fluid with a refractometer that is calibrated for ethanol-and isopropanol-based washer fluids.

 

[JohnnyG]

The discrepancy is that I was measuring a methanol-based washer fluid with a refractometer calibrated for ethanol-and isopropanol-based washer fluids.

Got it!

What did the bead tester show?