Prestone Deicer Fluid

[mcboy]

Having just suffered thriugh the first wonter storm of the year I went to Wal-Mart for my fox of Prestone windshield deicer. In the past it has performed MUCH better than any other product that I tried. It contained methanol and ethylene glycol.
They appear to have made a formula change (no more ethylene glycol), they brag about now having dirt blocker technology(silicone).

Does anyone know of a source for a product similar to the old Prestone formula? Or perhaps I can track down some pure ethylene glycol and spike it in a methanol based product.

Prestone tech support did not return 3 calls over 2 days so they eill be no help.

 

[04SpecV]

I got a bottle of the Prestone De-Icer additive to add to my current washer fluid. It says it contains ethylene glycol. I also got a jug of the Prestone deicer fluid which does not contain ethylene glycol.
Doesn't make any sense to me.

 

[labman]

A source of ethylene glycol is as near as your radiator cap. What drips off the cap should be enough for about a gallon fluid. The methanol or even isopropanol will evaporate out of the end of the jet faster than the water leaving the water to freeze. A dab of ethylene glycol will become more concentrated as the alcohol and water evaporate becoming concentrated enough to keep the tip of the jet from freezing.

 

[nobadges]

quote:

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A source of ethylene glycol is as near as your radiator cap. What drips off the cap should be enough for about a gallon fluid. The methanol or even isopropanol will evaporate out of the end of the jet faster than the water leaving the water to freeze. A dab of ethylene glycol will become more concentrated as the alcohol and water evaporate becoming concentrated enough to keep the tip of the jet from freezing.

---

I can't follow what you are saying

 

[glennc]

I bought 4gals of the Prestone stuff a couple months ago, as usual. I noticed the bottle no longer said -34 degrees on it; figured they'd just changed the marketing.

Week or so ago it got cold, and I noticed the fluid freezing up after spraying the windshield. Driving through -7 or so air. Little ice crystals forming on the windshield, couldn't see well... this never happened before.

Then I read this thread.

Dammit! Another once-better-than-anything-else product defused into mediocrity. I already have chosen Zerex over Prestone for coolant-related products, I will now avoid Prestone for all purposes unless there is a compelling reason to go with it. Prestone, you just lost my business.

(By the way I noticed the bottles now say "protects to" -25 degrees, or maybe it was -20.)

Labman, how does a couple drops of ethylene glycol have any affect? I'd like to know how to calculate freezing points of differenct mixes of water, ethylene glycol, methyl alcohol, and whatever other stuff is in the de-icer boost products. I'm sure there's a cheap way to make a good homebrew that won't strip wax, etc. We need some chemistry help here! Let's come up with a formula!

- Glenn

 

[Audity]

Just guessing, but I wouldn't be surprised if glycol was prohibited, for environmental reasons, for use in a total loss system like a windshield washer. Airports are now required to have recovery systems for glycol deicing fluid (volumes are way different, but the principle is the same).

Maybe the additive 04SPECV bought is NOS?

 

[NewGuy]

A common replacement for ethylene glycol is propylene glycol. Ethylene glycol has a sweet taste that attracts animals and is a known to cause kidney damage. Propylene glycol is safe to use in food, but might not have identical freezing point depression properties as ethylene glycol. Historically (back when I was a formulation chemist) ethylene glycol was less expensive, but things might have changed.

I don't know what Prestone is using these days, but I wouldn't consider the absence of ethylene glycol a bad thing without knowing what it was replaced with in the formulation.

You can get some good starting glass cleaner formulations by browsing some of the websites of the major solvent suppliers.

 

[glennc]

The ethylene glycol is still in the Prestone additive at W-M where I live, too.

The blurb on the bottle used to say -34 degree freeze protection, now it says -25 degrees or something - so the product had definitely been made inferior.

I wouldn't be surprised if there were some regulatory reason for it, but I'm still curious what it is, and what I can do to be able to clean my windshield in -xx weather.

- Glenn

 

[Dark Jedi]

I got the prestone with the dirt blocker and it does work good.dont have that dreaded white streak after a few wipes of the blades. I noticed even with the old fomula my window would freeze if I dorve with out the heater warming up.