I just added some of that red windshield de-icer to some rain-x washer
fluid.The red stuff contains ethylene glycol.
I've had rain-x turn to slush after it gets out on the windshield.  I'll
post a report when the next icy rain comes through.

John Meeks
'91 Vanagon MV
Northern Michigan

Vanagon Rescue Squad
www.vanagonauts.com

On Thu, Nov 25, 2010 at 6:28 PM, Dave Mcneely <mcneely4@cox.net> wrote:
>
>
> WRT windshield washer fluids, some products are labeled with a freezing
> point, but it looks more like a "claim" than an actual fact.  But, being a
> water/alcohol mix, the freezing point will change over time with
> differential evaporation.  That's one of the reasons that ethanol gave way
> to ethylene glycol as coolant system antifreeze in the 1950s.  Of course, if
> you knew the proportion of alcohol by weight in the windshield washer fluid,
> you could calculate the freezing point depression.
>
> BTW, most of these windshield washer fluids are isopropyl rather than ethyl
> alcohol, I believe, the same as Windex.  Don't drink any.
>
> DMc
>
> David McNeely
>