Hi John....
<font color=blue>... what is your formula?</font color=blue>
I haven't really found one yet I'm all that happy with and which for me is cost-effective and convenient. Certainly, in the warmer months, I could be content with straight water...but this didn't really get all of the dust and dirt off without smearing and without requiring spraying the windshield to a considerable degree. I then combined this with a small portion (no more than a 1/4 to 1/2 teaspoon per gallon) of Palmolive dish washing detergent. I never felt that I was able to get this mixture just right and I was always left with a soapy film or residue on the windshield that left its own unique smear mark. I suppose I could have experimented with different brands but......
Some years ago during the winter I ran out of my blue washer fluid most of us purchase in the market and I started experimenting with some cases of old isopropyl rubbing alcohol I had stored in the barn. Some of my mixes were OK....others weren't when I found my fluid canister frozen. This proved more of a detriment than it was worth since I had to remove the canister, thaw and drain it, and then I'm back to square one looking for another correct mixture that was compatible with fluctuating temperature extremes that varied day by day. I've just never found one mixture I was happy with and decided instead to look for those $.50-.75 per gallon sales in the markets. For me, this was the most time-efficient, cost-efficient, and productive way to go.
Another thing for those interested in making their own washer fluid is making sure whatever is used doesn't freeze up in the windshield washer pump. It's easy enough, albeit somewhat time consuming, to remove a fluid canister. It's a bit more difficult to remove and/or thaw out a fluid pump in sub zero temps.
Out of curiousity, I did a quick Google search and came up with the following links that may be useful for your query. First one provides one vendor's specs. The second link is chat room discussion from another forum that deals with home made windshield washer brews.
<A target="_blank" HREF=http://www.douglasproducts.com/commercial/msds_ww.html>Wiper Blue Windshield Fluid Specs</A>
<A target="_blank" HREF=http://pub157.ezboard.com/fthefrugalshopperfrm26.showMessage?topicID=508.topic>Some Home Made Jack and Jill Recipes</A>
Hope all this is helpful in some way.
....Bob
