Claims about using a mixture of vinegar and water to remove ice from a car’s windshield usually hit the Internet every year around the time of the first freeze in mid- to late-autumn and during large severe winter storms. In recent years this advice has been widely spread as information suggesting that spraying vinegar and water (mixed in a 2:1 or 3:1 ratio) will remove ice from an already iced-over windshield; however, the tip originated not as a
Q: I keep my car outdoors at night during the winter. I use one of those cardboards on the windshield, but it still ices and frosts up. What can I do to stop this?
A: Dip a sponge or cloth into a solution of three parts of either white or yellow vinegar to one part of water. The windshield should stay ice-free. Repeat occasionally.
A 1980 “Hints from Heloise” column advocated the same idea:
Looking at the world through cloudy, streaked windows? Clean them with a mixture of vinegar and water. Same with the windshield. Vinegar also helps retard frost on those cold mornings if you pour it on the windshield the night before (three parts cider vinegar to one part water).
As for whether a mixture of vinegar and water will work to remove ice that has already accumulated on a windshield, a number of those who have tried it have found that the concoction doesn’t really seem very effective for that purpose:
The issue of whether this method of ice prevention will indeed pit windshield glass is a matter of contention, with some cautioning it does:
Pour a mixture of vinegar and water on the windshield so that it freezes to the glass before the rain does, thereby preventing ice. Unfortunately, vinegar eats pits into the windshield glass.
However, others assert vinegar is commonly used in glass cleaning solutions and ordinary household vinegar is far too weak a form of acetic acid to produce this sort of damage:
Very few acids will dissolve glass — that’s why they keep them in glass bottles. Does your vinegar bottle look pock-marked?
Windex (and other glass cleaners) are normally 5% ammonia in some sort of volatile solvent, with some detergents and other chemicals. The more environmentally-friendly variants replace the ammonia with acetic acid. A solution of 5% acetic acid (typical white vinegar) isn’t going to hurt anything that 5% ammonia wouldn’t.
Yet others note even if vinegar doesn’t harm windshield glass, it might cause damage to paint, chrome, or other exterior surfaces, so it should be used on automobiles with caution and wiped up promptly if spilled.
In general, we’ve found no consensus about how effective the use of a vinegar-water mixture to remove or prevent windshield ice might be, or whether it carries a potential risk that outweighs its benefits. However, there are a variety of other methods for dealing with windshield ice that motorists can employ, including the use of commercial
ice and frost prevention sprays:
Consumerist. “Three Cheap Recipes for DIY Windshield De-Icers.”
17 January 2009.