Homemade windshield washer fluid recipe

Learn how to make your own washer fluid

You can make your own homemade windshield washer fluid using the ingredients listed belowHere are the most common washer fluid ingredients along with a brief description of what each component does:

1: Distilled water. Use distilled water to make your own windshield washer fluid because it doesn’t contain any minerals that can dry and harden on your windshield. Do not use tap water unless you want to be cleaning off water spots later on.

2. Soap, dishwashing detergent, or glass cleaner. You need some type of cleaner to loosen and dissolve the bonds of dirt and bugs from your windshield. Some washer fluid recipes use premixed glass cleaner, but that kind of defeats the purpose of making your own washer fluid.

Most glass cleaners already contain some type of soap, alcohol and vinegar. So why buy it when you can make it yourself?

3. Alcohol. You add alcohol for two reasons; to dissolve sticky substances on the glass and to prevent freezing in cold weather.

Commercial windshield washer fluids use methanol. Methanol is much harder to buy at retail and is more toxic than rubbing alcohol (isopropyl alcohol). Isopropyl alcohol is available in different concentrations:  70%, 91%, and 99%. For killing germs and bacteria, use 70% concentration. It does a better job at killing bacteria than a higher percentage. However, for windshield use, you want the highest concentration. It’ll do a better job at preventing freezing and will dissolve sticky deposits better.

4. Vinegar. Add vinegar to dissolve hard water stains left on the glass from rain, underground sprinklers or road splash.

5. Ammonia. Ammonia is most effective in dissolving grease and oil deposits on your windshield. Those deposits accumulate from bug splatter

Mix your own homemade windshield washer fluid

To make a gallon of windshield washer fluid, mix the following:

3 quarts of distilled water
12-ounces of rubbing alcohol (99% for cold weather)
8-12-ounces of white vinegar
8-ounces of non-sudsy ammonia
1-tablespoon of Dawn dishwashing detergent
10-drops of blue food coloring (just to identify as windshield washer fluid so no one thinks it’s drinkable)

Mix

Stir thoroughly and pour into your windshield washer reservoir and the rest into an empty gallon jug.

Test for freezing and paint compatibility

Put a small amount into your kitchen freezer to make sure it doesn’t freeze or turn into slush. If it does, increase the amount of alcohol.

Next, test a small amount on an inconspicuous portion of your car paint to ensure it’s compatible. Some aftermarket touch-up paints aren’t compatible with ammonia, vinegar, or alcohol.

Vary the mix based on weather and smell

This recipe includes both vinegar and ammonia which give off a powerful smell. I’ve included both because they’re incredibly effective at dissolving bug splatter without leaving streaks. Since you won’t have the same amount of bug splatter in winter you can vary the amounts or even eliminate them from the mix. However, if the smell of ammonia or vinegar bothers you, reduce or eliminate one or both of these components.

In summer, you can reduce the alcohol content since you’re not concerned about freezing.

Just make sure you include some type of soap to loosen the dirt.

©, 2021 Rick Muscoplat