How to remove hardened water spots from auto mirrors & glass

If you live in an area with hard water, you might notice water spots on your automobile mirrors and glass. Hard water spots are caused by excessive minerals and deposits in your water. Whether from a sprinkler hitting your car, or from washing your car and not drying it thoroughly, hard water spots are unsightly and can inhibit your ability to see clearly out of your automobile windows and mirrors.

Fill a clean, empty spray bottle with a solution of 1 part water and 2 parts vinegar. If the spots are severe, use undiluted vinegar.

Spray the vinegar onto the hard water spots. Let it sit for five minutes.

Scrub the windows and mirrors with wet paper towels to remove the vinegar and the water spots. Dry thoroughly with clean paper towels or a soft rag.

Make a paste of 3 parts baking soda and 1 part vinegar if the spots persist. Use a sponge to scrub the paste onto the glass. Let it sit for 5 to 10 minutes, then rinse with clean water. Dry the windows thoroughly with paper towels or a soft rag.


Mix a solution of 3 tbsp trisodium phosphate and 1 gallon of hot water for another way to remove hard water spots. Scrub the windows with a sponge and the cleaning solution. Rinse and dry the glass thoroughly. Lemon juice can also be used to remove hardened water spots. Spray the lemon juice onto the glass, let it sit for five minutes, then scrub with wet paper towels. Dry the glass thoroughly with clean paper towels.

Things You'll Need

  • Spray bottle
  • Water
  • White vinegar
  • Paper towels
  • Rags
  • Baking soda
  • Sponge
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About the Author

Kimbry Parker has been writing since 1998 and has published content on various websites. Parker has experience writing on a variety of topics such as health, parenting, home improvement and decorating. She is a graduate of Purdue University with a Bachelor of Arts in organizational communication.