What Can I Put on a Window to Stop the Crack From Spreading?

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A small crack in a window may not seem like a major issue, but a small crack that's ignored is likely to spread. The best course of action depends on whether you intend to get the window professionally repaired or do it yourself.

What Causes Spreading?

Numerous factors can cause a small crack in a window to spread. Extreme hot or cold temperatures on either side of the window may make a crack spread, as well as objects hitting the window. Since a small crack weakens the structure of the window, the window does not require a direct hit in order to crack. With a car window, any jostling of the vehicle, such as hitting bumps, may cause the crack to spread.

Temporary Fixes

You can use several temporary materials to prevent a crack from spreading until you apply a more permanent repair. To simply keep dirt out of the crack, clean the area around the crack with rubbing alcohol, let the alcohol dry and put a piece of transparent tape over the crack. Alternately, apply a thin layer of clear fingernail polish over the crack to provide a temporary fix.

Permanent Fixes

Cracks shorter than 12 inches in length and chips smaller than a quarter in diameter can be permanently repaired. Call a professional or purchase a windshield repair kit and follow the directions carefully. Before making the repair, you must remove the temporary fix, such as scraping out the fingernail polish, and use the suction device included to ensure that the crack gets completely filled.

Larger Cracks and Chips

Cracks longer than 12 inches or chips larger than a quarter cannot be repaired; you must replace the entire pane of glass. To prevent a crack in a windshield from spreading and obstructing your view as you drive, consider calling a service that will travel to your location.


Alexis Lawrence

Alexis Lawrence is a freelance writer, filmmaker and photographer with extensive experience in digital video, book publishing and graphic design. An avid traveler, Lawrence has visited at least 10 cities on each inhabitable continent. She has attended several universities and holds a Bachelor of Science in English.