How To Stop Windshield Crack From Running

Finding a crack in your windshield can be incredibly frustrating. Not only does it obstruct your view, but it also poses a safety risk. The biggest concern for most drivers is, "How do I stop this crack from getting worse?" That's exactly what we're going to address here. I'm going to walk you through the steps you can take to mitigate the damage and prevent that crack from spreading further.

Understanding Why Windshield Cracks Spread

Before we dive into solutions, it's important to understand why windshield cracks tend to run. Your windshield is made of laminated safety glass, consisting of two layers of glass with a layer of vinyl in between. When something strikes the windshield with enough force, it typically only damages the outer layer of glass. However, the structural integrity is compromised, making it vulnerable to stress. Several factors can exacerbate this vulnerability:

Temperature Fluctuations: Extreme heat or cold causes the glass to expand and contract. This constant movement puts stress on the existing crack, causing it to lengthen.
Bumps and Vibrations: Driving over rough roads or even just the normal vibrations of your car can put pressure on the weakened area around the crack.
Air Pressure: Changes in air pressure, such as driving at high altitudes or even going through a car wash, can also contribute to the crack spreading.
Moisture: Water that seeps into the crack can freeze and expand in cold weather, exerting force that extends the damage.

Immediate Actions to Take

The moment you notice a crack, the clock starts ticking. The faster you act, the better your chances of preventing further damage. Here’s what you should do immediately:

1. Clean the Area

Use a clean, dry cloth to gently wipe the area around the crack. Remove any dirt, debris, or loose glass fragments. This will allow any repair materials to adhere properly. Avoid using harsh chemicals or abrasive cleaners, as these can further damage the glass.

2. Apply Clear Packing Tape

This is a simple but effective temporary fix. Use clear packing tape (the wider the better) to cover the crack, both on the inside and outside of the windshield. Make sure the tape is smooth and adheres firmly to the glass. This will help prevent dirt and moisture from entering the crack and will provide some structural support.

Important: Use clear packing tape. Colored or opaque tape will obstruct your view and could be a safety hazard.

3. Avoid Extreme Temperatures

As mentioned earlier, temperature fluctuations are a major cause of crack propagation. Park your car in a garage or shaded area to minimize exposure to direct sunlight. Avoid using your defroster or air conditioner directly on the windshield, as the sudden temperature change can worsen the crack.

4. Drive Carefully

Avoid driving over rough roads or potholes, as these can put stress on the windshield. Drive smoothly and avoid sudden acceleration or braking. Be mindful of speed bumps and other road hazards.

DIY Crack Prevention and Repair (Short-Term Solutions)

While a professional repair is always recommended, there are some DIY options you can try to slow down or even stop the crack from spreading. However, keep in mind that these are temporary solutions and do not replace a proper repair or replacement.

1. Windshield Repair Kits

These kits are readily available at most auto parts stores and online retailers. They typically include a resin solution that is injected into the crack to fill it and bond the glass together. Here's a general overview of the process:

Clean the crack: As before, make sure the area around the crack is clean and dry.
Apply the applicator: Follow the instructions included with the kit to attach the applicator to the windshield over the crack.
Inject the resin: Carefully inject the resin into the crack, making sure it fills the entire length.
Cure the resin: Most kits use UV light to cure the resin. Place the included UV light or a UV lamp over the repair area for the recommended time.
Remove excess resin: Once the resin is cured, remove the applicator and scrape away any excess resin with a razor blade.

Tools Needed: Windshield repair kit (includes resin, applicator, and UV light), clean cloth, razor blade. Approximate Cost: $10 - $30

Important Considerations: These kits work best on small chips and cracks (typically less than 12 inches long). They may not be effective on long or complex cracks. Always follow the instructions included with the kit carefully.

2. Super Glue (Emergency Use Only)

In a pinch, you can use super glue to temporarily seal the crack and prevent moisture from entering. Apply a thin layer of super glue along the length of the crack, making sure to get it into the crack as much as possible. Wipe away any excess glue with a clean cloth.

Warning: This is a very temporary solution and should only be used in emergencies. Super glue can sometimes discolor the glass and may make a professional repair more difficult. It’s really just to prevent further immediate cracking before a more permanent solution is found.

Professional Repair vs. Replacement

The best course of action depends on the size, location, and severity of the crack. As a general rule:

Small Chips and Cracks (less than 6 inches): Can often be repaired by a professional using resin injection techniques.
Long Cracks (more than 12 inches): Usually require windshield replacement.
Cracks in the Driver's Line of Sight: Often require windshield replacement, regardless of size, as a repair may distort your vision.
Cracks that reach the edge of the windshield: Likely require replacement due to structural weakness.

A professional windshield repair typically costs between $50 and $150, while a windshield replacement can range from $200 to $500 or more, depending on the make and model of your car and the type of glass used. Contact your insurance company to see if your policy covers windshield repair or replacement.

Why Professional Help is Crucial

While DIY methods can buy you some time, they are not a substitute for professional repair or replacement. A professional technician has the expertise and equipment to properly assess the damage and perform a safe and effective repair. A properly repaired windshield will restore the structural integrity of your vehicle and ensure your safety on the road.

Ignoring a cracked windshield is not only dangerous but also illegal in many states. Schedule an appointment with a qualified windshield repair technician as soon as possible. The sooner you address the issue, the less likely the crack is to spread, and the more likely you are to save money and avoid a costly replacement.