Last Updated on January 22, 2025 by Nate Schnell
A cracked windshield is more than an inconvenience; it’s a safety hazard. Even small cracks can impair visibility and worsen over time, especially under the stress of driving or weather changes. Thankfully, minor cracks can be repaired at home with the right tools and a bit of patience. Here’s a detailed guide to help you fix a cracked windshield.
Is Your Windshield Crack Fixable?
Before attempting any repairs, it’s important to assess whether the crack is repairable:
- Crack Location: Cracks on the edges of the windshield compromise its structural integrity and typically require replacement. Look for cracks within the dark border of the windshield to determine edge damage.
- Crack Depth: Windshields are made of two layers of glass with a laminate layer in between. If the crack only affects the outer layer, it can usually be repaired. If the inner layer is damaged, replacement is necessary.
- Crack Size: As a general rule, if the crack is smaller than a quarter or a chip less than 1 inch in diameter, it’s likely repairable. Larger cracks may require professional attention or full replacement.
Tools and Materials You’ll Need
To fix a cracked windshield, you’ll need a windshield repair kit, which includes:
- Resin
- Applicator disk
- Pedestal
- Syringe
- Alcohol wipes
- Curing strips
- Razor blade
You can find these kits at most hardware stores or online.
Step-by-Step Windshield Crack Repair
1. Prepare Your Car and the Windshield
- Move the Car to the Shade: Direct sunlight can cure the resin prematurely, so park in a shaded area.
- Warm the Windshield: If the weather is cold, gently warm the windshield to ensure the resin flows properly.
- Clean the Area: Use alcohol wipes to clean around the crack, removing dirt and debris for better resin adhesion.
2. Pre-Treat the Crack
- Use the safety pin provided in the kit to carefully remove any loose glass fragments from the crack.
- Place a piece of cardboard inside the car behind the crack to make it more visible during the repair process.
3. Attach the Repair Disk and Pedestal
- Remove the adhesive backing from the disk and stick it directly over the crack with the hole centered.
- Secure the pedestal to the disk, ensuring the tube aligns perfectly with the crack.
4. Apply the Resin
- Fill the pedestal’s reservoir with resin from the kit. Be cautious not to overfill, as the resin can spill.
- Insert the syringe into the pedestal and lock it into place.
5. Create a Vacuum
- Pull the plunger of the syringe upwards and lock it with the pin provided. This creates a vacuum that removes air from the crack.
- Let the syringe sit for about 10 minutes. Check the crack from inside the car to ensure air bubbles are disappearing.
6. Fill the Crack
- Release the vacuum by removing the syringe, then reinsert it and push the plunger down to force resin into the crack.
- Lock the plunger in place and let it sit for about 20 minutes to allow the resin to penetrate fully.
7. Cure the Resin
- Carefully remove the syringe and the disk using the razor blade.
- Place a small drop of resin over the crack and cover it with a curing strip.
- Leave the strip to sit for an hour in sunlight or use a UV lamp to cure the resin.
8. Final Cleanup
- Remove the curing strip with the razor blade.
- Scrape off any excess resin using the blade, being careful not to scratch the glass.
- Clean the area with alcohol wipes to remove residue.
When to Replace Your Windshield
While small cracks can often be repaired, some situations call for windshield replacement:
- The crack is larger than a quarter or longer than 6 inches.
- The crack has penetrated both layers of glass.
- The crack is on the edges of the windshield.
- Multiple cracks compromise the windshield’s integrity.
Preventing Windshield Cracks from Spreading
To stop a crack from spreading:
- Repair it promptly with a windshield repair kit.
- Avoid sudden temperature changes, such as pouring hot water on a cold windshield.
- Drive cautiously over rough roads to minimize stress on the glass.
Can You Repair a Windshield Crack Yourself?
Yes, minor cracks and chips can be repaired at home using a windshield repair kit. The process is straightforward and typically takes about an hour. However, if the crack is extensive or located in a critical area (such as directly in the driver’s line of sight), professional assistance is recommended.
By following these steps, you can restore your windshield, prevent further damage, and save money on costly replacements. For severe cracks, consult a professional to ensure your safety on the road.
