How to Repair Splinters and Cracks in the Windshield

Before you know it, that little splinter on your windshield can expand and form a wide crack. The key to treating a crack in a windshield is to repair it quickly, otherwise a full replacement may be necessary. Several companies produce windshield splinter repair kits that include a syringe, adhesive and crack fillers. If this method seems too daunting, a simple home remedy may be enough to stop a splinter from spreading and avoid the need for an immediate trip to the machine shop.


  1. Move your car to a shady area. The sun can dry the chip adhesive too fast.
  2. Thoroughly dry windshield with clean, soft towels. When water enters a crack, it moves quickly and acts as an abrasive. This moisture can spread the cracks and needs to be removed before repairing.
  3. Apply one of the adhesive strips of the kit centered on the splinter of the windshield. Attach the apparatus on this strip with the cylinder pointing upwards.
  4. Remove the cap from the included syringe and insert the tip into the opening of the device. It is filled with the adhesive used to fill the splinter. Pull the syringe handle upwards and leave it at its maximum for one minute. This removes any bubbles from the crack and prepares the adhesive to be injected.
  5. Release the syringe handle, allowing the adhesive to be pushed into the crack. Repeat this process until a suitable amount of adhesive has been inserted.
  6. Remove the syringe, the apparatus and the adhesive strip from the windshield. A small protuberance should be visible above the crack. Let it dry for an hour before removing it with a razor blade. Use a wet towel with alcohol to remove any remaining adhesive from the crack.

Nail polish

  1. Move your car to a shaded area to avoid premature drying.
  2. Apply a layer of clear nail polish to the outside and the inside of the windshield using a nail polish applicator. Brush along any crack that needs repair. The nail polish serves as a temporary adhesive that fills the cracks and prevents them from expanding.
  3. Move the car to the sun to dry and clean any blasted enamel with a clean towel.

Tips & Warnings

  • Nail polish is a temporary solution. Eventually, a stronger repair or a full replacement may be needed.
  • Follow the instructions in your repair kit. Each product may have different subtleties that might require a different action plan.