A chipped or cracked windshield can present a real safety hazard. Sunlight could hit the crack or chip and become refracted, temporarily blinding you while you are behind the wheel. A damaged windshield is not structurally sound, and you might not be protected against the collapse of your vehicle's cab during a rollover accident.
If you don't have time to immediately contact an auto glass repair shop, there are some things you can do to help stop the crack from spreading and causing additional damage.
1. Glue the crack together.
Cracks in a vehicle's windshield rarely penetrate all of the layers of glass. If you can get the edges of the cracked glass layer to stick together and to stick to the intact layer below, you can buy some time before you need professional repair.
Superglue works great to help prevent a cracked windshield from spreading. Apply the glue at the edges of the crack, taking care not to flood the crack and allow glue to spill out onto the surface of your windshield. Smooth over the glue with an old credit card or piece of stiff plastic.
Once the glue dries, it will hold the edges of the crack together to prevent the damaged layer of glass from additional separation.
2. Fill the crack with clear nail polish.
Acrylic nail polish can also be an effective tool when it comes to preventing a crack in your windshield from spreading. Clear nail polish is transparent when it dries, so it will blend easily into your windshield. This transparency makes the clear nail polish a great option for any cracks or chips that are directly in your line of sight.
Use a soft rag to gently remove any glass residue that might be hanging onto the edges of the crack. Next, brush the nail polish over the cracked area, taking care to flood any gouged sections completely. Smooth out the surface of the nail polish with a credit card or piece of plastic, then wipe away any excess with acetone.
Once the nail polish dries, your crack shouldn't spread until your are able to have it professionally repaired.
3. Avoid sudden temperature changes.
When your windshield gets hot or cold, the glass layers expand and contract. This expansion and contraction could cause any cracks in the surface of the glass to spread. If you need to wait a few days until you can have a crack in your windshield professionally repaired, try to avoid sudden temperature changes in your car.
Park in shady areas if the weather is hot, and avoid blasting your defroster to clear away ice quickly if the weather is cold. Avoiding temperature fluctuations will help to keep your windshield damage at a minimum.