How Windshield Repair Works
A windshield is two layers of glass with a plastic layer bonded between them. When a stone hits the outer layer, it can leave a chip or start a crack. Repair does not replace the glass. The installer cleans out the damaged spot, injects a clear resin, and cures it with ultraviolet light. The resin fills the damage, restores much of the glass's strength, and keeps the chip from spreading.
- Repair often takes 30 to 60 minutes.
- The goal is to stop the damage from spreading and improve clarity. It does not make a chip disappear completely.
- Repair works best when done soon, before dirt and moisture get into the chip.
- Not every chip or crack can be repaired safely.
Types of Windshield Damage
| Type | What it looks like | Repairable? |
|---|---|---|
| Bullseye | A round, dark circle with a cone shape | Usually yes |
| Star break | A center point with short cracks radiating out | Usually yes, if the legs are short |
| Combination break | A bullseye with cracks coming from it | Often yes |
| Half-moon (partial bullseye) | A half circle | Usually yes |
| Short crack | A single line, a few inches long | Often yes |
| Long crack | A line running across much of the glass | Usually replace |
| Edge crack | A crack starting at or near the edge | Often replace |
| Stress crack | A crack with no clear impact point, often from heat | Often replace |
When Repair Is Usually Possible
- The chip is roughly the size of a quarter or smaller.
- A crack is short, commonly under about 6 inches. Some installers repair longer ones.
- The damage is in the outer layer of glass only.
- The damage is not at the edge of the windshield.
- There are only one or two points of damage.
- The damage is not directly in the driver's line of sight.
When Replacement Is the Safer Choice
- The crack is long, or growing quickly.
- The damage reaches the edge of the glass.
- The inner layer of glass is damaged.
- There are many chips, or the glass is already pitted.
- The damage is in the driver's direct view and a repair would leave distortion.
- The chip is dirty, wet, or has been left for a long time, and the resin cannot fill it fully.
See the windshield replacement guide for what that involves.
The Repair Process, Step by Step
- Inspect the damage to decide whether it can be repaired.
- Clean the chip. Loose glass and debris are removed, and the area is dried.
- Attach a repair tool that creates a vacuum over the chip to pull out air and moisture.
- Inject the resin so it flows into the break.
- Cure the resin with a UV light until it hardens.
- Scrape and polish the surface so it is level with the glass.
After the Repair
- Follow the installer's instructions on how soon the car can be washed.
- A faint mark where the chip was is normal.
- If the crack starts spreading again, it may need to be replaced.
- Avoid slamming the doors and rough roads for the first day, if you can.
Why Repair Soon Matters on the Gulf Coast
Heat, humidity, and sudden temperature changes put stress on glass. A chip that sits through a few hot days, a cold car air conditioner, and a rainy week can pick up dirt and moisture and grow into a crack. Getting a chip repaired quickly also costs less. See the cost guide for typical prices.
Questions to Ask an Installer
- Can this damage be repaired, or do you recommend replacement?
- How long will the repair take, and can you come to me?
- What is the cost, and will insurance cover it?
- Is there a warranty on the repair, and what does it cover?
- Are you licensed and insured?
Frequently Asked Questions
Can a windshield crack be repaired?
Short cracks, often under about 6 inches, can frequently be repaired. Long cracks, edge cracks, and cracks in the driver's line of sight often need replacement.
How long does windshield chip repair take?
A chip repair commonly takes about 30 to 60 minutes.
Will a repaired chip still be visible?
Usually a faint blemish remains. The repair is mainly to stop the chip from spreading and restore strength, not to make it disappear.
Why do chips turn into cracks?
Temperature changes, vibration, and flexing of the windshield put stress on the damaged spot, so a small chip can spread into a crack, especially in heat.
Is a repaired windshield safe?
A proper repair stabilizes the damage and restores much of the glass's strength, but if the damage is large or in the wrong place, replacement is the safer choice.
How soon should I repair a windshield chip?
As soon as possible. The longer a chip sits, the more likely it is to collect dirt and moisture or spread.
See also: windshield replacement, cost guide, mobile service.