A crack in your windshield might look small, but it rarely stays that way. The good news is that many cracks can be repaired with resin in under 30 minutes — if you act before the damage spreads. The bad news is that the internet is full of “fixes” that make the problem worse. Here is what actually works, what to avoid, and when a crack has to be replaced instead.
Can a crack be fixed?
A crack under about six inches, outside the driver’s line of sight and not at the edge of the glass, can usually be repaired with resin in under 30 minutes. A chip up to about quarter size can too. Longer cracks, cracks that reach the edge, or damage in the driver’s line of sight mean replacement.
Why glue and superglue don’t work
Household glue and superglue sit on top of the glass instead of filling the break. They are not optically clear, and once they cure inside the crack a professional can no longer inject resin — so a crack that could have been repaired usually has to be replaced.
How to stop a crack from spreading until it’s fixed
- Put clear tape over the damage to keep water and dirt out.
- Avoid blasting hot defrost or cold A/C straight at the glass.
- Don’t slam doors.
- Avoid car washes.
- Get it looked at soon — Michigan freeze-thaw makes cracks run.
Fixing a long crack
A long crack can’t be made safe with resin. The windshield is part of the vehicle’s structure and is replaced — see our windshield replacement page. For the difference between a DIY kit and a professional repair, see our windshield repair kit guide.
What a professional crack repair does
The technician cleans and dries the break, vacuums out the air, injects resin under pressure, UV-cures it, and polishes the surface. The resin fills the crack and bonds it closed, restoring structural integrity and stopping the spread.