July 14, 2021

Repair of stone-chip and crack damage

Repair of stone-chip and crack damage

According to the US National Windshield Repair Association, many types of stone damage can be successfully repaired. Whether the windshield can be repaired always depends upon four factors: the size, type, depth and location of the damage.

Size and depth

Repair of cracks up to 2.4 inches is within repairable limits; automobile glass with more severe damage needs to be replaced. However, this is dependent on local and state laws. If a crack extends to the edge of the panel then this would compromise the structural integrity of the windshield. Aircraft windshields are designed in such a way that even if a crack were to extend all the way across the panel, the structural integrity is maintained. How many of you actually fly a plane to work or the store to get groceries? Probably not many but I thought it was interesting fact so I decided to include it in this post.


Circular bullseyes, linear cracks, crack chips, dings, pits and star-shaped breaks can be repaired without removing the glass, eliminating the risk of leaking or bonding problems sometimes associated with replacement. This is also a popular way to save money and land fill space.


Some damages are very difficult to repair, or cannot be repaired:

  • on inside of the windshield
  • deep damage on both layers of glass due to a very strong impact
  • damage over rain sensor or internal radio antenna
  • complex multiple cracks
  • very long cracks (i.e. 18–24 inches long)
  • contaminated cracks
  • edge cracks

In cracked windshield repair, air is removed from the damaged area on the windshield with a specified vacuum injection pump. Then using the injection pump, the clear adhesive resin is injected to replace the air in the windshield crack. The resin is then cured with an ultraviolet light. Kind of like the dentist filling a cavity, using an ultraviolet light to cure the filling. When done properly, the damaged area’s strength is restored, as is 90–95% of the clarity.

Call the experts at Nacco of Illinois to repair your windshield today!



Leave A Comment