Windscreen Chip Repairs

Here are the key questions we ask when assessing the repair potential of a chip in a windscreen, using a systematic approach to ensure safety, effectiveness, and compliance with local regulations (which are generally consistent across Australia for these types of repairs).

These questions cover the “3 Ps”: Position, Primary Damage, and Peripheral Factors.

1. Position / Location of the Chip:

This is often the most critical factor for safety and legality.

• Is the chip in the Critical Vision Area (CVA) / “A-zone”?
  • Clarification: This is generally defined as the area directly in the driver’s line of sight, typically an area about 290mm wide, centered on the steering wheel, and extending from the bottom to the top of the wiper sweep.
  • Why it matters: In Australia, chips in the CVA are subject to stricter rules. Generally, only a single chip up to 10mm in diameter is permitted in the CVA. Multiple chips or larger chips usually require windscreen replacement.
• How far is the chip from the edge of the windscreen?
  • Clarification: Measure from the very edge of the glass (not the trim) to the nearest point of the chip.
  • Why it matters: Chips within 5-7 cm (approx. 2-3 inches) of the edge are generally not repairable. This area is under significant stress from the vehicle’s frame, and a repair can compromise structural integrity or lead to further cracking.
• Is the chip in the path of a wiper blade?
  • Why it matters: Repeated wiper movement over a repaired chip can cause wear to the wiper blade and potentially degrade the repair over time, affecting clarity.

2. Primary Damage Characteristics (Type & Size):

This determines if a Windscreen Resin Repair Kit can effectively fill and bond the damage.

• What type of chip is it?
  • Clarification:
    • Bullseye: Circular impact with a cone-shaped break. Generally good for repair.
    • Star Break: Central impact with cracks radiating outwards like a star. Repairable if cracks aren’t too long.
    • Combination Break: A mix of bullseye and star break. Common and often repairable.
    • Half Moon/Crescent: Partial bullseye.
    • Pits/Surface Chips: Very small surface damage, sometimes just a divot. These are often too small to hold resin effectively or don’t reach the inner layer.
    • Cracks: Is it a long crack extending from a chip? Generally, cracks longer than a 5-cent coin (approx. 2cm) or multiple radiating cracks exceeding 5cm are not suitable for chip repair kits and indicate a need for replacement.
  • Why it matters: Different chip types affect resin penetration and the visual outcome. Some (like long cracks) are simply beyond the scope of a chip repair kit.
• What is the overall diameter of the damaged area (including all radiating cracks)?
  • Clarification: As discussed, generally up to a 20-cent coin (approx. 28.5mm), possibly up to a 50-cent coin (approx. 31.5mm) for simpler bullseyes, is the maximum for effective repair with standard kits like Esprit Elite Pro.
  • Why it matters: Larger chips make it difficult for resin to fully penetrate, cure evenly, and maintain structural integrity.
• Is the chip just on the outer layer of glass?
  • Clarification: Most chips are to the outer layer, but extremely deep impacts can affect the inner layer or the PVB (Polyvinyl Butyral) interlayer.
  • Why it matters: If the damage goes through both layers of glass or significantly impacts the PVB interlayer, it’s generally not repairable and requires replacement.
• Are there multiple chips close together?
  • Why it matters: Even if individually repairable, multiple chips in close proximity can create a weakened area.

3. Peripheral Factors (Age, Contamination, and Pre-existing Conditions):

These can significantly impact the success and clarity of the repair.

• How old is the chip?
  • Why it matters: Newer chips (within a few days/weeks) are generally easier to repair as they have less time to accumulate dirt and moisture.
• Is there any visible contamination (dirt, moisture, car wash soap, previous attempts at repair)?
  • Why it matters: Contamination prevents the resin from bonding properly to the glass, leading to a poor, cloudy, or failed repair. While cleaning is part of the process, heavily contaminated chips are difficult or impossible to salvage.
• Has anyone attempted to repair it previously (e.g., with super glue or DIY kits)?
  • Why it matters: Super glue, in particular, will make a professional repair impossible as it permanently blocks the cracks and prevents proper resin penetration.
• Is there any other existing damage on the windscreen (e.g., other chips, long cracks, delamination)?
  • Why it matters: The overall condition of the windscreen needs to be considered. Multiple points of damage might indicate a need for replacement rather than continued repairs.
• Is the windscreen heated (e.g., for defrosting)?
  • Why it matters: Heating elements can be damaged during drilling if not careful, and temperature changes can affect the repair process and curing.
• Is the chip affecting the function of ADAS (Advanced Driver-Assistance Systems) cameras or sensors?
  • Why it matters: Many modern vehicles have cameras and sensors mounted behind the windscreen. Even a successful repair might still cause optical distortion that interferes with ADAS calibration and functionality, potentially requiring a specific recalibration or even replacement.

By systematically asking these questions, a technician can make an informed decision about the repair potential of a windscreen, ensuring a safe, effective, and compliant outcome for the customer.