Once there is a break in the glass of this fashion the likelihood is that it will increase in size, particularly if it is near the edge of the glass, and/or is exposed to temperature variations or extremes. If this occurs, depending on the size of and position on the windscreen, and the number of cracks that extend, it may pass beyond the point of repair. Additionally, over an extended period of time dust and contaminating material can enter the break slowly reducing the extreme optical improvement that is possible to achieve with a freshly cracked screen.
What you are seeing is actually the "air gap" that now exists internally in the outer layer of your laminated windscreen in these various types of breaks due to the altered light refraction. Filling that "air-gap" with the aid of a pressure/vaccuum injection system and a resin that is optically matched (and meets Australian Standard AS/NZS2366:1999) to the glass, displaces the air thus reducing the reflective appearance dramatically and can be virtually undetectable.
The resin also possesses strong bonding properties and "glues" the cracks, thereby preventing further cracking. With some types of crack or chip windscreen repairs a tiny hole may be drilled, just penetrating the outer surface of the glass to create a passageway through which the resin can be injected.
This procedure is more often required at the "live" end of a spreading crack to stop-drill the elongation thereby halting its progress across the windscreen.
This hole is obviously then filled with the optically clear resin to smooth and seal the windscreen surface. Windscreen chip and crack repair is actually a relatively quick process.
An average windscreen chip or crack repair, once we are on-site, takes less than 20 minutes. All our repairs come with a life-time warranty not to crack and are also guaranteed for registration inspections.
Windscreen Repairs Australia - Phone (02) 9638 1738