Immediately after the appearance of cracks on the glass pick up the tape and seal them defect. This will prevent the ingress of dirt. Remember that under the tape it is better to put a piece of clean white paper to prevent penetration of the adhesive into the crack. Such measures will allow to make further repairs more quality and prevent further crack development.
If the dirt still came, then rinse the crack and wipe off any remaining moisture with a vacuum cleaner or water-displacing fluid. Then perform the procedure to prevent the crack growth, this measure approximately 5 mm from where the visible ends of the crack. Drill here, holes that should not affect all layers of laminated glass. Ensure that the drilling was at low speed, to avoid overheating of the glass in this place.
Gently dolomite" the crack up to the hole, making a small click. In the presence of cleavage in the fracture, drill additional holes, which will prevent the divergence of the crack after repair. It is also necessary to act in the case, when the crack reaches the edge of the glass. Remember that such injuries require special attention and care in view of the complexity of quality sizing.
Complete the made holes and the crack with polymer. Pre-apply the special plate, which will prevent contact of the polymer with the environment and prevent leakage. Treat the surface with ultraviolet light to the adhesive composition polymerizable. Remove excess polymer composition, and then thoroughly clean the interior from small fragments, which can bring significant inconveniences in the future. Remember that if cracks quite a lot or they are big sizes, it is better to install the new glass.