The Car Windscreen is an engineering marvel designed for both style and substance. Over the lifetime of an Car, Truck or SUV, the all-important Windscreen Glass is engineered to take a beating from structural support and handling design stresses while driving, to providing UV protection and safety performance for vehicle occupants in the event of a mishap.
The Windscreen isn’t invulnerable however; there are a host of roadside hazards that can nip, chip or even crack the modern day Windscreen.
This article takes a closer look at how Windscreen repair technicians approach such damage, when considering the option of repairing a Windscreen, rather than replacing it.
The Windscreen, for your information, is made up of laminated Automotive Glass. This is actually two layers of glass, sandwiched around a thin barrier, that when safely heated becomes Automotive Safety Glass. The barrier in between the Glass, called the lamination helps to hold broken pieces of Glass together in the event of a mishap.
Windscreen repair is the process of injecting a curable resin into the outer layer of Glass on a chipped Windscreen to restore that layer of Glass, and while that may sound relatively simple, there are a number of factors to consider when identifying and executing a successful repair.
Let’s start by looking at what a repair technician looks for when assessing what can reasonably be repaired. Traditionally, breaks in a Windscreen have fallen under the following eight descriptors;
Bullseye, Half Moon, Star and Combination. A Bullseye is a clean separated cone shaped break in the outer layer of Glass that slightly resembles a Bullseye on a dartboard. Similar to the Bullseye, The Half Moon is distinguished by its half-moon semi-circle around the impact point, and is also a cone shaped break. A Star break is marked by several distinct fractures and rays that radiate outwards from the impact point like legs. A Combination break is any break that combines two or more of the break types, but an experienced technician will have seen many more types of breaks.
To those original four, we can add Starburst, Angel-wing, Straight-line break and Crack. A Starburst is similar to a Star break, with a larger number of rays radiating outward from the impact point. The Angel-wing is a distinct Combination break, whose rays extend primarily left and right of the impact point like wings. Straight-line breaks are longer breaks, with a distinct left to right fracture, splitting across the impact point. A Crack is a break resembling a line within the outer layer of Glass, running from the surface of the outer layer of glass to the lamination. Cracks can curve or have sharp twists and bends.
Each of these break types is generally repairable, depending upon its size, depth and location on the Windscreen.
Special care must be taken for example, when making a repair near the edge of the Windscreen, where design stresses are higher. You must be able to fully access or see the break in order to repair it. The days of using a dime, a quarter and a dollar to determine what can reasonably be repaired are rapidly becoming a thing of the past. New technologies and new systems are available, which give the repair technician an opportunity to predict the probability of a successful repair, based on an analysis of the type of break and the elements that make up the break.
Generally speaking, the larger and more complex the break, the more you must rely on the skill of the technician to make repairs.
Repairs are made, or not made, on a case by case basis based on the technicians understanding of breaks, skill with repair equipment and expectation for a high quality repair.
In general, most common breaks are repairable, regardless of the location on the Windscreen, provided the repair equipment can be centred over the break. The important exception to this, is a break located within the driver’s critical sight area. This critical sight area or acute area is based on the driver’s line of sight over the steering wheel. Any break in this area, even a properly repaired break, may be distracting. Meaning, it is quite possible that the only safe and proper solution will be to replace the Windscreen. Consideration must be made for the height differences of all potential drivers of the vehicle, when reviewing breaks in the acute area. This rule is governed by your states RMS Safety Rules. NSW RMS Vehicle Standards Information
Properly trained technicians assess the damage, prepares the chip or break for repair. Executes the repair, using a qualified repair system, and allows the repair to cure, using a portable UV lamp or the natural UV rays found in sunlight. Cleaned and polished, the repair is shown to the customer.
By now, you must be wondering, “what do all these break types and break elements mean to me ?” In truth, it’s all about being able to look at a break and determine based on size, type and location, whether or not you can choose repair as a viable alternative to a Windscreen replacement. Always have the break inspected by a qualified repair technician, as you may have seen Windscreen breaks are generally very small. What you’ve read today has given you a very detailed description on the many facets of the breaks you may encounter. The more complicated the break, the more you need to rely on technology, training and technique of a skilled repair technician. This knowledge is your key to approaching Windscreen repairs like a pro.