by Bob Beranek
  • facebook

Every repairable break is unique, and some repair professionals say a break or chip is like a snowflake. However, windshield breaks share certain characteristics that allow us to put them in generalized categories. These categories are bullseye, half-moon, star, crack and combination. The National Windshield Repair Association (NWRA) developed a standard for windshield repair called the Repair of Laminated Automotive Glass Standard (ROLAGS) and had it sponsored by the American National Standards Institute (ANSI). It uses the following categories for repairable breaks:

  • Bullseye,
  • Half-moon,
  • Star break,
  • Crack,
    • Short;
    • Long;
    • Edge;
    • Floater;
    • Stress; and
  • Combination break.

The bullseye break is usually the easiest to repair. The outcome is the most pleasing to the customer because it almost completely disappears. However, many techs use the bullseye to demonstrate the repair process because of the ease of repair and pleasing results. This break is usually caused by a dull, slow moving projectile. Dull projectiles cause circular breaks because of the circular “grain” in annealed glass. Only sharp, fast moving projectiles would overcome the circular “grain”, like star breaks or cracks.

A half-moon break is an unfinished bullseye and is caused by an even slower moving dull projectile. Normally half-moons are a little harder to repair because the resin must be forced to the far reaches of the break.

Photo courtesy of

One method of speeding up a half-moon repair is a procedure called refracturing. Some use this method because it makes the break bigger. Since a bullseye repairs so well and the end result is almost invisible, the refracturing technique creates a full bullseye from the half-moon. A tech can use a darning needle or pointed pick and place it directly into the pit of the break. Then they can use a weighted device and tap the needle or pick until the half-moon becomes a bullseye.

This same technique can be used on both the star and the crack repairs as well. You create a bullseye at the base of the pit which makes the repair faster and easier.

Star and crack breaks are caused by sharper and faster moving projectiles. These are typically harder to repair because of the break’s narrow “legs”. It also doesn’t appear as transparent as the bullseye or half-moon. When the break is properly repaired the finished “legs” of the break appear as fine “spider web like” lines when viewed head-on.

The last category of break is the combination break, which is usually caused by a large projectile. The windshield can be hit so hard that the cone of the break is pulverized, causing a star break within a bullseye. The finished repair appears to look like a repaired star break since the bullseye disappears, but the star within the break repairs like a typical star break.

Photo courtesy of

Before any repairs are accepted or completed make sure your customer understands the process and what to expect. Refer to the ROLAGS Standard below:

In my training classes I am asked frequently, “Is drilling a requirement for a good windshield repair?” The answer is no. Drilling is not a requirement.  As a matter of fact, if you can refrain from drilling a pit, the repair will appear better after the process is complete. Not drilling leaves a smaller, less noticeable pit.

You should drill the glass for one reason only. Drilling opens the pit for resin to flow freely.  Sometimes when the break is old, the pit is plugged by debris from the roadway, from car wash wax or other debris forced into the pit by the wipers. This plug hinders the flow of the resin and should be breached or removed to properly complete the repair. Some drill out the plug and others use the edge of a straight edged razor blade to pick out the plug.

I have witnessed techs attempt to drill down to the lamination to fill the break better. Some have said that is what they were taught. Do not do this! The fact is that if you drill all the way down to the lamination, the windshield’s safety has been compromised and it should be replaced not repaired.

The part of the windshield that offers the occupants the greatest barrier for safety is the Polyvinyl Butyral (PVB) interlayer. If it is punctured by hitting it with a drill bit, the PVB is no longer a restriction to ejection. It would fail at the puncture.

The proper procedure is to first use the razor blade edge to pick out the plug. If that fails, then drill the pit only to open it up. Never ever go down to the laminate. Just peck the drill bit into the pit until open and only penetrate less than half of the first layer of glass. Once that is accomplished, the resin will flow nicely. If while you are drilling, and a string of plastic comes up the drill bit, you have gone too far.

Please, DO NOT over-drill.

In my last post, I discussed reasons why pre- and post-scans must be performed on every vehicle coming in for service or repair. I explained ODB-II ports and the scanners used to monitor them. The reasoning behind this directive has been debated. Is vehicle scanning a consumer necessity for safety, or a way to get more money by adding an unnecessary service?

Leading the debate on the side of safety and customer satisfaction are the service providers and carmakers. On the other side, we see the insurance industry and/or the consumer who may not want to pay for this service. The auto glass industry being a service provider in the aftermarket, is caught between a rock and a hard place. On one hand we want to provide a safe and quality auto glass replacement for our customers.  On the other, we want to provide a service that our customers, retail and insurance alike, will value and demand.

Are pre- and post-scans necessary?

Modern vehicles have a plethora of safety and performance features that must perform flawlessly to protect the occupants from harm, and provide long and worry-free service built into them. Some of these features depend on other adjacent or contributing features to work properly and efficiently. Some carmakers feel strongly enough about goals of safety and performance to make pre- and post-scans mandatory for their service providers. We in the auto glass industry, can’t ignore the directives from the vehicle manufacturers or all liability will rest on our shoulders. So, are pre- and post-scans necessary – I say yes. Safety is our goal and the operation of the vehicles’ safety devices after a glass replacement are our responsibility. If it takes scanning the vehicle to assure safety, we have little choice in the matter.

Photo Courtesy of Mitchell International

We need to address this issue sooner rather than later both in our everyday practice of our craft and in our standard that guides us to safe installation.

Are we going to be paid for this added service?

Just as we are fighting for fair payment for recalibration, we may also have to fight for scanning reimbursement. It seems if the car maker requires it, the insurance industry is willing to pay what is necessary for safety. However, they need to be asked in advance of the service.

My advice to all shops:

  • Acquire a vehicle scanner and learn how to use it to scan all vehicles prior to and after an installation.
  • Determine a fair and reasonable price in your market for the service.
  • Create a policy and procedure for when a scan finds issues beyond your ability to repair.
  • Train your technicians on the proper scanning procedures of the tool you choose to purchase.
  • Train your billing agents in proper pre-authorization of scanning costs for retail and insurance customers.

This could be a win-win-win for everyone. It is a win for the customer in added safety and performance, a win for the insurance companies in reduced accident claims, and a win for service providers who have an additional service to offer customers.