Recently, there was a thread on the Windshield Repair Forum discussing repairs in the frit band, or as the posted article calls it, the “Danger Zone.” We’ll discuss the purpose of the frit band and the challenges, if any, of doing a repair involving it.
What is the purpose of the frit?
It is a black enamel band that is baked into the internal surface of the glass and accomplishes two things;
- From the inside, it provides a surface that allows the urethane to bond to the glass.
- From the outside, it prevents UV rays from causing damage to the urethane used to hold the windshield in place.
The forum thread discusses two minor difficulties while repairing chips or windshield crack repair in the frit.
Identifying the chips and cracks in that area:
- Damage can be difficult to spot in the black dotted band area due to the black tint and dotted pattern. This makes it a challenge to see the light refract off the damage
Determining if the resin has reached the ends of cracks in that area:
- Injecting clear resin into the frit band will appear black because it optically matches the glass. It can be challenging to identify if the resin has reached the ends of the cracks, or if it is flowing at all.
Challenges Repairing the Frit
These are challenges to be aware of, but certainly not something to be overly concerned about. How do we as technicians handle these challenges? Make sure to inspect the glass, inside and out (including the frit band), closely. Find any existing damage before beginning repairs. If you happen to find damage in the frit band, it’s important to locate the end of the crack. If the end of the crack extends under the urethane molding or to the edge of the glass, make sure to set expectations with your customer and let them know that you can only fill and cure what you can see.
It is possible that resin will not fill all the way to the end of the crack if it’s under the molding. Even if it does, you cannot cure it because the molding blocks the UV. As a general rule of thumb, if you cannot see it, you cannot guarantee it.
For more information on repairing damaged glass in the frit band, give us a call and speak to a certified technician at 541-345-8554.