How to Repair a Cracked Plastic Shell Below the Car Headlight?
2 Answers
Single-component silicone glass adhesive is a paste-like material that solidifies into a tough rubber-like solid upon contact with moisture in the air. Epoxy adhesives are mainly composed of epoxy resin and a curing agent. To enhance certain properties and meet different applications, auxiliary materials such as toughening agents can also be added.
The plastic housing of the headlights on my old car also cracked last year when I scraped against a wall corner while parking. The crack extended from the edge to the center. I immediately took photos for documentation and asked for advice in a WeChat group of car enthusiasts. Some suggested using epoxy glue for a DIY fix, but I was concerned about reliability, so I drove to my regular repair shop. The mechanic inspected it and said the crack wasn’t too deep, recommending plastic welding: first softening the plastic with a heat gun, applying professional adhesive to press it together, then sanding and polishing. The whole process cost 260 yuan and took about an hour. It’s been over a year now with no issues. He also reminded me that such plastic housings are prone to aging and cracking, and regular cleaning can extend their lifespan. If the crack exceeds 2cm, a replacement is necessary. In short, don’t delay repairs—water seepage could damage the headlight circuitry and affect nighttime driving. DIY repairs are possible, but you must use the right tools and materials, such as high-temperature-resistant adhesive.