How to Repair Scratches on Windshield Caused by Sandpaper?
3 Answers
Clean the glass thoroughly by using a clean cloth to remove dust and debris from the windshield. Wait for the glass to dry completely before starting the scratch repair process. Prepare a clean, lint-free cloth and dampen it with warm water. Wring out the cloth until it no longer drips. Squeeze a pea-sized amount of toothpaste onto the cloth. Be careful with the amount, as it is crucial. You can always add more if needed. Gently rub the scratched area of the glass with the toothpaste-covered cloth using small circular motions for about 30 seconds. Wipe the area again with the cloth. After wiping, the glass should appear shiny. Avoid pressing too hard or rubbing in circles when removing the toothpaste.
Last time my car's windshield got scratched, I tried fixing it myself. If it's just very shallow scratches, you can first try polishing with toothpaste: use a clean cloth dipped in white toothpaste to rub in circles, remember to work in small sections slowly, and finally clean it off with glass cleaner. For deeper scratches, those cheap glass repair kits you find on Taobao for a few dozen yuan are actually quite effective, they come with a small drill bit and resin glue. When operating, remember to strictly follow the instructions to clean off dust first before applying the glue, and make sure to cure it with the UV light for the required time. However, DIY fixes can only handle scratches up to 2-3 mm deep at most. For anything deeper or in the main vision area, I'd advise you to go directly to a professional shop. My neighbor tried fixing a crack himself and ended up with distracting glare on the highway, ultimately having to spend money to replace the windshield.
I once foolishly used sandpaper to remove tree sap and ended up scratching the glass. Light scratches are actually easy to fix: first, thoroughly clean the surface to avoid leaving sand particles that could cause secondary scratches. Purchase a glass polishing compound containing cerium oxide and use it with a drill-mounted polishing wheel, maintaining a consistent speed. Remember to work in sections and avoid rushing, as excessive heat can cause cracks. After polishing, test the results with an oil-based pen—if it glides smoothly, the surface is even. But don't overdo it! Over-polishing can distort the glass, especially with laminated glass where damaging the middle PVB layer renders it useless. A colleague of mine polished his own glass and later complained of halos while driving at night; inspection revealed uneven glass thickness. Nowadays, professional shops use vacuum resin injection equipment to repair deep scratches, restoring up to 90% of the glass's strength, which is much safer.
