What Grit Sandpaper Should Be Used for Car Polishing?
3 Answers
When polishing a car, use 320-grit sandpaper for dark-colored vehicles and 400-grit for newer light-colored cars. Introduction to Car Polishing: Car polishing involves using a polishing machine with a polishing pad and abrasive compound to evenly grind the car's paint surface. It primarily relies on the cutting force of the polishing pad and the fine particles in the abrasive compound to heat and soften the paint, allowing the surrounding paint to fill in scratches. This process results in a smooth and glossy finish that hides imperfections. Precautions for Car Polishing: If your car requires polishing, it is recommended to visit a professional auto detailing shop. Achieving good results without a polishing machine is difficult, and improper operation can damage the car's paint surface.
I often polish the car body myself to deal with scratches or prepare for painting, generally selecting sandpaper grit numbers based on the extent of repair. If you need to remove deep scratches or old paint, use coarse sandpaper around 120 grit—it sands quickly but isn't fine, tends to leave marks, so avoid pressing too hard. Then switch to 240 grit for a smoother surface, which is better for transitional stages. Before painting, you must use sandpaper of 500 grit or higher, preferably 600 grit wet sandpaper, as it provides a high-gloss finish when wet and avoids a grainy paint surface. Different car body parts also require different approaches: for metal parts, start with coarse and then fine sandpaper, while plastic parts like bumpers should begin directly with 180 grit to avoid damage. I always wear gloves and goggles to protect against flying debris—don’t skimp on sandpaper quality, as poor-quality sheets break easily. Electric sanders save effort but require practice to control; beginners should stick to manual sanding for steadiness. The entire process should progress from coarse to fine grit step by step—don’t skip stages to avoid rework. Safety first—always work in a well-ventilated area.
Having worked on cars for several years, I've gained experience in choosing sandpaper for automotive use. For rough tasks like rust removal or leveling surfaces, start with 150-grit sandpaper for high efficiency. Transition with around 280-grit for smoother results. For fine work before painting, begin with 400-grit or higher, wet sanding being preferable. I once made the mistake of using overly coarse 80-grit, which scratched the surface and required re-sanding. It's advisable to test on a small area first. Beginners can start with simple hand sanding blocks—take it slow. Different materials require different grits: medium-coarse for metal body panels, finer grits for plastic parts. Ensure surfaces are completely dry before painting to prevent adhesion issues. Wear a dust mask to avoid inhaling particles, and replace worn sandpaper regularly as it affects results. Keep the workspace dust-free, and progress systematically from coarse to fine grits without rushing. Sandpaper grits range from 80 to 1000—choose based on your specific needs.
