No, you should not use a side grinder (angle grinder) to polish a car. While it might seem like a powerful tool for the job, the high RPM (revolutions per minute) and aggressive nature of a standard angle grinder pose a significant risk of permanently damaging your car's clear coat and paint. Automotive polishing requires controlled, slow speeds and specialized tools designed specifically for paint correction.
The primary danger lies in the speed. A typical angle grinder operates at 10,000 RPM or higher, generating immense heat from friction. This heat can quickly burn through the clear coat, leaving behind irreversible swirl marks, holograms, or even bare metal. In contrast, a dual-action (DA) polisher or a forced rotation polisher operates at a much safer 2,800 to 6,800 RPM range and uses a random orbiting motion that minimizes heat buildup, making it far more forgiving for beginners and professionals alike.
| Tool | Typical Speed Range (RPM) | Primary Use | Risk Level for Car Polishing |
|---|
| Angle Grinder | 10,000 - 12,000+ | Cutting, grinding, heavy-duty sanding | Extremely High |
| Rotary Polisher | 600 - 3,500 | Professional paint correction, cutting | High (requires expert skill) |
| Dual-Action (DA) Polisher | 2,800 - 6,800 | Safe polishing, waxing, compounding | Low to Moderate |
If you are committed to doing the job correctly, invest in a proper DA polisher. Start with a less aggressive polish and a soft foam pad. The technique is just as important as the tool: work in small sections, keep the polisher moving constantly, and apply minimal pressure to let the machine do the work. The goal is to remove fine scratches and restore gloss, not to strip away layers of your car's finish.
