Polishing Acrylic and Plastic Surfaces: Sandpaper Grit Guide

Acrylic sheets, headlights, and plastic parts can become scratched, hazy, or yellowed over time. With the right sandpaper grits and polishing sequence, you can restore clarity and achieve a glass-like finish. This guide covers the full sanding and polishing process for plastics, from rough scratch removal to mirror polish.

Why Sanding Matters for Plastics

Unlike wood or metal, plastic surfaces show every imperfection. Proper sanding gradually levels scratches without overheating or melting the surface. Each grit step is essential for a flawless result.

Tools You’ll Need

• Wet/dry silicon carbide sandpaper
• Soft sanding block or foam pad
• Water spray bottle for lubrication
• Plastic polish or buffing compound
• Microfiber cloths

Recommended Grit Sequence

• 400 grit: Remove deep scratches or oxidation (400 Grit (100-pack)).
• 800 grit: Smooth out 400 grit marks and refine surface (800 Grit (25-pack)).
• 1500 grit: Begin polishing stage (1500 Grit (50-pack)).
• 2000–3000 grit: Final wet sanding for ultra-clear finish.

Step-by-Step: Sanding & Polishing Plastic

1. Clean thoroughly. Wash the surface with mild soap and water. Dry completely.
2. Start with 400 grit. Wet sand scratches evenly, keeping the paper lubricated to prevent heat buildup.
3. Move to 800 grit. Sand in alternating directions to remove the previous grit’s scratches.
4. Refine with 1500 grit. Use light pressure to begin creating a semi-clear finish.
5. Finish with 2000–3000 grit. Wet sand gently until the surface looks uniformly hazy but smooth.
6. Polish. Apply a plastic-safe polish with a microfiber cloth or buffer to restore full clarity and shine.

Special Cases

Headlight restoration often requires UV-sealant application after polishing. For acrylic display cases, avoid harsh compounds that can craze or cloud the material.

Pro Tips

• Always keep sandpaper wet to avoid melting the plastic.
• Work in small sections for consistent results.
• Use microfiber towels only—paper towels can scratch polished surfaces.

Aftercare

• Apply protective coatings or sealants to headlights after polishing.
• Clean with non-abrasive cleaners only.
• Re-polish as needed to maintain clarity.

FAQs

• Can I use automotive polish on plastic? Yes, but ensure it’s labeled safe for acrylic or polycarbonate.
• Do I need power tools? No—hand sanding works fine for small items, but orbital buffers speed up polishing.
• Will sanding remove yellowing? Yes, oxidation layers can be sanded away with proper grit sequence.

Watch & Learn

With patience and the right sandpaper, plastic can look brand new again. Explore our full range of fine and ultra-fine sanding sheets for polishing projects.