How to Sand a Car Mirror Housing to Restore Clarity

Plastic mirror housings pick up haze, shallow scratches, and dull spots from washing, road grit, and careless wiping. If the plastic is painted or clear-coated, the strategy is to level the defects gently and restore clarity with fine wet sanding. The trick is staying in the ultra-fine range so you improve the surface without changing the shape or cutting through coatings.

Why Sanding Matters

Haze and micro-scratches scatter light, making plastic look faded and chalky. A fine grit progression removes the tops of those defects, then refines the scratch pattern so the surface looks clearer and more uniform. Done carefully, you can dramatically improve appearance without replacing the part.

Tools

• Soft sanding pad or foam interface
• Spray bottle with water + a drop of soap
• Microfiber towels
• Masking tape (protect paint edges and adjacent panels)
• Good lighting and a clean working area

Recommended Grit Sequence

• 1200 grit – Start refining visible haze/scratches (light touch)
• 1500 grit – Smooth and unify the surface
• 2000 grit – Final refinement before polishing/protecting

Step-by-Step

1. Wash and dry the mirror housing. Any grit left on the surface can cause new scratches while sanding.
2. Mask edges and nearby paint. Plastic housings often meet painted panels—tape prevents accidental scuffs.
3. Test a small spot first. Choose a corner and see how the plastic responds before doing the whole housing.
4. Wet sand with 1200 grit using a soft pad. Keep it wet, use very light pressure, and sand in short overlapping passes. Wipe often and check progress.
5. Switch to 1500 grit. Increase your working area slightly so you’re blending the refined zone into the surrounding surface.
6. Finish with 2000 grit. Use longer, lighter strokes to leave a very fine, consistent scratch pattern.
7. Clean and inspect under bright light. The surface should look uniformly dull (even scratch) rather than patchy.
8. Protect the finish. If you’re not polishing, apply a plastic-safe sealant/wax to help maintain clarity.

Special Cases

Painted housings: If the housing is painted and cleared, treat it like clearcoat: stay light, keep it wet, and stop immediately if you see color transfer.

Textured plastic: Don’t sand textured areas unless you plan to re-texture/paint—sanding will flatten the texture.

Pro Tips

• Keep pressure low. Plastic heats and distorts more easily than metal.
• Work clean. Rinse the paper and wipe slurry often to avoid random scratches.
• Crosshatch your passes. Light crosshatching helps you see whether you removed the previous grit’s marks evenly.
• Stop early on edges. Coatings are thinnest on sharp edges and corners.

Aftercare

• Rinse and dry fully, especially around seams.
• Apply a protectant (sealant/wax) to help reduce future haze.
• Use microfiber-only cleaning going forward to maintain clarity.

FAQs

• Can I do this dry? Wet sanding is safer on plastics because it reduces heat and clogging.
• Do I need to polish after 2000? Polishing improves gloss, but even without polish, 2000 can noticeably improve clarity on some plastics.
• What if the plastic is deeply gouged? Deep damage may need a coarser step, but that increases risk. For deep gouges, replacement or repainting may be more practical.

Watch & Learn

If you want a simple “restore clarity” kit of grits, this three-step ladder is easy to repeat: 1200 Grit (25 Pack), 1500 Grit (25 Pack), 2000 Grit (25 Pack). Wet sand lightly at 1200, refine at 1500, and finish at 2000 before protecting the surface.

When the scratch pattern is uniform and fine, the housing will look clearer and more even—especially under direct sunlight.