How to Sand Metal Surfaces Before Polishing (400, 600, 1000, 1500 Grit Guide)

Polishing metal to a mirror shine starts with proper sanding. Whether it’s aluminum, steel, or brass, each grit level removes imperfections and prepares the surface for high-gloss polishing. This guide explains how to sand metal surfaces step by step using 400, 600, 1000, and 1500 grit sandpaper.

Why Sanding Metal Matters

Raw metal surfaces often contain scratches, oxidation, or machining marks. Sanding eliminates these flaws and creates a uniform surface. Without sanding, polishing compounds cannot produce an even, reflective finish.

Tools You’ll Need

• 400–1500 grit wet/dry sandpaper – for stepwise refinement.
• Sanding block or sponge – for flat or curved surfaces.
• Water spray bottle – reduces heat and prevents clogging.
• Polishing compound & buffing wheel – for mirror finishing.
• Microfiber cloth – for final cleaning.

Best Grit Sequence for Metal Polishing Prep

• 400 grit: Removes light scratches and oxidation.
• 600 grit: Smooths the surface after coarse sanding.
• 1000 grit: Prepares the surface for fine polishing.
• 1500 grit: Creates a satin finish, ready for buffing.

Step-by-Step Metal Sanding

1. Start with 400 grit. Level out scratches and oxidation using 400 grit (100-pack).
2. Smooth with 600 grit. Refine sanding marks using 600 grit (25-pack).
3. Refine with 1000 grit. Wet sand to prepare for polishing using 1000 grit (25-pack).
4. Finish with 1500 grit. Achieve a satin-smooth surface using 1500 grit (50-pack).
5. Polish to gloss. Apply compound with a buffing wheel for a mirror-like finish.

Special Cases

For deep scratches or pitting, start with 220 grit before moving to 400. For stainless steel, sanding direction should follow the grain for best results. Soft metals like aluminum clog sandpaper quickly—always wet sand to extend sheet life.

Pro Tips

• Use light pressure—let the sandpaper do the work.
• Always wet sand fine grits for smooth results.
• Inspect surfaces under bright light to catch imperfections early.
• Work gradually—jumping grits leaves scratches behind.

Aftercare

• Protect polished metal with wax or sealant to prevent oxidation.
• Clean only with non-abrasive cloths to preserve shine.
• Re-polish periodically for long-lasting gloss.

FAQs

• Can I skip straight to 1000 grit? No—400 and 600 grit remove scratches that fine grits cannot.
• Do I need to polish after 1500 grit? Yes—1500 grit leaves a satin finish, polishing creates full gloss.
• Can this process be used on chrome? No—chrome plating should only be polished, not sanded.

Watch & Learn

For mirror-ready results, explore our super fine sandpaper collection.