How to Sand Between Coats of Polyurethane on Wood Floors

Polyurethane adds durability and shine to wood floors, but for a flawless finish, sanding between coats is essential. This step ensures each layer bonds properly, eliminates imperfections, and leaves a glass-smooth surface underfoot.

Why Sand Between Polyurethane Coats?

Each coat of polyurethane raises the grain and may trap dust particles. Sanding lightly between coats smooths the surface, removes imperfections, and gives the next coat a strong grip. Skipping this step often results in rough patches or peeling finish.

Tools You’ll Need

• Floor buffer or sanding pole
• 9x11 in sandpaper sheets (wet or dry use)
• Sanding screen (optional for large floors)
• Vacuum and tack cloth
• Protective gear: respirator, goggles

Best Grit Sequence for Polyurethane Floors

• 220 grit: Standard sanding between coats.
• 320 grit: For a finer touch on later coats.
• 400 grit: Optional for ultra-smooth, glossy finishes.

Step-by-Step: Sanding Polyurethane Floors

1. Let coat dry. Allow polyurethane to cure for at least 12–24 hours.
2. Start with 220 grit. Use 220 grit (100-pack) to lightly sand the floor’s surface.
3. Smooth with 320 grit. For later coats, switch to 320 grit (25-pack) for finer sanding.
4. Optional 400 grit. Use 400 grit (50-pack) if aiming for a high-gloss finish.
5. Clean thoroughly. Vacuum and wipe with a tack cloth before re-coating.
6. Apply next coat. Spread polyurethane evenly with a brush or applicator.

Special Cases

For water-based polyurethane, sanding dust may clump—always vacuum thoroughly. For oil-based products, ensure full drying before sanding to avoid gumming.

Pro Tips

• Use very light pressure—just enough to dull the sheen.
• Always sand with the grain, not across it.
• Replace clogged sheets promptly for consistent results.

Aftercare

• Allow final coat to cure for at least 7 days before heavy use.
• Protect floors with felt pads on furniture legs.
• Clean with hardwood-safe products only.

FAQs

• Do I need to sand after the final coat? No—leave the final coat untouched for maximum durability.
• Can I skip sanding between coats? Not recommended—it risks peeling and rough texture.
• Is wet sanding required? Optional—wet sanding with 400 grit gives a smoother, glossier finish.

Watch & Learn

For flawless floors, use eQualle’s 9x11 in sandpaper sheets, available in 25, 50, and 100 packs for wet or dry use. Shop polyurethane sanding sheets here.