Sanding Between Coats of Polyurethane for a Perfect Finish (220–400 Grit Guide)

Applying polyurethane can transform wood surfaces into durable, glossy finishes—but only if you sand between coats. Without sanding, dust nibs, bubbles, or brush marks may remain visible. Using eQualle 9x11 inch wet/dry sandpaper sheets in the right grit sequence ensures each layer bonds smoothly, resulting in a flawless finish.

Why Sand Between Polyurethane Coats?

Each coat of polyurethane leaves behind small imperfections. Sanding smooths these out while creating a micro-textured surface that helps the next coat adhere properly. This is the secret to a professional, glass-like finish on furniture, floors, or countertops.

Tools You’ll Need

• Foam sanding block or orbital sander
• Tack cloth or vacuum
• Microfiber cloth
• eQualle 9x11 in Wet/Dry Sandpaper Sheets

Best Sandpaper Grits for Polyurethane

• 220 Grit (100-pack) — Standard grit for sanding between the first and second coat.
• 320 Grit (25-pack) — Refines the finish and removes minor imperfections.
• 400 Grit (50-pack) — Final sanding grit before the last coat for silky smoothness.

Step-by-Step: Sanding Between Polyurethane Coats

1. Apply the first coat. Brush or wipe polyurethane onto a clean, dust-free surface. Let dry fully according to product directions.
2. Sand with 220 grit. Once dry, lightly sand the surface with 220 grit sheets to remove raised grain and imperfections.
3. Wipe clean. Use a tack cloth or vacuum to remove sanding dust.
4. Apply the second coat. Brush evenly and let it cure fully.
5. Sand with 320 grit. Smooth out brush marks or dust particles before the next coat.
6. Repeat as needed. For additional coats, continue sanding lightly with 320 grit.
7. Finish with 400 grit. Before applying the final coat, use 400 grit sheets for an ultra-smooth base.
8. Apply the final coat. Let it cure undisturbed for a professional finish.

Special Cases

For satin polyurethane, sanding up to 320 grit is usually sufficient. For high-gloss finishes, sanding with 400 grit before the last coat ensures maximum clarity and shine.

Pro Tips

• Never sand too aggressively—light pressure is enough to scuff the surface.
• Always sand with the grain to avoid swirl marks.
• Allow full curing time between coats to prevent gumminess.

Aftercare

• Let the final coat cure for at least 24–48 hours before light use.
• Avoid placing heavy items on the surface for at least a week.
• Clean with a damp cloth—avoid harsh cleaners that damage polyurethane.

FAQs

• Can I skip sanding between coats? Not recommended. Skipping can lead to adhesion issues and visible imperfections.
• Is wet sanding necessary? Wet sanding with 400 grit can give a smoother finish but isn’t required for most projects.
• How many coats are ideal? Most projects need 2–3 coats for durability and shine.

Watch & Learn

For flawless finishes, rely on eQualle Sandpaper Sheets (9x11 in, Wet or Dry). Browse the full fine grit collection to keep your woodworking projects looking professional.