Drywall Corner Sanding: Smooth Seams Without Damage (120–220 Grit Guide)

Drywall corners are one of the trickiest parts of finishing a wall. Sand too aggressively and you’ll gouge the joint tape. Skip sanding and your corners will look uneven once painted. With the right sandpaper and careful technique, you can achieve clean, sharp, and smooth drywall corners every time.

Why Sand Drywall Corners?

Corners accumulate excess joint compound during taping and mudding. Sanding removes ridges, blends surfaces, and ensures corners look seamless after painting or texturing.

Best Tools for Corner Sanding

• 9x11 in silicon carbide sandpaper sheets
• Corner sanding sponge or block
• Pole sander for high areas
• Dust mask or respirator
• Vacuum with brush attachment

Recommended Grit Sequence

• 120 grit: Knock down ridges and high spots.
• 180 grit: Blend compound into drywall smoothly.
• 220 grit: Final smoothing before primer and paint.

Step-by-Step: Sanding Drywall Corners

1. Prep the area. Cover floors and wear protective gear to control dust.
2. Start with 120 grit. Lightly sand ridges with a corner sanding sponge. Use 120 Grit (25-pack).
3. Switch to 180 grit. Blend compound into both sides of the corner evenly. Stock up on 180 Grit (50-pack).
4. Refine with 220 grit. Achieve a smooth, paint-ready corner. Try 220 Grit (100-pack).
5. Clean up. Vacuum and wipe with a tack cloth to remove fine dust.
6. Prime. Apply drywall primer to seal before painting.

Special Cases

For inside corners, use a flexible sanding sponge to match the angle. For outside corners with metal bead, sand lightly to avoid cutting through compound.

Pro Tips

• Sand with light pressure—corners are easy to over-sand.
• Work under a bright work light to spot flaws early.
• Use short, controlled strokes instead of long passes.
• Replace sandpaper sheets as soon as they clog with dust.

Aftercare

• Always prime after sanding to prevent uneven paint absorption.
• Store sandpaper flat in a dust-free environment.
• Dispose of drywall dust safely—avoid sweeping to prevent airborne particles.

FAQs

• Can I use power sanders for corners? Not recommended—hand sanding provides more control in tight spaces.
• Do I need to sand between mud coats? Yes, light sanding with 180 grit between coats improves adhesion and smoothness.
• What happens if I skip sanding? Corners may look rough and uneven under paint or light.

Watch & Learn

For flawless drywall finishes, shop our Fine Sandpaper Collection.