Sanding Drywall Joints: Smooth Walls Without Swirl Marks (120–320 Grit Guide)

Perfectly smooth drywall is the foundation of a flawless paint or wallpaper finish. Poorly sanded joints leave visible seams, swirl marks, or uneven textures that show through once painted. This guide explains how to sand drywall joints correctly, using the right grit sequence and techniques for a professional look.

Why Sanding Drywall Matters

Sanding eliminates ridges, excess compound, and imperfections in the taped joints. Skipping or rushing this step results in lumpy walls that no amount of paint can hide. A careful sanding job ensures your walls look seamless.

Best Tools for Drywall Sanding

• 9x11 in silicon carbide sandpaper sheets (wet or dry use)
• Pole sander or sanding block
• Dust mask or respirator
• Tack cloth or vacuum with brush attachment
• Work light to highlight surface flaws

Recommended Grit Sequence

• 120 grit: Knock down ridges and high spots.
• 180 grit: Blend compound into drywall surface.
• 220 grit: Smooth seams and feather edges.
• 320 grit: Final finish for paint or primer.

Step-by-Step: Sanding Drywall Joints

1. Prepare the area. Remove furniture and cover floors with drop cloths.
2. Start with 120 grit. Use a pole sander to level ridges and dried compound. For controlled work, use 120 Grit (25-pack).
3. Switch to 180 grit. Blend edges where compound meets drywall. This prevents visible lines. Try 180 Grit (50-pack).
4. Refine with 220 grit. Use light strokes to smooth seams and remove swirl marks. Stock up with 220 Grit (100-pack).
5. Finish with 320 grit. Spot-sand under bright light for a flawless surface ready for primer.
6. Clean up. Vacuum dust, then wipe with a tack cloth.
7. Prime and paint. Always seal the surface with primer before topcoating.

Special Cases

For bathrooms or kitchens where moisture is present, always use mold-resistant joint compound and follow up with a high-quality primer before painting.

Pro Tips

• Work under a raking light to spot flaws before painting.
• Use wet sanding (lightly damp sponge with fine grit) in small areas to reduce dust.
• Sand in a circular motion to blend seams more naturally.
• Replace sheets often—clogged sandpaper leaves scratches.

Aftercare

• Store leftover sandpaper flat in a dry place.
• Vacuum walls again before applying primer.
• Dispose of drywall dust safely—avoid sweeping, which spreads dust into the air.

FAQs

• Can I use a power sander? Yes, but be careful—it's easy to sand too deep and damage paper face.
• Do I need to sand between coats of compound? Lightly sand with 180–220 grit between coats for the smoothest results.
• What happens if I skip the final 320 grit? The paint may highlight imperfections under certain lighting angles.

Watch & Learn

For professional results, always stock the full grit range. Explore our Medium Sandpaper Collection and Fine Sandpaper Collection for drywall projects.