How to Sand Drywall Patches for Seamless Repairs (120–400 Grit)

Drywall patches can look obvious if not sanded properly. Whether repairing holes, dents, or cracks, the sanding process determines whether the patch blends seamlessly with the surrounding wall. This guide explains grit progression, techniques, and tips for flawless drywall repairs.

Why Sand Drywall Patches?

Joint compound used in patches dries unevenly, often leaving ridges or bumps. Sanding levels these areas, feathers edges, and creates a uniform surface that disappears under paint.

Tools You’ll Need

• Drywall sanding sponge or block
• Dust mask and safety glasses
• Vacuum and tack cloth
• Wet/dry sandpaper sheets (120–400 grit)

Recommended Grit Sequence

• 120 grit: Leveling dried compound and ridges.
• 180 grit: Smoothing and feathering edges.
• 220 grit: General blending before primer.
• 320–400 grit: Final finish for high-visibility areas.

Step-by-Step Process

1. Inspect the patch. Check for raised edges or uneven compound.
2. Start with 120 grit. Use 120 grit (25-pack) to knock down ridges.
3. Feather edges with 180 grit. Smooth transitions with 180 grit (50-pack) sheets for blending.
4. Blend with 220 grit. Sand across the patch using 220 grit (100-pack) for even texture.
5. Finish with 320–400 grit. Use 400 grit (10-pack) for a silky surface before painting.
6. Clean thoroughly. Vacuum dust and wipe with a tack cloth.
7. Prime and paint. Apply drywall primer before topcoats for consistent coverage.

Special Cases

For large patches, sand in wide circular motions to avoid creating depressions. For ceiling patches, use a sanding pole with dust collection to reduce mess.

Pro Tips

• Always sand lightly—too much pressure can dig into the patch.
• Hold a work light at an angle to reveal imperfections.
• Wet sanding with fine grits reduces dust and creates smoother finishes.
• Don’t skip primer—paint alone won’t hide patch differences.

Aftercare

• Check patched areas after priming—re-sand if imperfections appear.
• Apply at least two coats of paint for full coverage.
• Store leftover sandpaper in a dry bag for future repairs.

FAQs

• Can I skip sanding small patches? No—even small patches need sanding to blend properly.
• Do I need to sand between coats of compound? Yes—light sanding ensures smooth layering.
• What grit is best before painting patches? 220 grit provides a consistent surface for primer and paint.

Watch & Learn

Sanding drywall patches is the difference between a visible repair and a flawless wall. Stock up on medium grits, fine sheets, and super fine sandpapers to achieve invisible drywall repairs.