Smooth Drywall Patches: 120?220 Grit Before Paint

Even the best joint compound leaves ridges, edges, or fuzz. To make patches disappear under paint, you must sand them properly. The go-to sequence is 120 ? 220 grit. Start coarse to level ridges, then refine smooth so primer and paint roll on without flashing or texture differences.

Why Sanding Drywall Patches Matters

Un-sanded patches show through paint as shiny spots, shadows, or bumps. Coarse sanding alone leaves scratches visible under light. Finer sanding blends the patch seamlessly with surrounding drywall, ensuring a uniform finish once painted.

Tools & Materials

• 9×11 in sandpaper sheets: 120 and 220 grit
• Sanding pole or hand sander with swivel head
• Sanding sponge for corners and detail
• Shop vacuum or drywall vacuum attachment
• Dust mask or respirator
• Tack cloth or microfiber rags

Recommended Grit Sequence

• 120 grit — Knocks down ridges and high spots.
• 220 grit — Refines surface smooth before priming.

Step-by-Step: Sanding Drywall Patches

1. Check the patch. Shine a light across the surface at a low angle to highlight ridges or dips.
2. Level at 120 grit. Using 120 grit (25-pack) on a pole sander, sand lightly to remove ridges. Keep strokes broad and avoid over-sanding into paper face.
3. Feather edges. Blend the edges of the patch into surrounding drywall with long strokes. This prevents visible rings after painting.
4. Refine at 220 grit. Step to 220 grit (50-pack). Sand evenly until the patched area feels indistinguishable from surrounding wall.
5. Vacuum thoroughly. Drywall dust clings—vacuum first, then wipe with microfiber.
6. Prime before painting. Always spot-prime patched areas to equalize porosity and sheen before rolling full coats.

Special Cases

Large patches: Feather wider with 120, then blend entire area with 220.
Inside corners: Use a sanding sponge folded into the corner—avoid cutting paper tape.
Skim coats: Sand only lightly with 220; over-sanding cuts through and exposes fuzz.

Pro Tips

• Use raking light—imperfections jump out at shallow angles.
• Replace sandpaper often—clogged paper scratches instead of smoothing.
• Don’t press hard—let the grit cut. Heavy pressure tears paper face.
• Wear a respirator—drywall dust is fine and persistent.
• Prime patched spots before painting to avoid flashing.

Aftercare

• Inspect after primer—touch up with 220 if needed before final paint.
• Keep leftover compound sealed airtight for future repairs.
• For repaints, scuff walls lightly with 220 for better adhesion.

FAQs

• Can I just paint over compound? No—unsanded patches show through paint and peel easier.
• Why 120 first? It cuts ridges fast. Starting finer wastes time and loads paper.
• Why stop at 220? Finer grits polish compound slick, reducing primer bond.
• Is wet sanding an option? Yes—wet sponges reduce dust but are slower and risk softening paper tape.

Video: Drywall Patch Sanding Demo

Closing: For invisible drywall repairs, sand smart: 120 to knock down, 220 to refine. Prime before paint, and your patches will disappear seamlessly into the wall.