Sand Latex Between Coats: Timing + 220–400 Grit Guide

Latex wall and trim paints dry fast—but they don’t always level perfectly. Tiny dust nibs, roller stipple, and brush marks can stack up across coats. The easiest way to get a professional feel and sheen is a quick between-coat sand. The trick is choosing the right grit, waiting until the paint is truly sandable, and keeping pressure light so you don’t clog paper or wrinkle soft film. This guide gives you a clean, repeatable routine that works on walls, doors, and trim.

Why Sanding Between Coats Matters

Even quality latex can trap lint and flash lap marks as it dries. A disciplined de-nib pass: (1) levels dust and stipple so the next coat lays smoother, (2) tightens the surface microtexture for a more even sheen, and (3) improves adhesion—especially helpful on satin and semi-gloss topcoats. The key is timing: if the film is still soft, it will smear and ball instead of powdering.

Tools You’ll Need

• Hand sanding block (firm face) and a soft foam pad for profiles/trim.
• Random-orbital (DA) sander (optional) at low speed for large, flat doors or panels.
• Sandpaper sheets (silicon carbide or AlOx): 220, 320, 400.
• Vacuum with brush head, microfiber towels, and tack cloth.
• Raking/inspection light; pencil for light guide marks.
• Painter’s tape to protect crisp edges and hardware.
• PPE: dust mask/respirator and eye protection.

Recommended Grit Sequence

• 220 grit: Primary de-nib and light knockdown of roller stipple when the coat is sandable.
• 320 grit: Refinement for trim/doors and higher-sheen topcoats.
• 400 grit: Optional ultra-light touch before final coat to maximize gloss smoothness.

Step-by-Step: Smooth, Even, and Clog-Free

1. Confirm sandability (do the powder test). In a hidden spot, make 3–4 strokes with a small piece of 220. If the paint powders, you’re good. If it smears or pills, wait longer. Humidity and heavy coats extend dry times—patience pays.
2. Protect edges & map the surface. Tape knife-sharp corners and hardware. Under raking light, pencil a faint crosshatch on problem areas (door panels, trim faces). These witness marks help you stop on time.
3. Primary de-nib at 220. Wrap a firm block with 220 Grit (25-pack) and use feather-light, with-grain strokes. On doors/panels, a DA at low speed with a soft interface pad can speed large flats—keep the pad dead-flat. Goal: erase nibs and soften stipple, not cut through.
4. Vacuum and inspect. Dust is abrasive. Vacuum in two directions and wipe with a clean microfiber. Under raking light, you should see a uniform satin without shiny nibs or ridges.
5. Refine at 320 for show surfaces. For trim, cabinets, and doors that you want extra-smooth, take a brief pass with 320 Grit (50-pack). Change your pass direction slightly (then finish with the grain) so any leftover 220 tracks pop and disappear.
6. Optional glass-up at 400 before the final coat. If you’re chasing near-spray smoothness, kiss the surface by hand with 400 Grit (100-pack). Two or three light passes are enough—pressure creates heat and burnish.
7. Clean impeccably. Vacuum again and tack lightly. Any residual dust becomes rogue coarse grit under your brush/roller, creating new nibs.
8. Recoating. Apply thin, even coats. Maintain a wet edge and avoid over-brushing waterborne latex—they set fast. Respect the recoat window on the label.

Special Cases

Fresh paint still soft after hours: Heavy or humid conditions delay cure. Increase airflow and wait for a true powdering response before sanding.
High-build brush marks: Level locally at 220 on a firm block only, then re-enter the 320 refinement step. Don’t try to “grind” them off with a DA into edges—you’ll cut through.
Self-priming paints over glossy surfaces: Scuff the primer coat more thoroughly at 220 to ensure bite before color.
Oil/alkyd trim enamels: They sand differently—often prefer 320–400 light passes once fully hard. Allow extra cure time.

Pro Tips

• Powder = go, smear = no. Always test before committing to the whole surface.
• Block the flats, pad the profiles. Firm block on doors and stiles/rails; thin foam pad for ogees and trim curves.
• Light pressure wins. Dull paper + pressure = heat, clogging, and shiny burnish that can cause flashing.
• Alternate directions. A shallow diagonal at 220, then with-grain at 320, reveals leftover scratches instantly.
• Keep sheets fresh. The moment cut slows or you see “worms” of latex, switch to a fresh section—don’t press harder.

Aftercare

• Let the final coat cure fully before heavy use; doors and trim can feel dry but remain soft for days.
• Clean with non-ammonia, finish-safe products; harsh cleaners can haze young paint.
• Add felt pads on doors/cabinets to avoid early scuffs while the film hardens.
• For touch-ups later, a quick 320 hand de-nib and a thin feathered coat blends best.

FAQs

• Do I have to sand between every coat? For best results on trim/doors, yes—at least a quick 220–320 de-nib. On walls, spot de-nib where needed.
• Wet-sand latex? Not recommended between coats—water can soften the film and smear. Keep it dry until the paint is fully cured (then only for polishing specialty finishes).
• Why does my paper clog instantly? The coat isn’t sandable yet, or you’re using too much pressure. Wait for a powdering response and lighten up.
• Will 400 reduce adhesion? No, used lightly right before the final coat. It simply tightens the scratch field; don’t burnish with heavy pressure.
• Brush vs roller marks? Brush marks respond to block sanding; roller stipple responds to a quick 220 de-nib and thinner next coat. Adjust technique as needed.

Watch & Learn

Closing: A flawless latex finish is mostly about timing and touch. Wait for the coat to powder, then use a tight ladder—220 to de-nib, 320 to refine, and an optional whisper of 400 before the final coat. Keep pressure light, sheets fresh, and your surface impeccably clean. Stock the exact grits so you can stay disciplined at each step—start your de-nib with 220 (25-pack), refine show faces with 320 (50-pack), and reserve 400 (100-pack) for that final glass-up. Do this, and your walls, doors, and trim will look—and feel—like a pro painted them.