What grit sandpaper do I use between coats of a waterborne enamel on kitchen cabinet doors, and what am I actually trying to accomplish with that sanding?

Grit: 320-grit (sanding sponge or screen) is the standard sweet spot. Use 220-grit only if the previous coat has significant texture/dust nibs; follow with 320. Never go coarser than 220.

What you are actually accomplishing:

1. Mechanical Adhesion (The "Tooth"): Waterborne enamels cure via coalescence. Unlike solvent lacquers, they do not chemically "melt" into the previous coat (no solvent bite). You must abrade the surface to create microscopic scratches for the next coat to lock into. No sand = delamination risk.
2. Defect Removal: Leveling orange peel, dust nibs, and brush/roller stipple.
3. Gloss Uniformity: Dulling the previous sheen so the fresh coat wets out evenly without crawling or "fish-eyes."

Critical Process Details:

• Timing: Sand only when fully cured to touch (typically 2–4 hrs @ 70°F/50% RH). If it gums the paper, wait longer. Do not exceed the manufacturer’s recoat window (often 24 hrs) without sanding; beyond that, adhesion drops sharply.
• Technique: Light pressure. One pass with a foam sanding sponge (conforms to profiles) or 320-grit Abranet screen. You are scuffing, not stripping. The surface should look uniformly dull, not scratched through.
• Cleanup: Vacuum + tack cloth (water-dampened microfiber for waterborne; solvent tack rags can leave residue). Zero dust before next coat.

Pro Tip: If using a fine-finish sprayer (HVLP/Airless fine finish tip), you can often skip sanding only if recoating within the "chemical window" (usually 1–2 hrs) and the film is perfectly smooth. For brush/roll: always sand.

For sanding between coats of waterborne enamel on kitchen cabinet doors, use 220-grit sandpaper.

What you’re accomplishing:

• Removing dust nibs and minor imperfections: Waterborne enamels dry to a hard, smooth film that can trap airborne dust or develop slight texture (orange peel, brush marks) as it cures. Light sanding flattens these without cutting through the coat.
• Promoting adhesion: While waterborne enamels bond well to themselves, a very light scuff-sand creates microscopic “tooth” for the next coat to grip, reducing the risk of delamination — especially important on high-touch surfaces like cabinet doors.
• Ensuring a flawless final finish: Each sanding pass builds a uniformly smooth substrate, so the final coat levels out to a professional, factory-like sheen.

How to do it:

• Wait until the coat is fully dry (follow manufacturer’s recoat time — typically 2–4 hours for waterborne enamel, but check the label).
• Sand lightly with 220-grit paper wrapped around a sanding block or use a fine foam sanding pad. Do not sand aggressively — you’re not removing material, just smoothing the surface.
• Remove all dust with a tack cloth or vacuum + lint-free cloth before applying the next coat. Any residual dust will show in the next layer.

Avoid:

• Grits finer than 320 (ineffective for tooth) or coarser than 180 (risks cutting through thin coats or leaving visible scratches).
• Sanding through to primer or bare wood — if you see color change, you’ve gone too far.

This step is critical for a durable, high-end finish on cabinets. Skip it, and you risk a rough, uneven, or peeling surface over time. (Reference: ASTM D4236 for coating compatibility; manufacturer tech sheets from Benjamin Moore Advance, Sherwin-Williams ProClassic, or General Finishes High Performance typically recommend 220-grit intercoat sanding.)