How to Sand Wood Trim for Painting (100, 150, 180, 220 Grit Guide)

Wood trim frames windows, doors, and baseboards—making it one of the most visible features in any room. For a flawless paint or stain finish, sanding is essential. The right grit sequence smooths out imperfections, removes old coatings, and prepares the trim for durable results. This guide explains how to sand wood trim step by step using 100, 150, 180, and 220 grit sandpaper.

Why Sanding Trim Matters

Trim often collects dings, dents, and paint buildup over time. Sanding removes roughness and ensures that primers and paints bond evenly. Without sanding, imperfections remain visible, and paint may chip or peel prematurely.

Tools You’ll Need

• 100–220 grit sandpaper – fine to medium for progressive smoothing.
• Sanding sponge or block – perfect for detailed profiles and edges.
• Orbital sander – useful for flat trim surfaces.
• Vacuum & tack cloth – removes dust before finishing.
• Primer & paint – for sealing and finishing after sanding.

Best Grit Sequence for Trim Sanding

• 100 grit: Removes old finish, paint, and surface imperfections.
• 150 grit: Smooths surfaces after coarse sanding.
• 180 grit: Prepares wood for primer or stain.
• 220 grit: Final smoothing for a paint-ready surface.

Step-by-Step Trim Sanding

1. Start with 100 grit. Strip paint buildup or varnish using 100 grit (50-pack).
2. Smooth with 150 grit. Even out surfaces using 150 grit (25-pack).
3. Refine with 180 grit. Prepare trim for primer with 180 grit (25-pack).
4. Finish with 220 grit. Lightly sand for a smooth paint-ready surface using 220 grit (100-pack).
5. Clean thoroughly. Wipe with tack cloth before painting.

Special Cases

For detailed trim with grooves and profiles, use sanding sponges to reach curved edges. On pre-primed trim, skip coarse grits and start at 150 grit. Veneered trim requires caution—never sand below 150 grit to avoid damaging the surface.

Pro Tips

• Sand with the wood grain for smooth results.
• Remove trim from walls when possible for easier sanding.
• Seal trim immediately after sanding to avoid dust contamination.
• Replace sheets often—trim details wear sandpaper quickly.

Aftercare

• Inspect painted trim annually and touch up scratches.
• Clean with gentle cleaners to preserve finish.
• Re-sand lightly before repainting for best adhesion.

FAQs

• Do I need to sand if my trim is pre-primed? Yes, lightly with 180–220 grit for adhesion.
• What grit should I stop at for stain? 180 grit works best for stain absorption.
• Can I sand painted trim without stripping first? Yes, just scuff with 100–150 grit to remove gloss.

Watch & Learn

For flawless trim refinishing, explore our medium and fine sandpaper collection.