Between-Coats Sanding: 220?320 for Silky Finishes

The difference between a good finish and a silky finish is almost always in the between-coats sanding. After each coat of varnish, polyurethane, or lacquer, a quick scuff with 220 ? 320 grit knocks down dust nibs, evens sheen, and gives the next coat something to grip. Done right, this step takes minutes but transforms the final look—smooth to the hand, clear to the eye, and durable under wear.

Why Sand Between Coats

Even in a clean shop, airborne dust lands on wet finishes. Bubbles, brush marks, or raised grain also leave texture. Sanding between coats removes these imperfections and creates microscopic scratches that promote adhesion. Without it, the next coat may not bond well and could peel or feel rough.

Tools & Materials

• 9×11 in silicon carbide wet/dry sheets: 220 and 320 grit
• Soft sanding block or thin foam pad
• Vacuum and tack cloth
• Optional: abrasive pads (gray or maroon) for delicate finishes
• PPE: respirator, gloves, eye protection

Recommended Grit Sequence

• 220 grit — Standard between-coat scuff; levels dust nibs and evens sheen.
• 320 grit — Final refine before the last coat for extra smoothness.

Step-by-Step: Between-Coats Workflow

1. Let finish cure fully. Follow the manufacturer’s recoat window. Sanding too soon gums paper and damages the film.
2. First scuff at 220. Use 220 grit (25-pack) on a soft block. Apply very light pressure in long strokes with the grain. You’re not cutting through—just knocking down nibs.
3. Clean thoroughly. Vacuum the surface and wipe with a tack cloth. Any dust left behind will be sealed into the next coat.
4. Apply the next coat. Brush, spray, or wipe your finish evenly. Let cure fully before repeating the process.
5. Final refine at 320. Before your last coat, give a gentle pass with 320 grit (50-pack). This sets up the smoothest possible surface for a flawless top layer.
6. Topcoat & cure. Apply the final coat, allow to cure per instructions, then buff lightly if needed for sheen.

Special Cases

Waterborne finishes: Raise grain more; plan to sand every coat lightly, not just the first.
Lacquer: Flashes fast—use extra-fine papers and go gently.
Oil finishes: Often require rubbing with 320–400 between coats instead of sanding dry.

Pro Tips

• Always sand with the grain to hide micro-scratches.
• Use a fresh sheet—dull paper polishes instead of cutting.
• Don’t overdo it: a few passes are enough. Sanding through forces a full resand.
• Keep strokes broad; scrubbing motions create uneven sheen.
• Vacuum between every grit to avoid dragging coarser particles forward.

Aftercare

• Allow the final coat to cure fully before heavy use.
• Clean surfaces gently with non-abrasive cloths to preserve sheen.
• Touch-ups: scuff with 320, reapply finish, and feather blend.

FAQs

• Can I skip sanding between coats? Only if the product explicitly says it chemically bonds (some waterborne finishes). Otherwise, always scuff.
• Why not sand with 400 or higher? Too fine can polish instead of cutting, reducing adhesion.
• Do I need to sand the final coat? Not unless you’re polishing for a higher gloss. Leave it as-is or buff gently.
• Is steel wool okay? Not under waterborne finishes—it can rust. Stick to sandpaper or synthetic pads.

Video: Between-Coats Sanding

Closing: Between-coats sanding is a quick insurance policy for professional-looking finishes. With just a few passes at 220 ? 320, you’ll eliminate dust nibs, improve adhesion, and leave surfaces silky to the touch and ready for years of use.