Sand Hollow-Core Doors Without Veneer Rip-Through

Hollow-core interior doors are lightweight, budget-friendly, and everywhere—but their ultrathin veneer can be unforgiving. Sand too coarse or linger too long at an edge and you’ll cut straight through to paper or core. This guide shows a safe, pro-level process for flattening nibs, scuffing for paint, and blending repairs without risking sand-through. You’ll learn why measured grit jumps matter, how to control pressure and pad hardness, and exactly where to use each abrasive.

Why Sanding Hollow-Core Doors Matters

Factory-finished or previously painted hollow-core doors often have dust nibs, brush marks, and sheen variations. Proper sanding creates a uniform scratch profile so primer or paint bonds reliably and levels out minor texture. The challenge is the thin veneer and soft edges: aggressive grits or hard pads can telegraph through instantly. A careful sequence with light pressure keeps the surface intact while preparing it for a flawless refinish.

Tools You’ll Need

• Random-orbit (RO) sander with dust extraction and a soft interface pad
• Hard sanding block (for isolated high spots and edge control)
• Foam sanding pad/sponges for profiles and bevels
• Wet/dry sandpaper sheets: 180, 220, 320 grits
• Vacuum with brush head, microfiber cloths, tack cloth (non-oily)
• Deglosser or denatured alcohol (finishes-safe) and painter’s tape
• Primer/topcoat per your paint system; raking light for inspection
• PPE: respirator (P100), eye and hearing protection

Recommended Grit Sequence

• 180 grit — Spot-level nibs and minor runs where extra cut is needed.
• 220 grit — Main scuff to degloss uniformly and set adhesion profile.
• 320 grit — Optional refine for ultra-smooth topcoats or darker colors.

Step-by-Step: Safe Sanding for Thin Veneer

1. Prep, remove hardware, and stabilize the door. Pull the door, remove handles/hinges, and set it flat on padded trestles. Mask glass lites and weatherstrip. Wipe the surface with a deglosser or alcohol to remove oils and cleaners that clog paper.
2. Map the surface with light and pencil. Under strong raking light, circle dust nibs, sags, and rough touch-ups. Lightly pencil a crosshatch on each panel—this guide-coat tells you when you’ve sanded evenly without overdoing it.
3. Spot-level at 180 grit (localized only). On drips, touch-ups, or stubborn nibs, level gently with a 180 grit (25-pack) sheet on a hard block. Keep strokes short and flat; stop the moment the defect blends. Avoid broad 180-grit passes on veneer fields.
4. Main scuff with 220 grit. Switch to the RO sander with a soft interface pad and make overlapping, feather-light passes across each panel until the pencil fades uniformly. This sets a tight scratch field for adhesion without burnishing. For consistent control, stock 220 grit (50-pack) for the primary scuff.
5. Edge and profile control. Hand-sand stiles, rails, and beveled edges with the sheet wrapped around a foam pad. Keep the pad slightly off the sharp arris and stroke with the grain to prevent cutting through the veneer edge banding.
6. Optional refine with 320. For high-gloss, deep colors, or doors under harsh lighting, kiss the surface with 320 grit (100-pack). One quick pass reduces swirl visibility and helps topcoats lay down glassy—don’t polish; stop when uniformly matte.
7. Vacuum, tack, and inspect. Remove all dust (panels, edges, and recesses), then tack with a clean, non-oily cloth. Re-check in raking light. Any shiny islands or visible scratches? Re-touch locally at the previous grit instead of re-sanding the entire door.
8. Prime and de-nib. Apply your bonding primer per label. After drying, lightly de-nib with 320 where needed (dust nibs only). Avoid cutting through on panel edges—use a foam pad and the lightest pressure.
9. Topcoat smart. Lay thin, even coats, maintain a wet edge, and follow recoat windows. Most latex enamels benefit from two to three light coats with a gentle 320 de-nib between coats for a furniture-grade look.

Special Cases

Raw or factory-primed replacement slabs: Start at 220 across the field; use 180 only on defects. Many primers sand fast—keep passes brief to preserve veneer thickness.
Heavily brushed/rolled old paint with ridges: Level ridges locally at 180 on a block, then unify with 220. If the old paint chips under tape, consider a more aggressive prep strategy (chemical strip + gentle sand) instead of forcing the veneer.
Panel doors with deep profiles: Switch to foam pads or sponge abrasives; avoid finger-sanding grooves, which creates troughs that telegraph under gloss.
Edge banding and corners: Treat edges as a separate operation—two light hand passes beat one heavy swipe that risks a sand-through.

Pro Tips

• Keep the RO sander flat and let extraction do the work; pressure polishes instead of cutting and invites swirl.
• Re-mark a faint pencil map at each grit change—move up only when the previous marks are fully gone.
• Use a soft interface pad on broad fields for safety, a hard block only where you must flatten.
• Rotate sheets early; dull paper burnishes thin veneer and hides deeper scratches that reappear after paint.
• Always sand with the grain on stiles/rails and align your last RO passes to the panel’s long axis to hide the pattern.

Aftercare

• Allow full cure before rehanging hardware; soft paint around latches scuffs easily.
• Use felt bumpers and gentle cleaners—avoid strong solvents on fresh coatings.
• For future refreshes, a light 320 scuff and careful de-nib is usually enough—save aggressive sanding for localized repairs.

FAQs

• Is 120 grit ever okay on veneer? Only for severe defects, and then locally on a hard block with extreme care. 180/220 is safer for most work.
• Why do edges sand through first? Veneer and paint film are thinnest at arrises. Use foam-pad hand sanding and minimal pressure; keep the RO away from sharp corners.
• Do I need to wet-sand? Not for prep. Keep it dry to protect edges; wet-sanding can swell exposed paper cores on damaged doors.
• Primer peeled with tape—now what? The substrate wasn’t sound. Feather the area at 220, switch to a bonding primer compatible with old coatings, and re-test adhesion before proceeding.
• Gloss shows faint swirls—how to fix? De-nib lightly at 320, clean, and apply one more thin finish coat under controlled lighting.

Video: See the Safe Veneer Workflow

Closing: Treat hollow-core doors as a thin veneer system: local 180 only where needed, disciplined 220 scuff for adhesion, and an optional 320 refine for premium finishes. Control pressure, protect edges, and verify with raking light—you’ll get factory-smooth results without risking a sand-through.