Feather-Edge Car Paint Chips: 80–320 Grit to Primer-Ready

Chipped paint looks small, but the fix lives bigger than the chip. If you simply dab touch-up over a sharp crater, the edge telegraphs forever. The solution is feather edging: shaping a smooth taper from bare metal (or plastic) through primer and color to the surrounding clear so your repair disappears after primer and paint. This guide walks you through a clean, repeatable process with a tight grit ladder—80 → 180 → 320—so you land on a uniform, primer-ready surface without gouges or halos.

Why Sanding (Feathering) Matters

A chip exposes layers: clear coat, color, primer, and sometimes metal or plastic. Each layer has a thickness step. If you don’t taper those steps, your repair will show as a ridge under new paint. Proper feathering (1) removes loose material and rust at the damage, (2) creates a shallow, even ramp across layers so primer can level, and (3) tightens the scratch field so high-build primer grips and sands smooth without sink lines.

Tools & Supplies

• Wet/dry sandpaper sheets: 80, 180, 320 (optional 400–600 for post-primer blocking).
• Firm mini hand block (1–3 in.) and a thin soft foam pad for gentle contours.
• DA (dual-action) sander (optional) set low for larger scuffed areas—hand control is safest near edges.
• Masking tape and masking paper/plastic to stage a clean working window.
• Guide coat (powder or light mist), panel wipe/IPA, lint-free microfibers.
• Rust converter (if steel shows rust), glazing/filler as needed, plastic adhesion promoter for bumper covers.
• Etch/wash primer or epoxy primer for bare metal; high-build primer-surfacer for leveling.
• PPE: nitrile gloves, eye protection, respirator; work in the shade on a cool panel.

Recommended Grit Sequence

• 80 grit: Initial shaping—remove lifted edges, rust, and loose coating; begin the taper.
• 180 grit: Primary refinement—widen and smooth the feather edge; erase 80 tracks.
• 320 grit: Primer-ready finish—tighten the scratch field for primer/surfacer and sealer.

Step-by-Step: Invisible Edge, Primer-Ready

1. Clean and stage. Wash the area, then wipe twice with panel wipe/IPA. Mask a working window around the chip—about a hand-span—so you don’t pepper dust onto adjacent panels.
2. Assess the damage. If you see rust on steel, plan to remove it fully (or treat pits with converter). If it’s a plastic bumper chip, check for lifted edges—plastic tears need gentle shaping.
3. Shape the crater at 80. Wrap a firm mini block with 80 Grit (25-pack) and lightly bevel the chip’s edge, working from the damage outward in short, controlled strokes. Keep the block flat; don’t dig with fingertips. Your goal is to remove all loose paint and rust and start a shallow ramp into good coating—no sharp edges left. On plastic, use even lighter pressure and shorter strokes to avoid gouging.
4. Guide and read. Dust on a light guide coat. Under raking light, the guide shows remaining high edges and 80 scratches. If metal is pitted, spot a tiny amount of rust converter (as directed) or plan a thin glaze later—don’t over-cut the panel trying to chase every dot.
5. Smooth and widen at 180. Switch to 180 Grit (50-pack) on the block. Sand a slightly larger halo around the chip, replacing every 80 line with a tighter 180 field. Work in overlapping arcs, staying flat. This step erases gouges and creates a longer, shallower taper so primer won’t sink later.
6. Fill if needed. If the crater is deep after 180, mix a small dab of glazing putty or filler. Apply thin, let it cure, and block it gently with 180 until it flushes to the feathered ramp. Re-guide to confirm flatness.
7. Primer-ready at 320. Move to 320 Grit (100-pack) and expand one more ring outward. Replace the 180 scratch completely, leaving a uniform satin that blends invisibly into the surrounding paint. For gentle crowns, use a thin foam pad to keep contact without faceting, but finish with the firm block to maintain flatness.
8. Clean, then prime smart. Vacuum/wipe dust, then apply etch or epoxy primer on any bare metal. After it flashes/cures per label, cover the repaired halo with high-build primer-surfacer. Spray light, even coats to avoid solvent soak at edges.
9. Block the primer. Once sandable, block primer with 400–600 (dry or wet per system) using guide coat to chase pinholes and map flatness. Your feather edge should vanish. If you witness an edge, re-enter locally with 320 on the ramp, re-prime lightly, and block again.
10. Color and clear. After primer is straight and sealed (if required), apply base color and clear per system, blending as needed. Keep dust control high to avoid nibs.

Special Cases

Aluminum panels: Avoid aggressive 80 dwell—aluminum galls. Keep pressure light and move to 180 quickly; use epoxy primer for best adhesion/corrosion resistance.
Plastic bumpers (TPO/PP): Use a plastic adhesion promoter before primer; keep strokes short and pressure minimal to avoid gouges and fuzzing.
Deep rust pits: After 80 cleans the surface, treat remaining pits with converter, then glaze minimally. Over-grinding thins panels and warps reflections.
Multiple chips/road rash: Work one blended repair zone rather than a dozen dots—feather a larger oval, fill as needed, and prime as a unit for a smoother result.

Pro Tips

• Flat block = invisible edge. Fingers create troughs that telegraph under gloss—always block the ramps, foam only for gentle crowns.
• Fresh sheets beat pressure. The moment cut slows, rotate to a new quadrant. Pressure heats and gouges, especially at 80.
• Guide coat is truth. Dust a guide before each step. If you still see an edge after 180, you’re not ready for 320.
• Widen the halo as you go finer. Each grit should extend slightly farther than the last to blend scratches seamlessly.
• Keep it clean. Panel-wipe between steps; one rogue coarse grain trapped under paper equals one permanent scratch.

Aftercare

• Respect primer and paint cure times before washing or sealing.
• Avoid harsh cleaners for the first month on fresh resprays; use pH-neutral soaps.
• If tiny sink marks appear after cure, a light 1500–3000 wet polish and a finishing compound can restore the surface—keep it cool.
• Touch up stone-prone areas with protective films or guards to prevent future chips.

FAQs

• Can I start at 120 instead of 80? Yes, if the chip is shallow and edges aren’t lifted. If the ridge persists at 120, drop briefly to 80 to break it, then continue.
• Do I need filler on every chip? Only if the crater remains after feathering. Many small chips taper flush with 80 → 180 → 320 alone.
• What primer should I use on bare metal? Epoxy or a compatible etch/wash primer under your surfacer. Follow your paint system’s stack.
• Why does the edge keep showing after primer? The taper wasn’t long enough or scratches weren’t fully replaced. Re-enter at 320 to lengthen the ramp, spot-prime, then block with guide coat.
• DA or by hand? Hand-blocking gives the safest control in small zones. If you use a DA to scuff the surrounding blend area, keep speed low and the pad dead-flat.

Watch & Learn

Closing: Invisible repairs come from process, not pressure. Keep the ramp long and shallow, replace scratches step by step, and prime over a tight, uniform field. Stock the exact sheets that keep you disciplined at each stage—knock down ridges with 80 (25-pack), refine the taper with 180 (50-pack), and land a primer-ready surface with 320 (100-pack). Do that, and the chip disappears when the color and clear go on.