Inspect, Repair, and Touch Up Finished Painted Surfaces
This domain tests the final check: whether the finished surface meets the specification and, if not, how to repair it without making a bigger defect.
Core rules
- Inspect under the specified light and at the specified distance. Check colour, gloss, coverage, uniformity, dryness, adhesion, film thickness and freedom from defects.
- Use the right instrument: dry film thickness gauge, adhesion tester or cross-cut tape test, moisture meter, gloss meter, and a wet film gauge during application.
- Classify defects before repairing: runs and sags, orange peel, brush or roller marks, holidays, blistering, peeling, chalking, efflorescence, fisheyes, solvent pop, and overspray.
- Repair sequence: remove the defect, feather the edge, clean and dust off, prime if the substrate is exposed, then recoat with the same product and batch where possible.
- Touch up by blending into the surrounding area, not by daubing a spot. Check the repair after it dries under the same light.
- Record the defect, cause, action and acceptance in the inspection report.
Worked example
A door has a 100 mm run in the topcoat. Sanding only the run will leave a dip. The correct repair is to allow full cure, scrape or sand the run back to a sound edge, feather the surrounding film, clean, spot-prime if needed, then recoat the whole door face or blend to a natural break. The reasoning is that a local patch will show as a gloss and thickness difference; blending to an edge restores uniformity.
Traps
- Touching up with a different batch or sheen and expecting an invisible repair.
- Sanding a defect without feathering, leaving a halo.
- Testing adhesion before the film is fully cured.
- Passing a surface with a holiday because it is only small.