Expert Appraisal Guide
Checking paint on a used car is not just about looking at the micron value on the screen. Panel differences on the same vehicle, the physical condition of the surface, and bodywork marks must be checked during the same inspection.
Measurement Equipment
Keep Fe/NFe measurements on steel and aluminum panels, minimum-maximum values, and repetitions on a single device.
Device measurement is part of the expert appraisal; it is not a purchase decision on its own.
Quick comparison
| Finding | What does it show? | What does it not show? |
|---|---|---|
| Micron difference | Change in coating thickness | Definitive evidence of part replacement |
| Panel gap | Comparing paint measurement to reference | The complete vehicle history |
| Edge/joint mark | Suspicion of disassembly or repair | Repair date alone |
| Report | Measurement and observation record | Legal outcome outside of expert appraisal |
Decision guide
Do not evaluate steel and aluminum parts as the same surface type. Note the hood, roof, door, fender, and trunk lid with their position on the vehicle; NFe measurement is used for aluminum parts, and Fe measurement is used for steel parts.
Decision guide
Comparison of the left front fender with the right front fender, front and rear door, or adjacent panel can be more revealing than a single absolute threshold. Take repeated measurements from clean and flat areas close to the same spot.
Decision guide
A high measurement may be related to repaint, thick clear coat, putty repair, or surface geometry. The measuring device does not differentiate these possibilities. Panel edge, paint transition, waves, sanding marks, bolts, and inner door connections are also observed.
Decision guide
Instead of a single-word note like 'Repainted,' write the measurement range and physical observation. For example, the panel name, Fe/NFe, the minimum-maximum value of five measurements, and the observed joint mark can be kept in the same record. This method also shows the buyer the limits of the measurement.
Frequently Asked Questions
A single micron threshold is not a reliable decision rule for all vehicles. The vehicle, panel, manufacturing method, and measurement conditions vary; comparative measurement and physical inspection are required.
A difference in thickness can suggest putty or repair suspicion; the device does not classify the material as paint or putty on its own.
Related pages
Technical Resources
Technical information checked with sources on 2026-10-06.
Related products
The Habotest HT616 is a rechargeable device that measures paint/coating thickness on automotive bodywork and metal surfaces with automatic Fe/NFe recognition.