What is a paint thickness test on a car?

A coating thickness gauge is utilised to test the coating thickness of ferrous and non-ferrous metals (otherwise known as magnetic and non-magnetic metal surfaces).
Ferrous metals include;

• Steel panels
• Iron chassis and engine blocks

Non-ferrous metals include;

• Aluminium panels
• Tin panels

When conducting an inspection and a piece of equipment, we are able to determine not only the thickness of the subject panel coating (i.e paint), but to determine whether there are any underlaying imperfections that we cannot see to the naked eye.
These imperfections include;

• Body rust
• Chassis rust
• Body filler
• Substandard welds
• Rust plates
• Fish plates
• Sand blasting
• Primer thickness
• Body deadener

All of the above mentioned are crucial factors in determining if the subject vehicle deemed as being safe with no other unexpected pre-existing damages or repairs.
In short, a coasting thickness or paint thickness test is crucial when completing vehicle inspections. No matter if it is for a pre-purchase inspection, warranty inspection or repair dispute inspections.