An investigation of the corrosion resistance on 4 and 7 yeas old cars has been performed on more than 550 vehicles of 18 different makes. Body parts from collision damaged cars have been sawn out and internal open surfaces and crevice surfaces examined from the corrosion point of view. This method allows corrosion attack to be discovered at an early stage before it can be seen from the exterior. The results show great differences in corrosion resistance between different models of car. Several of the makes in the study show heavy corrosion on crevice surfaces after 4 years in use while others have only superficial or no
corrosion at all after 7 years in use. The influence of the use of precoated materials with different thickness of zinc or zinc alloy layer on the
corrosion resistance is discussed as well as the effect of adhesives and anti-rust agents with good penetration ability into the crevices.
Keywords: Car corrosion, door hem flanges, bottom rail crevice surfaces, precoated materiel, anti-rust agents, adhesives