The US Army Corps of Engineers Paint Technology Center of Expertise (PTCx) is investigating
a new method of analyzing the amount of rust creep on coatings post exposure to accelerated
weathering (ISO 12944) to determine the feasibility of increasing precision and accuracy. The
current ASTM D1654-08 recommends a ruler to measure the distance from the initial scribe
line to the edge of the rust creep region on a coated and weathered panel or coupon. Our
method utilizes a microscope and image-processing software to calculate the entire area of the
rust creep. The image processor integrates the initial state image with the final state image of
the coupon to greater utilize the amount of information produced in corrosion experiments.

A comparison of both the ASTM method and our method shows that our digitally-enhanced
process can improve the accuracy of corrosion measurement and analysis. This data-capture
process provides a possible way to improve the current ASTM by collecting more rust creep
data and introducing more automated image processing methods, thus removing human
introduced variability. The combined effect of using more information and decreasing variability
should be a more accurate quantification of rust creep.