The United States Marine Corps has experienced success employing thin water
displacing Corrosion Preventive Compounds (CPCs) for the reduction of corrosion in occluded
sites (i.e., around hinges and fasteners and under lap seams). However, no definitive test
methodology has been established that clearly delineates relative corrosion protection
requirements for the use of CPCs in occluded geometries. This work seeks to confirm the
performance of commercially available CPCs in occluded sites by establishing a correlation
between laboratory results and published field data, These findings will in turn yield a practical
means of ranking candidate CPCs as well as a plausible method of testing these CPCs prior to
application. Steel lap joint assemblies and galvanically coupled steel and aluminum lap joint
assemblies were exposed to GM9540P conditions, A correlation of mass loss data from
laboratory and accelerated outdoor exposures is presented for steel lap joints. The Washburn
method was used to determine the candidate CPCs relative ability to wick into a crevice. Mass
gain data taken from the Washburn method also provided a rough approximation of the
amount of CPC that wicks in over time and the thickness of the protective layer formed. A
regression analysis was performed on properties associated with wicking in order to determine
which properties predominantly influence CPC performance.