In this paper, a review of several process solutions, examining coolants, solvent cleaning, alkaline clean/etch and deoxidizing/desmutting, listing intended and unintended chemical reactions along with possible mechanisms that would favor corrosion formation. by  W. John Fullen, Boeing Research and Technology & Jennifer Deheck, Boeing, Seattle, Washington, USA Editor’s Note: This paper is a peer-reviewed and edited version of a presentation delivered at NASF SUR/FIN 2014 in Cleveland, Ohio on June 10, 2014.  A printable PDF version is available by clicking HERE. Aluminum corrosion is commonly encountered when performing chemical process operations involving surface finishing, predominantly in preparation for paint application.  The protective oxide film of aluminum is only stable in a pH range of 4.5 -8.5.  However, many process solutions intentionally exceed this pH range for the purpose of cleaning, metal removal and subsequent smut removal.  These process solutions are formulated so as not to cause deleterious pitting or preferential etching.  However, the susceptibility of aluminum to pitting depends on many extraneous factors, such as chloride ion concentration, pH con...