This research program aims to develop a process to replace the current technology of chromating used as a pre-treatment to promote adhesion to aluminium. Plasma polymer coatings offer the opportunity of replacing the environmentally hazardous chromating process with clean plasma deposition. Radio frequency plasma deposition of plasma polymerised acrylic acid (ppAAc) coatings will be used to impart a stable acid chemistry to aluminium, to facilitate strong and durable covalent bond formation with adhesives. To develop an understanding of the chemistry and morphology of the coatings and how these relate to the deposition parameters we will carry out chemical surface analysis (XPS, SIMS and ATR-FT IR) and atomic force microscopy upon the coatings. The stability of the coatings will be probed through solvent washing. The effect of ppAAc coatings upon the adhesion of joints formed with epoxy based adhesives will be tested using the lap-shear test and surface analysis fractography.