This invention relates to the formation of a hydrophobic and usually oleophilic coating on an aluminum surface by mechanically deforming or upsetting the aluminum surface to disrupt the natural oxide coating in the presence of alkaline agents and a long chain aliphatic carboxylic acid or other equivalent long chain aliphatic carboxylate compounds. Preferably, the carboxylic acid and alkaline agent are incorporated into a metal-working lubricant which is maintained on the aluminum surface during fabrication, such as rolling, so that the hydrophobic coating is formed simultaneously with fabrication and thereby avoid the necessity of a separate coating operation.