I-Fin AL AC 21 Description Application: Non-flammable, acidic liquid concentrate blended with specific surface-active agents, specially formulated for use in the pre-treatment cycle of aluminum alloys prior to anodizing &/or chromating process to remove the scales & also, oxides from the treated surfaces. The Growel Advantage: Its intelligent blend of surface active agents aids in cleaning, conditioning & activating the surface of Aluminum and its alloys. get a quote