Selected Answers

From OM PRAKASH JAT of TECH INTERNATIONAL SHARJAH HAMRIAH UAE. on April 25, 2015:
Aluminum can develop a protective oxide film with ...read more Aluminum can develop a protective oxide film with low adhesion to the substrate. If coated with an organic coating, the oxide film may detach from the substrate. However, on anodized aluminum, the oxide film adheres strongly to the substrate. Lightly abrade the surface, then apply the organic coating. Surface preparation of aluminum varies with different circumstances. Sometimes, only degreasing and water rinsing are needed. At other times, wet or dry abrasive blasting with a fine-particle sand or plastic abrasive may be necessary after degreasing. Avoid creating a high surface profile. Use a vinyl wash primer or other special primers (such as a two-pack epoxy) before top-coating with an organic coating.

From TOLGA DIRAZ of Freelance on April 1, 2015:
Surface preparation and coating selection for alum ...read more Surface preparation and coating selection for aluminum are very similar to the same activities for galvanized and stainless steel. Conversion coatings and etch primers are very popular in the industry, but you need to verify the coating suitability to your aluminum grade with the coating manufacturer . As to standards and recommended practices, I suppose the link below provides a good starting point for this subject: http://metalfinishing.epubxp.com/i/49721-2011-2012-surface-finishing-guidebook/674.