Clean the aluminum thoroughly with detergent and water
Degrease the surface with acetone or alcohol
Etch the aluminum in a sodium hydroxide solution
Rinse the part with water
Desmut the surface in a nitric acid solution
Rinse the part again with water
Prepare an anodizing bath using sulfuric acid and distilled water
Place the aluminum as the anode in the bath
Use a lead, aluminum, or titanium cathode
Connect the power supply and apply direct current
Maintain the bath temperature and current during anodizing
Leave the part in the bath until the desired oxide thickness forms
Remove the part and rinse it with water
Dye the anodized surface if color is desired
Seal the anodized layer in boiling water or sealing solution
Dry the part completely