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==Procedure==
[[File:Anodisation.jpg|right|thumb|350px|Schematic of the anodising process.]]Prepare the aluminum for anodizing by cleaning thoroughly using a fine steel wool to remove the surface contaminants and reduce imperfections. Take care not to cause micro metal contamination by pressing too hard. Note that the finish that goes into the tank is what comes out of the tank. Follow by a wash with a plastic scouring pad and washing up detergent (or 99.9% isopropyl alcohol). Rinse well and either proceed to the sodium hydroxide etch for 2 to 3 minutes and rinse again, or go directly to the anodizing solution. The etch step provides some bite for the solution and allows for slightly larger cell size. Aluminum alloys are highly variable so if possible experiment with scrap pieces.<ref name="obs"/>
A large amount of small bubbles of hydrogen will be seen at the cathode. The time required for anodizing depends on alloy composition, current draw, solution temperature, and solution concentration. Start with 30 to 60 minutes. A good indicator is that the piece will have a slightly yellow tinge as the index of refraction changes with cell growth. Rinse the completed part in cold water and place in the dye bath at room temperature. Allow about 60 minutes and rinse the part in cold water. If the color density is low, place it back in the dye bath for a longer period. When the color is correct, place the piece in boiling tap water for 20 to 30 minutes to seal in the dye. If a further protective coating is desired a clear coat of spray acrylic can be added to highlight the color.<ref name="obs"/>
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