Anodising aluminium is the only way to permanently colour its surface. Not only is the colour permanent, but it also strengthens the surface of the aluminium and prevents oxidisation and corrosion in the future. Colouring aluminium gold does not require a trip to your local metal shop however, now you can do this in the comfort of your own well-ventilated garage, saving you lots of money and preserving your aluminium for years to come.
Clean the piece of aluminium you wish to anodise thoroughly with dish soap, followed by a degreasing agent to remove any particulate matter from its surface. Try to clean the piece as completely as possible, any dirt or residue will not be dyed uniformly, creating an imperfect anodise job.
Submerge the piece of aluminium in the desmut solution. Fill a polythene tub with enough desmut solution to completely submerge it, and leave the piece of aluminium there for about 2 minutes. Heating the solution to approximately 60 degrees Celsius will make this step more effective.
Fill another polythene tub with one part distilled water and one part sulphuric acid, slowly adding the sulphuric acid into the water, never the other way around. Make sure there is enough liquid to fully submerge the piece of aluminium.
Connect the negative lead of your power supply to an aluminium plate and submerge it in the acid/water solution.
Connect the positive lead from your power supply to the piece of aluminium you wish to anodise using a length of aluminium wire and submerge it into the solution. Be sure there is no physical contact between the positive and negative leads.
Turn on the power supply and set it to output 12 volts DC at around 2-3 amps. Leave the power supply on, and the piece of aluminium submerged for 1 to 2 hours or until no more bubbles are seen forming on the aluminium (cathode) plate.
Mix a half gallon of distilled water with 4 tablespoons of gold anodising dye in a metal pot and heat it to around 37.8 degrees Celsius. Allow the piece of aluminium to soak in the heated dye solution for about 15 minutes or until the desired shade of colour has transferred to the piece of aluminium.
Remove the piece of aluminium from the dye solution and then boil it in a pot of pure distilled water for 30 minutes to help seal the surface of the aluminium. Remove the aluminium, it is now ready for use.
Changing the amount of current flow in the acid solution, as well as the temperatures in the other solutions, will increase or decrease the amount of colour transferred. Experiment with different levels to attain the desired results.
Keep some baking soda close at hand to neutralise any acid spills. Always wear proper safety gear when anodising, especially when working with acid. Contact your local waste management company for details on how to properly dispose of acid and dye solutions.