Anodizing is a process that increases the thickness of the natural oxide layer on a metal’s surface. Aluminum oxides readily and is the most commonly anodized metal. Anodizing aluminum increases its corrosion resistance and improves the adhesion of its surface, making it easier to apply paint. The oxide layer created by anodizing can also be given a desired color. This method of coloring aluminum is generally more durable than simply painting it since the metal itself is colored.
1. Make a negative ground for the anodizer. Form a round loop with one end of the aluminum wire and cover it with the foil to make a flat, round shape. Fill the rubber bucket with a solution 70 percent acid and 30 percent water. The solution should be deep enough to cover the aluminum part completely.
2. Clean the aluminum part. Put on the rubber gloves, mix 1 to 2 oz. nitric acid in 1 gallon of distilled water and soak the aluminum part in this solution. It is vital the surface of the part be completely free of all contaminants. Clean the aluminum just before anodizing it, as the fresh aluminum surface will oxide quickly. Rinse the aluminum part with distilled water thoroughly. Place the part in the bucket with the acid solution.
3. Clip the battery charger’s negative lead to the negative ground you created in Step 1, and place it in the solution. Make sure the negative ground only touches the solution, not the aluminum part. Attach the battery charger‘s positive lead to the aluminum part and turn the charger on.
4. Allow the solution to anodize the aluminum part for about 15 minutes and turn the charger off. Disconnect the leads and rinse the part in cold water.
5. Mix a strong solution of dye and water in the cake pan and place the part in the pan. Put the pan on an oven burner and turn it to the lowest heat setting. Turn the part every few minutes to get a slightly darker color than you want. Place the part in clean, boiling water to seal the surface of the aluminum. The boiling water will remove some color from the aluminum.