Through an anodizing process, aluminum is made stronger and more durable by being placed in an acid bath. Invented in the 1920s for military use, anodized aluminum became popular in architectural applications in the 1960s and 1970s because of its bright colors and inexpensive cost. Anodized aluminum is used today in cookware, home decorating, electronics and sporting goods. In all applications, anodized aluminum provides resistance to corrosion and a surface that allows for better adhesion of glue or color applications. Sometimes, however, you might prefer to remove the anodizing to reveal the original alumium surface. Does this Spark an idea?
1. Pour water into a heat-resistant metal bin or a tub large enough to submerge the aluminum part you are stripping.
2. Put on safety glasses and rubber gloves. Mix 1 gallon of phosphoric acid into your container for every 4 gallons of water.
3. Clip a thermometer to the side of the container. Heat the water to 200 degrees, using a gas grill or a propane-operated torch.
4. Fully submerge the aluminum part into the heated chemical mixture, using tongs to reduce splashing.
5. Remove the part from the water after three minutes. If anodizing is still present, put the part back in the water for another minute, or until the anodizing is fully removed.
6. Rinse the treated aluminum part with clean water from a hose or faucet to remove all traces of the phosphoric acid.