Why You Need Anodizing of Metals

By Ron Victor

Aluminium alloys are always an excellent choice of metal for home machining. It can be used on mini-lathe to make telescope parts or camera adapters and other helpful bits and pieces. But there is an unfortunate drawback in using aluminium this way. The key advantage and disadvantage of this metal is its relative softness towards other metals such as steel. This supple nature makes it very easier to engine on a mini-lathe than steel, but, if once you have completed your part, it is very liable to tiny dents and surface scratches.

When chemically speaking, aluminium is an awfully reactive metal. We all are familiar with the action of our environment on iron. It will oxidise pretty readily to form iron oxide - or rust as more commonly known. Aluminium is highly reactive than iron, and, so, will rust more readily. Yet, with aluminium a rough coat of aluminium oxide will be formed which strongly inhibit further oxidation of the metal. Due to this aluminium is known for its elasticity in corrosive environments like car radiators or boats. In later period of time aluminium "rusts" - and slowly produce a white powdery coat.

For the aluminum industry there is a system to overcome the inbuilt softness of the metal and protects against oxidation. Using chemical process it is possible to build a layer of aluminium hydroxide on the surface of the metal that is very hard and more durable than the rough naturally oxidised film that normally forms. This process involves suspending the aluminium in acid bath and passing electric current through it. And this is known as anodizing. It is an electrochemical method that works with the porous makeup of the aluminum. This process thickens and toughens the naturally occurring protective oxide. Thus it offers a higher life span to the product. As anodic coating becomes part of the metal, it is one of the hardest substances for metal finishing. Anodizing also adds durability and color stability.

The advantage of anodizing aluminium is the latent of colored anodizing dye. It seeps into the microscopic pores of the anodized part and gives colors to it. This layer is then sealed and the color appears as part of the metal itself. This can generate great artistic effect, making aluminium parts with strikingly tasteless colors to ornament your motor bike or more topically, your telescope. With visual applications, black is the most popular anodizing color inorder to reduce the internal reflections. Of course, black is supposed to be one of the hardest colors to achieve and so the commercial black anodizing dye is fetching the highest price in the market.

Anodizing aluminium is a fairly simple process, and providing you can put your hands on the correct chemicals (sulfuric acid) it is rather straightforward to do simple anodizing aluminium in home. You could limit yourself to anodizing in fairly small amounts - but if you want to anodize a large object you require a lot of electrical power and acid, so if you want to it for an entire bike frame in one go, You can contact an aluminium anodizing company.