Just as tempering makes steel stronger, anodizing makes aluminum harder,tougher. It resists scratches, dents and abrasion better. The aluminum is known as 5005. The alloy content of anodized aluminum substitutes magnesium for copper.
To anodize the metal it is passed through a series of electrolytic cells. The current and temperature are carefully controlled to achieve an oxide coating of specific thickness and properties.
All metal, even aluminum, oxidizes after being exposed to the elements. Anodizing is a method of controlled oxidation so that a uniform oxide coating is achieved. The process adds a mil or two of thickness to the 30 thousands of an inch metal. But it also impregnates the aluminum and becomes a part of it. The anodized surface is then sealed to give it permanent coloration. Scientists compare the hardness of the surface to that of a ruby. It is a satin-like finish and is non-reflective.

Aluminum Anodizes Council. click here

 

Coat the finish with sealer.
The sealer of choice is Permacoat™ 62. This product is specifically designed for aluminum and delivers excellent results. It requires proper preparation of the surface before it is sprayed on. This method gives the satin finish that appears similar to a wet surface. It is a thin and delicate coating. If you scrub aggressively or use a squeegee to dry, it can remove the finish. The finish requires little maintenance. Washing once or twice a year unless you get muddy is all that is required. If the Permacoat 62 does come off prematurely you can successfully patch that area with a rag dipped into the product. Expect the Permacoat 62 to last 4 - 6 years and that you will pay $600 each time if you have it done professionally. I highly recommend professional application. Surface preparation is the key to success. Permacoat has been applied to coaches that were brand new and those that are old. If it was applied new and re-applied during its life the Avion looks like it is brand new. Older trailers will have effective results also. Expect the finished product to look as good as when you clean and wax

Coat the finish with wax.
The main advantage of wax is cost. A carnauba wax such as Kit™ car wax is all you need. Polymer waxes are great for painted surfaces but will not give you satisfactory results on an anodized surface. Expect to wax at least twice a year as you would your car. There is a lot of information regarding different individual's success with wax on the "Avion Camping and Restoration Forum". Click here.