Frequently Asked Questions about Anodizing

Why anodize aluminum ? Aluminum , like steel, will oxidize and corrode. Some type of surface treatment is necessary to protect the aluminum whether it be painting or anodizing. Anodizing does not change the dimensions of aluminum hardly at all, plus it does not change the weight of it substantially like paint does. Anodizing is a process that alters the crystalline structure of the surface thus making it corrosion resistant , non-conductive, and harder to scratch.

Will colors fade ?Aluminum that has been dyed with organic dyes are subject to fade. Some colors are better than others but in time they all WILL fade. Some processes like electrolytic coloring will retard fading tremendously.

What can I do to give aluminum a chrome look? To give aluminum a chrome look, the parts can be buffed, brite-dipped, or electropolished. All three methods have their own characteristics, but to achieve a really high gloss chrome look, the only surefire method is buffing. Britedip and electropolish will chemically polish the aluminum to a good high gloss reflective finish.

Does an anodized finish last? An anodized finish will last for years and years without degradation.

Is hardcoat really as hard as steel? Absolutely ! The hardness of properly processed aluminum will exceed tempered steel in many cases. The Rockwell hardness of hardcoat aluminum is from 60-75.

Will anodizing remove scratches? Nope ! If you can feel the scratch, etching and anodizing will not remove it. Etching prior to anodizing will remove some surface blemishes and other slight imperfections but not deep scratches.

What will give my parts a uniform matte finish? Your parts can be given a deep etch and will look quite different than the normal etch. Keep in mind that for every minute that you etch aluminum , you will lose approximately .0004 inches of all surfaces.

What is electrolytic coloring ? Electrolytic coloring is a process of coloring aluminum in bronze tones that will outlast conventional dyeing by years! The coloring is achieved through processing in a separate tank containing propriety chemicals that contain base metals such as tin,copper,etc..

How much change in dimensions can I expect if I get a part anodized? Very little actually. If a part is anodized to achieve an anodized layer of .001 inches, the actual dimension change per surface may be less than .0005 inches. Etching removes some of the surface, but anodizing replaces some of it. If the parts to be anodized are going to be press fitted into another part, you MUST tell the anodizer that information. Otherwise, your parts will be scrap in all probability.

What can I do to remove anodizing? Removing an anodized surface should be left to the anodizer but it can be removed by submersing it in a proprietary stripper made for that purpose or you could take a chance and use sodium hydroxide ( Not recommended)

If a part has been anodized before, can it be reanodized ? Absolutely ! However, the first time aluminum is anodized you will be working with virgin material. After anodizing , the aluminum is never exactly the same. But, it is done all the time with good results.

Does anodizing change the color of aluminum? Not substantially. If the part(s) are left in the anodizing bath for a long time, the parts will start to take on a grey color. The color that you will end up with is based on the alloy of the aluminum. In some cases the color may be a dark grey, light grey, or even a light green.

What effect does the type of alloy have on the finish or color? Different alloys can have an effect on the color depending on what process you are using. In most cases, the standard clear aluminum finish will be similar for all alloys . But if you want a deeper anodic coating, the clear color will be altered. As for dyeing, some alloys are better than others, some a great deal worse.

Can other metals be anodized? . Metals that can be anodized include aluminum, magnesium, titanium, and zinc. Also most of their alloys can be anodized.

AAA ANODIZING & METAL FINISHING, INC

423-538-3406 FAX 423-538-3414