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Posted: 6/18/2006 6:23:56 PM EDT
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I recently bougth an "in the white" mega lower with the intention of simply using duracoate for the color of my choice. I have read elsewhere that anodizing is essential as it adds hardness. Do I need to have the receiver anodized before I duracoat it? Any recommendations would be helpful as I have some Durabake on order. |
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In the white as no color added after anodizing, or just not anodized at all. Anodizing (the outer layer formed on the metal, colored or not) has a RC of around 60 to 65, where as just a bare receiver has that of hard butter. Granted that the spray coating will buy you some outer layer protection against handling, it's the lack of the true anodized surface hard layer that may lead to the short life span of the receiver in regards to the pin holes and wear. |
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In engineering applications anodizing has several benefits. 1. better corrosion resistance than bare aluminum, especially noteworthy in marine environments 2. increased surface hardness, beneficial in abrasive environments (although in such environments there are usually better choices of material than aluminum available) 3. electrical insulation, useful in applications such as aluminum wire loudspeaker voicecoils 4. cosmetic - can be colored with dye 5. better paint adhesion than on bare aluminum 6. reduces galling of threaded joints (although it can be a chore to anodize internal threads in holes) Increases in "strength" are limited to the region near the surface. In the analogy posted above, if bare aluminum is likened to hard butter, the anodized layer is like leaving the butter in the paper wrapper - substantially harder on the surface but that doesn't turn it into a major structural member. Rockwell c 60-65 is decent, the same hardness as a good knife blade. But a bar of anodized aluminum will bend and dent far easier than a steel knife blade, because the bulk of the bar - the inside of the part - is still just plain old aluminum. So hard anodize will reduce scratches in aluminum, but not dents. |
Anodizing in it's self is a clear coat with the pores open until it is heated to seal it off. The color is added before the receiver is heated to complete the coating. Hence you can dye the anodizing any color you want, but it will need to be done right after the cold water acid rinse bath, but before the hot water sealing bath (the hot dye bath). |
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