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I understand the anodising process. It is not a coating like paint.. It's etched with electrolysis (spell).
That is correct !
But none theless anodising is still a coating think that's where you didn't understand what I meant, scratch that coating & you expose the alloy no different to having something chrome plated the process is still called electoplated but scratch the chrome coating & whats exposed ??
The steel , alloy , brass etc & in the case of it being steel rust , brass will tarnish etc etc
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I can have 7 Different lengths of the same shape of extrusion and after they are dipped in the tank @ the same time, for the same duration.. we have 7 different shades of metal
Yep & like you said if those lengths aren't from the same batch colour will differ, so will if the wall thickness's aren't the same
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Obviously not in powdercoat though
Nope powder coating is just paint & only way colour will differ is if colour match on the paint is not the same & if I recalled powder coating has another name
Electro Static metal is conditioned to make it static to the paint have seen it done but that was many moons ago