Is this a valid technique? (Color application to metal)

[Tristan Lall]

Originally Posted by sanddrag

My understanding is that it is not a covering at all. Strong chemicals alter the chemical properties of the metal changing its color for the first couple thousandths of an inch or so.

The anodized layer itself is not coloured--that is a dye added during the process (for example, Bosch structural extrusions are clear anodized 6063-T6 aluminum). It hardens the metal surface, but doesn't penetrate very deeply into the substance. The colour is certainly not all the way through.

Maybe what they're thinking of is a process like electrostatic paint application (similar in concept to powdercoating), where a conductive liquid paint with an electric charge is sprayed at a grounded object. The attraction increases the transfer efficiency of the coating, but doesn't produce any unusual effects w/r/t the metal's structure. Once again though, this doesn't much fit what they're describing.