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Applying color to a laser engraved graphic on a color anodized part

We are producing a small aluminium body that we are color anodizing, specifically a deep purple. We then use a 25W CO2 laser to engrave a graphic on one of the surfaces. The color of the graphic is WHITE. By this color I assume that we have only bleached out the purple and have not removed the anodic layer? If I am correct in this, my question is does anyone have a suggestion as to what I can then apply to this graphic to color it, say to an orange. Can I anodize the entire body in orange and it only color the graphic?

Thanks for any help.

Michael Smith
product engineer - Anderson, South Carolina
2004

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Hi,

Unfortunately the laser etch is not only bleaching the colour out, but the intensity of the laser would be annealing the substrate, colouring requires an open oxide cell (Process - Anodize,colour,seal) Sealing would have already been done after D/Purple finish obtained in the colouring process. You may do well to consult a screen printer to apply an orange two pack polyurethane over your laser etch.

Robert Fyfe
Audio Eng. - Wyoming, NSW, Australia
2004