Taking plating technology to the airplane

The water heated anodizing tool was wrapped with white Scotchbrite® and was saturated with the chromic acid anodizing gel by forcing it into the cover material with a spatula. The gel is thixotropic and becomes more fluid when it is actually being used. The tool was then set aside to warm up to the 95 to 105 F operating temperature required for the job.

Electrical contact was then made on a noncoated, conductive area several feet away from the defect area. The power pack was set to 38 volts, and the defect was then anodized by slowly rubbing the saturated tool over the defect area for 42 minutes. When the anodizing process was completed, the area was rinsed and unmasked.

The scratch itself was only slightly lighter in color that the adjacent anodized coating. An organic dye was used to slightly darken the scratch to a near perfect match with the existing anodized coating.