“Touch-up” For Scratches On Clear Anodized Parts

Question:

Is there any recommended practice that you’d recommend that will touch-up scratched clear anodized extrusions other than stripping and rerunning the parts? Sometimes, due to material handling problems after finishing, there are scratches in the material surface and the parts are rejected. These are extrusions for game table frames and are 6063-T5. Appearance is critical. T.H.

Answer:

Be sure that the “scratches” are really scratches. The anodic coating is so hard that often times, if the extrusions are carelessly brushed against bare aluminum or even other metals in some way, the other metal can actually be “deposited” on the anodized surface. This can look like a “scratch.” If this is the case, most of the time the scratches can be removed by scrubbing them lightly with a damp cloth and 0000 powdered pumice, available at most drug stores. If the parts really have scratches through the anodic coating, the only way I know of that they can try to be salvaged, without re-anodizing, is to use an aluminum color spray paint applied artfully over the scratch. Something tells me that this would really not be an acceptable method due to the close proximity of the end user to your product. By far the best remedy is to institute better material handling procedures so that the parts are not scratched in the first place. This can be a common problem in anodizing plants and can almost always be overcome by the proper instruction of the people handling the parts after they have been anodized.