If some mechanical parts need to be modified and locally reworked after being treated, it is possible to process them with localized anodizing without affecting the previous anodized layer.
It is crucial that the mechanical rework reaches the bare aluminium and that the milled area is even and neat (see picture below) and that the edges are properly smoothed to guarantee the best final result.
Parts made from 7000 and 2000 aluminium alloys series are more prone to have problems after the localized treatment process, because those alloys are less resistant to the acid products present in the galvanic process, especially if they were not properly sealed in the first place. For this reason we cannot guarantee that localized treatment performed on parts we did not treat originally will always lead to optimal results.