Over time mechanical components get accumulated marks from both use and service. Or rather between use and varying degrees of care during service. Our gearbox casing showed 40 years of such marks and, while we were lucky to have no broken bits, there were still many scrape marks and nicks that required our attention.
The original gearbox casing was cast in a sand mold that gave it its distinctive outer texture. The first step in restoring the casing was to carefully file away damage so that the rough shape of the part is restored. After this is done, hours are spent with an assortment of odd tools and hammers peppering the surface of the aluminum to replicate the natural finish once made by sand. While extremely time consuming the results are well worth the effort as the repair is not visible even under the closest of scrutiny.
One last job was to restore the original drain plugs. Again, an assortment of tiny files and a finishing using glass beads at a very low pressure achieved a factory fresh look over 40 years after manufacture.