Monday, March 26, 2012

Doing the work of sand: Restoring damaged aluminum castings

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.


  1. Very nice, and tanks for sharing. Could you elaborate a bit what tools you used to re-texture the case?



    1. Re-texturing the case is a most un-scientific process. We used all sorts of odd tools from nails, to punches, to scraps of metal lightly tapped with steel hammers to generate the texture. Once the texture is made, the part is lightly blasted to just knock off the sharp edges that make it look un-even. It takes a lot of time but once finished it looks 100% perfect.

  2. Very nice images you have provided about Aluminum Components Machining. But it will be more better if you will provide some information about it.

    Thank You.

  3. Great stuff great stuff mate.. after that restoration those sparkling
    parts looks so better right