Potmetal

We Plate Cool Stuff !

We do Chrome restoration. Most of our work is classic car trim replating. We replate an assortment of old car parts like headlight bezels, hood orniments, and interior and exterior chrome trim pieces. We do the usual motorcycle and custom fabrication chrome plating and we replate a few antiques also. But our area of expertise if you will, is pot metal chrome restoration. Pot metal is the term used for castings made from an alloy of zinc and a half dozen other metals. It was used extensively for car fittings like door handles, instrument bezels, radio knobs, and most of the decorative chrome trim associated with collector cars. It is particularly difficult to plate because it not only corrodes at the surface, blistering the chrome, it has a certain ammount of corrosion internally also. For many of our high end restorations, we have to drill out pits and cavities kind of like a dentist does when filling teeth. Pot metal and Aluminum are pretty active metals. They react with both acids and alkalies and many platers avoid them because of the risk of catistrophic failure.     Replating is very labor intensive work. It first requires removal of the old copper, nickel and chrome, as well as rust, corrosion and assorted oxides. Then deep pits have to be filled with some kind of metal compatible with the substrate. After that we sand and begin building up the surface with copper. We plate and sand and plate and sand the whole thing untill the surface is smooth. Then the part is nickel plated to a bright shine and a thin layer of chrome is applied on top.     Chrome plating doesn't work like dunking a part in a bucket of paint. Electroplating involves suspending a part in an acid or alkiline bath and passing a current through the part to attract atoms of the disolved metal in the solution. A quirky thing called current density comes into play. The part's shape determines how much plating goes where. A ball shape plates pretty evenly but a box shape gets a lot more plating on the edges and corners than it does on the flat surfaces. In a mass production environment special fixtures can be made to equalize the current density of complex shapes, but single piece plating is limited to parts that plate fairly evenly.     There are limits on what can be done that are inherent in the makeup of the casting. Zinc Diecast varies in composition metalurgicly a bit to begin with and most of the pot metal we work on has had time to erode some. "Its kinda like a box of chocolates. You just never know what you're gonna get."      At one time I invisioned this website as a really cool artsy craftsy project that was going to showcase our work and expertise. As it turned out, we got busy and there never seems to be enough time to work on the website.

Questions?       Just Call Chuck        815-389-4700