Watch Plating 101 Primer 01 02 03 04 05 06 07 08 09 10 11 12 13 14

Factors

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factor 3 - Adhesion of the gold plated layer: This is getting into territory that is harder to control, and relies heavily on the best practices, judgment and skill of the electroplater. The purpose of including this information in our discussion is to raise the readers overall awareness.

Watch cases (except for solid gold types) are made out of brass or some type of copper/bronze alloy. Some watch cases are nickel. Brass and its alloys have a tendency to oxide and tarnish very quickly when exposed to normal environmental conditions. Protecting it from discoloring is one of the reasons the watch case was goldplated in the first place.

Contaminants from oxides formed on the brass watch case can prevent good adhesion of the goldplated layer. Before a brass watch is replated, all of the worn out gold plating and surface oxidation must be removed. The brass surface must be carefully refinished and repolished. Prior to the plating process the surface must be free of any oxides or contaminants. The cleaner the surface the better the adhesion. One of the things that is often overlooked during this phase is the microscopically imbedded contaminants in the watch's outermost surface layers. This normally occurs during the final polishing steps and cleaning just prior to the plating process.

Any contaminant in the form of abrasive grit, polishing compound, soap residue, or oxides on the brass watch case can adversely affect surface adhesion. By adhering to careful cleaning processes, the electroplater can overcome most adhesion issues by submerging the watch case in a light acid rinse to remove any oxide films and to activate it's surface area. From this point great care must be taken to avoid any recontamination from quick forming oxides, fingerprints or oils during handling prior to the final plating process.

Lack of good adhesion is one factor in replating that can often lead to surface porosity or blistering in the goldplated layer.

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