Acid Wetter vs. Acid Inhibitor

In the process of electroplating of most ferrous substrates the pretreatment is extremely important since this is where it all begins. The pretreatment process is the foundation to the rest of the process being successful.  Improper pretreatment may lead to poor plate coverage, poor adhesion, premature corrosion failures, and the list goes on.  In the ferrous pretreatment process the typical process consists of an alkaline soak clean to remove surface soils such as cutting and lapping oils, stamping lubes, buffing compounds, heat treat oils, and rust preventatives. The soak clean provides for … [Read more...]

Hexavalent to Trivalent (and Back Again)

As the demand for non-chromium protection of zinc and zinc alloy plating has increased, trivalent chromium passivation systems have appeared. Early on, an interesting phenomenon was observed: Hexavalent chrome was found on coatings that were not supposed to contain hexavalent chrome. It was thought that the processor must be cheating and using hexavalent chrome in the working solution in order to achieve increased corrosion resistance. While all of the questions have not been answered, there are some conclusions. Before explaining the various parts of this mystery, it's important to … [Read more...]