I work for a company that builds a sewer laser that’s used for putting in tile from manhole to manhole to assure a constant grade and flow with no low spots. This product is subjected to salt water, gravel, and must be durable. We offer two versions: one has a nickel plating and brushed finish with hard chrome and no powder coating. The other has a nickel plate with powder coating over it. We had corrosion problems and after much testing found that once the finish is scratched to the base metal (aluminum die cast) a galvanic reaction occurs because of the dissimilar metals of the nickel and aluminum. This corrosion happens very quickly and blisters. We have since moved to black anodize and powder coating over it, and our problems went away because the plating is much more compatible with the base metal once a scratch happens. It’s also as more durable than the nickel. I thought you might be interested in our info. If you have any questions, please feel free to give me a call. Thanks. D.D.
Your information makes perfect sense.