Summary for iridescent staining on electroless nickel Discussion
Iridescent staining on hi-phosphorous electroless nickel is reported by Jerry W, who plates 0.001" EN on copper evaporator grids and sees a random iridescent appearance a few days after plating. He notes that the parts get a RO-water final hot rinse, and that units shipped to Mexico for final assembly seem more troublesome than those assembled in Wisconsin. The thread excerpt provided contains only the question and does not include any answers, so no cause or corrective action is stated in the source. The key issue is a delayed, uneven surface change after plating that appears to vary with handling, shipping, or post-plating environment.
September 1, 2015
Q. We apply 0.001″ high phosphorous electroless nickel to evaporator grids made from copper components. We are seeing an iridescent appearance on the nickel a few days after plating. We use RO water as the final hot rinse after plating and this condition is pretty random. We plate these evaporators in Wisconsin and ship 80% of them to Mexico for final assembly, and these seem to be more troublesome than the ones that stay here for final assembly. Thoughts?
Jerry W
Manufacturing Engineer- CEF3 – Manitowoc, Wisconsin