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Cloudy CADMIUM Plating

We are currently experiencing a cloudy type deposit at normal current densities in a cyanide cadmium rack bath. All bath parameters are within suggested guidelines. We do have zinc at 351 ppm and copper at 24 ppm, but don't feel that is the problem, because our bbl tank has comparable contaminant levels and isn't showing the same problem (we bbl plate zinc die castings). A 1/2 amp / 5 hull cell panel looks great but a 1 amp / 5 looks terrible. We have tried HCD dummying and dilution without much help. We don't appear to have rectifier or buss problems. Any thoughts or ideas?

Jon Phillips
plating shop - Mpls., Minnesota
1999

Jon, dummying should be done at low current density with a corrugated dummy cathode. It is probably two problems. I don't like the copper at 24 ppm and it could be organic contamination as well. Are you using a proprietary cadmium brightener? Virtually all have a very small amount of nickel. All proprietary cadmium brightener suppliers have the brightener available with the nickel left out. Have you contacted your vendor and asked them for help? What temperature is the bath operated at? Have you tried adding some 35% Hydrogen Peroxide to the Hull Cell? (organic trouble). What is the analysis-very important! Bath may just need additions.

Bill Hemp
tech svc. w/ chemical supplier - Grand Rapids, Michigan
1999

Refrigerate 1 gal. of your cadmium solution overnight. Next morning carbonate should have precipitated out; do a hull cell test to see if the problem has been solved.

Gary Patigler
- Richmond, California
1999