Metal finishing Q&As since 1989

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Concentration of chloride in semi bright nickel

What is ideal concentration of Nickel Chloride in semi bright baths? It seems to me that too high Ni Chloride ( above 30 g/l) tends to dissolve more sulfur from the anodes mainly if some types of S-rounds are utilized, which in turns, produces more soluble sulfur salts causing an oclusion of sulfur in the deposit making it bright and less sacrificial. Can anyone confirm and help me in this matter?

Thanks,

Adriano Alibune
SurTec do Brasil Ltda - S.B.Campo
2003

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Hi Adriano,

I believe most Watt's type baths run around 15 to 20 gram per liter chloride. Increasing the chloride in your bath will not oxidize the sulfur in S-nickel into sulphate or some other soluble form of S. The sulfur in S-nickel remains in the anode residue which typically assays 20-25% sulfur. What higher chlorides will do is increase the tensile stress in your plate.

Don Piett
- Thompson, Manitoba
2003