Summary for activating nickel sulphamate plating Discussion
Activating nickel sulphamate plating for a chrome flash was the core issue after a flash hard chrome layer chipped from a nickel-sulphamate-plated steel cylinder ID that had been lightly ground before chrome. Darryl Lumongsod asked what preparation or etching was needed before chrome plating over the nickel. James Watts said there are many opinions on nickel activation, but the surface must be clean; he recommended acid activation, then a Woods nickel strike, followed by a rinse and immediate transfer to the chrome bath. He added that some platers prefer to go into chrome “hot” at low voltage to avoid passivation. Gabriel Schonwald gave a more detailed sequence: cathodic electrocleaning, 20% HCl or electroactivation, reverse Woods nickel strike, forward Woods nickel strike, then chrome plating with voltage on at about 2 V, possibly electrolyzing the part for 1–2 minutes first. The thread suggests poor activation or delay before chrome may have contributed to the adhesion failure.
Q. I have run a test on nickel sulphamate plating on the inside diameter of MS cylinder material. After nickel sulphamate plating, the job was given a light cut in the grinding machine to ensure smooth surface preparation before proceeding with flash hard chrome plating in the same area plated with nickel sulphamate. There is a portion in the chrome plating that chipped off after doing a flash chrome plating. What is the necessary preparation to undertake before doing a flash chrome plating on nickel sulphamate plated steel. Does it require any etching?
Thanks.
Darryl Lumongsod
– Al Quoz, Dubai, UAE
May 27, 2009
First of two simultaneous responses —
There are as many opinions on activating nickel as there are platers. It needs to be clean and your choice of acid activation. I would then give it a Woods Nickel strike, rinse well and immediately go into the chrome. Some platers will say to go into the chrome “hot” with a low voltage to prevent passivation.
James Watts
– Navarre, Florida
May 28, 2009
Second of two simultaneous responses —
!-Degrease the Nickel plated surface .(Cathodic Electrocleaning)
2-Acid 20 % HCl or electroactivation (cyanide based)
3-Reverse Wood Nickel Strike 15-30 sec
4-Forward Wood Nickel Strike 60-120 sec
4-Deep in Chrome Plating Solution (Voltage must be on at 2 Volt)you may electrolize at 2 Volt the part during 1-2 min.
5-Chrome Plate
Gabriel Schonwald
Bnei Berak, Israel
May 29, 2009
July 2, 2009
Sir, thanks a lot for your contributions. It really helped a lot. I was able to do it perfectly. Appreciate it very much.
Thanks once again.
Darryl
Darryl Lumongsod
– Dubai, UAE