Summary for nickel plating voltage spikes Discussion
Voltage spikes and amperage drops in this nickel plating thread center on a barrel-plating bath that suddenly seemed to need much higher voltage, while current output fell. K.G. Kenbo said adding about 25% more water brought the system back to normal and asked whether excess nickel could cause the problem. Ted Mooney first noted that the description was unclear and asked whether the rectifier was being run in constant-current mode, what current density was used, and whether the bath had really evaporated to 75% of its original volume. He also suggested checking whether the work was aluminum. When K.G. later said the rectifier was not the issue and suspected the anode, Ted listed likely causes of high voltage/low amps: a rectifier problem, plugged nickel anode bags, or incorrect nickel concentration and pH. In the follow-up, Ted asked for more details on the anodes and noted that some anodes require filming/passivation control.
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Q. Issues with my nickel bath, recently my voltage went from normal 5 volts to 15 volts during plating I added about 25 percent more water to level it out and everything went back to normal. Could too much Nickel in the bath cause this?
K.G. Kenbo
– Texas City Texas
January 31, 2024
A. Hi K.G.,
Sorry, it’s not clear to me what you are describing. What is it that determines voltage in your setup? Normally, you adjust the voltage on the rectifier as required or desired, such that if you set it at 5V, it’s 5V; and if you set it at 15V, it’s 15V. Are you trying to plate at constant current and letting your rectifier choose the voltage necessary to do so? If so, what current density are you trying to plate at?
Also, I don’t understand how you can add 25% more water … the bath had evaporated to only 75% of its original volume? That sounds quite extreme. Is this a production plating operation (barrel or rack?) or are you a hobbyist who hasn’t used the bath for a very long time?
You aren’t by any chance trying to plate on aluminum? Thanks.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
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Q. I’m plating aluminum, the part I was plating should have plated with 5 volts and 25 amps. It plated for a few minutes before the voltage jumped to 15 volts . I added water to the bath and the voltage went back down to 5 volts. Is my bath saturated with nickel or is it the rectifier possibly going bad?
Kenbo K G. [returning]
– Texas City Texas
February 1, 2024
A. Hi,
Voltage going crazy like that certainly indicates a defective rectifier or defective contact (if contact goes bad and you are plating by constant current or constant current density (why?), then voltage will rise in effort to deliver the chosen amperage).
No point in a baseless wild guess whether nickel is too concentrated without any data on its concentration. Tell us about your zincate process please.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
A. High voltage amps going down:
1. Check rectifier-may be rectifier problem2.
2. Nickel anode bag
⇦ huh? plug up-replace bags
3. Check nickel concentration and pH
Popatbhai B. Patel
electroplating consultant – Roseville, Michigan
Q. There is an issue in my copper-tin bath: Voltage spikes and amperage drops during the plating process; the thickness is low and Cu-Sn ratio concentration on deposits should be 50:50 but the copper concentration is decreased to 10-15 and tin concentration is increased to 90.
The bath has 4 components (potassium hydroxide, potassium cyanide, copper cyanide, and potassium stannate). Could you please advise me on the bath?
Ava Bahrami
– Houston, Texas
February 22, 2024
A. Hi Ava,
I think there is little chance that your solution composition has much to do with this problem.
Almost surely you have a rectifier problem. Have you had a rectifier serviceperson attempt to troubleshoot this?
Are you rack or barrel plating? Does this happen with every load?
what happens when you plate Hull Cell ⇦ huh?
panels with this bath? Thanks.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
Q. Actually I’m sure about the rectifier. It’s barrel plating, and it is happening for all loads. I suspect there might be an issue with anode. Is it possible that our anode has become passivated ?
Ava Bahrami [returning]
– Houston, Texas
February 23, 2024
A. Hi. Perhaps I misunderstood the situation you are describing. Tell us about your anodes please. Tin anodes do require “filming” per Garden State Branch AESF “Basic Practical Electroplating, 1986”:
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
Q. Hi Ted,
my problem is in regard to copper concentration on deposit it is very low about 5% on the contrary. Tin concentration is high — it reached to 94% and thickness must be 8 micrometer but it is 3.
Ava Bahrami [returning]
– Houston, Texas
February 26, 2024
A. Hi Ava. Apologies for continuously misunderstanding you 🙂
Copper anode polarization does occur in copper sulphate plating if the copper anode dissolves too readily, producing a too-rich solution near the anode. But I am not personally familiar with it occurring in cyanide copper or cyanide copper alloy baths — but my experience is limited.
Let’s see if this becomes my 3rd strike: I would expect the problem to be more closely related to cyanide concentration or temperature than anode passivation.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.