Zinc-Nickel Plating -- Dark Deposit in LCD Area

Q. Hi can anyone help me. I have an alkaline zinc nickel barrel plant.
After a month or so each time it starts to go dark in LCD areas of nuts.
I suspected the titanium barrel clamps may have been touching the anode plates as well.
Not sure if it's contaminated
16v rectifier 800 amps
It's definitely not pre treatment [problem].

Just wondering if anyone has experienced this.
There is also a lot of black sludge in the filter and tanks (all clean now).
Chemistry all in spec ratio.
Any help would be appreciated.
Also taken the plates out at the bottom now.

The bottom anode plates had zinc on them as well, only on the edges

Thanks

61702-1a 61702-1b 61702-1c 61702-1d 61702-1e 61702-1f 61702-1g 61702-1h

61702-1k 61702-1l 61702-1m 61702-1n 61702-1o 61702-1p

Darren ogden
- Manchester
August 4, 2024

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