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Deposit peeling on borders and showing black spots on Watts bath

Hello
My name is Daniel Hernandez, I'm setting up a small bath on my work shop (400 lts), I have an old Watts solution forgotten somewhere in my workshop and I decided to put it to work.
my situation is as follows:
I'm dummying at 0.75 amps/dm2 and the deposits peels on borders and show black spots.

what type of contaminant do that copper, zinc, chromium, nitric acid?

thanks

DANIEL HERNANDEZ
PLATING SHOP ADM - BUCARAMANGA, SANTANDER, COLOMBIA
March 24, 2009

You say that the watts bath was forgotten somewhere in your shop. Was analysis on the bath also forgotten before start up? It is very hard to tell what metallic impurities are present without checking for them. The bath chemistry itself should be analyzed, then checked for impurities. Asking a question like you did is like grasping at straws. Someone could say "it's probably lead or zinc", where the problem is low nickel metal concentration or clogged anode bags. Concrete data eliminates guesswork.

Mark Baker
Fellow Plater - Syracuse, N.Y., USA
March 31, 2009

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April 2, 2009

Thanks for your time, I think you are right.

But maybe it could be Chromium and nitric acid for black streaks
Chromium peels

both of them actuate on HCD areas

Can be another type of contaminants?

I have some photos and still waiting for the lab analysis. maybe when I got them I will post the question again

it would be useful to publish a photo with the question

Daniel Hernandez
- Buacaramanga, Santander, Colombia

Analysis results, inorganic impurities, and a photo would be a great help. In plating there can be different causes that show identical defects.

Mark Baker
Fellow Plater - Syracuse, NY, USA
April 8, 2009