Summary for acid copper bath Discussion
Acid copper is behaving uniquely because the bath’s acid level has climbed to 175 g/L even though no acid has been added for six months and there is no obvious drag-in; the bath also contains copper sulphate at 180 g/L and chloride at 140 ppm. Sanjeev Dania asks what could explain the rise. Guillermo Marrufo suggests the anodes may not be dissolving properly or the cathode-to-anode ratio may be too high, which could upset the bath balance. A later reply points out a likely source of hidden acid: the anode bags may be cleaned with acid, which would slowly add acidity over time. The thread does not show a single confirmed cause, but it highlights anode dissolution, electrode balance, and maintenance practices as the most likely places to investigate.
Q. The acid content of my acid copper bath has suddenly started to rise it has now reached 175 gm/l other constituents are copper sulphate
⇦ on
eBay or
Amazon [affil link] 180gm/l chloride 140ppm . no acid has been added since last six months . no drag in of acid is there, anode bags
⇦ huh? are cleaned regularly. Can someone explain this unique behaviour.
Sanjeev Dania
job plater – Delhi, India
January 14, 2009
A. Maybe your anodes are not dissolving properly or you have too high cathode to anode ratio.
Guillermo Marrufo
Monterrey, NL, Mexico
January 30, 2009
A. How are your anode bags cleaned? I bet it is with acid…
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
January 30, 2009
Q. The cathode to anode area I am maintaining is 1:2 the copper sulphate consumption is high. the anode bags are cleaned with nitric acid followed by dm water rinse
Sanjeev Dania [returning]
– Delhi, India
April 16, 2009