The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Excess copper deposition in pyrophosphate bath

Does anybody have an idea what would be the reason of the following:
in pyrophosphate electroplating bath there is an excess copper deposition even to the surface of the liquid in form of lumps. Parallel the copper content of deposit (on steel wire) is growing.

Zoltan Fekete
Plating Shop Employee - Szentgotthard, Hungary
September 13, 2010

---

September 15, 2010

Hi Zoltan,

I might be able to offer some advice but I need a clearer picture of the problem.

Are you plating wire continuously (coils of wire drawn through the plant) or are you plating wire assemblies?

Have you been plating the wire satisfactorily previously and the problem has just started?

Is the deposit mainly satisfactory with some parts having lumps (roughness/nodules)? If so, where are the defective areas relative to the good parts?

The more information you give the better the chance a useful reply.

Harry Parkes
- Birmingham, UK

---

September 18, 2010

Hi Harry, Thanks you for the answer. Pl find my answers in your text.
Zoltan

I might be able to offer some advice but I need a clearer picture of the problem. Are you plating wire continuously (coils of wire drawn through the plant) or are you plating wire assemblies?

Our line is operating continuously. It is producing brass plated wires for the tyre industry.

Have you been plating the wire satisfactorily previously and the problem has just started?

Frankly speaking I do not know. I am employed only for a couple of months. But I guess the problem existed also earlier.

Is the deposit mainly satisfactory with some parts having lumps (roughness/nodules)? If so, where are the defective areas relative to the good parts?

The brownish matt lumps consist either of copper or cuprous oxide (I will check it for sure). Virtually the built up of lumps coincides with higher copper content of the brass (%) and even higher brass on wire (g/kg). We did not check if it is a throwing power problem.

Zoltan Fekete
- Szentgotthard, Hungary