The authoritative public forum
  for Metal Finishing since 1989
  

  -----

HARD CHROME PLATING OF 10MM DIAMETER CK45 RODS

WE ARE FACING PROBLEMS IN HARD CHROME PLATING 10MM AND 12MM DIAMETER CK45 RODS OF 3600MM LENGTH. WE HAVE A VERTICAL BATH. WE INTEND TO ACHIEVE 15-20 MICRONS THICKNESS (I.E. 30-40 MICRONS DIAMETER). WE ARE GETTING TAPER TO THE EXTENT OF 0.03MM (DIAMETER) IN THE PLATING DEPOSIT. THE DEPOSIT ON THE BOTTOM PORTION OF ROD IS NIL. PLEASE HELP US OUT BY SUGGESTING A SOLUTION.

MEET V. M.
PLATING SHOP - BARODA, INDIA
2006

---

My first suspicion would be that the tank is not hot enough near the bottom. Your heating coils must be near the bottom of the tank, extending at least below the bottom of the rod. And you need good agitation.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

THANK YOU SIR. ALSO I WOULD LIKE TO KNOW THE TEMPERATURE TO BE MAINTAINED AND CURRENT TO BE GIVEN FOR SMALLER DIAMETERS. WE HAVE ANODES MADE FROM STRIPS OF LEAD+TIN. SO IS THIS KIND OF ANODE GOOD ENOUGH OR DO WE NEED TO CHANGE IT? SOME PEOPLE HAVE SUGGESTED TO USE SOLID ANODES WITH PORES IN IT. PLEASE GUIDE ME IN THESE ASPECTS.

MEET V. M.
- BARODA, INDIA
2006

The bottom portion of the rod does not have the benefit of the gas bubbles replenishing the diffusion zone the way that the top does. the anodes probably do not go to the depth of the rod. More anode surface could be added to near the bottom of the tank which should increase the plate in that area.

James Watts
- Navarre, Florida
2006