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Ovality in hard chrome plating of inner diameter of cylinder objects

September 8, 2009

Dear Friends,

I have been hard chrome plating inner diameters of pipes.I face a regular problem of difference in horizontal and vertical thickness obtained in plating.Please advise if there is any specific journal for plating in Inner diameters of long cylindrical objects.

please also advise of Electroless Nickel boron is a suitable replacement to hard chrome.

Gaurav Kumar
plating shop employee - India

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First of two simultaneous responses -- September 9, 2009

An internal anode will be required to get a uniform plating. Standoffs with tiny points will be needed to center the anode. The anode will need to be sized properly to able to carry the current load.
The anode probably will need to be masked off at the top and the bottom to prevent excessive plate on the ends. This involves educated guesses and trial and error.
Are you grinding afterward and what are your tolerances.

James Watts
- Navarre, Florida

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Second of two simultaneous responses --

You need to give more details about what you are doing - sizes, lengths, volumes and processes.
Regarding electroless Ni-B, it may be suitable, but you need to say what it is to be used for.

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK
September 10, 2009