8. Nickel-Anode Placement, Racks, and Contacts

Anode placement

Aim for reasonably uniform electrical geometry around the work.

General rules:

• Keep anodes parallel to major plated surfaces where practical.
• Avoid placing a sharp part edge extremely close to an anode.
• Provide anode coverage for recessed or shielded regions when needed.
• Keep spacing repeatable from load to load.
• Do not allow anodes to contact the cathode/work.

Unequal spacing produces unequal current distribution.

Anode bags

Where specified, anode bags help keep anode-generated solids from reaching the work. Keep bags clean and solution-permeable.

Rack design

A production rack must provide:

• Low-resistance electrical connection
• Mechanical security
• Repeatable orientation
• Minimal contact marks
• Drainage
• Minimal solution traps
• Adequate spacing between parts

Contact design

A dirty or weak rack contact creates resistance. Symptoms include low total current, intermittent plating, dark contact areas, heating at the connection, or one part plating differently from the rest.

Clean contact points routinely. Do not rely on a visually touching connection.

Shields and thieves

Where geometry produces excessive edge thickness, experienced operators may use nonconductive shields or conductive thieves/robbers to modify current distribution. Validate these changes with thickness measurements.