If you are seeing nickel delamination, most likely the parts are losing their connection while in the nickel bath. If it is the whole barrel, I would check the barrel contacts. If it is only a few parts within the barrel, I would either add more load weight, investigate new danglers, or slow down the barrel rotation.
If you want to make your deposit more uniform, you can reduce the amount of nickel metal in the bath. The higher the nickel metal, the more efficient the bath is a high current densities, and the easier it is for the bath to build up larger thicknesses. Increasing load weight and/or rotation speed can also help increase uniformity. You can also try adding some brighteners, which on the small scale, can help reduce the buildup of metal in the high current density areas and preferentially deposit in the low current density areas. Although brighteners can also make the deposit more deposed toward passivation, which could make your delamination issue worse. A lower current density can also help make the parts more uniform, although you will have to plate longer to get the same amount of nickel deposited.
-Dustin Gebhardt,
CEF
Plating Engineer
Danaher Tool Group
Gastonia, NC
