Nodular buildup at edges with chrome plating.

A. Generous radius and chamfer will help. Ultimately, you probably will have to look at shields or robbers to reduce the high current density areas.
If the parts are amenable, conforming anodes can be tweaked to put on a uniform covering over the entire part. You also get much faster plating with less problems. An additional benefit is less grinding.

A. Mr. Ramasayer,

Nodular Build up in hard Chrome is a specific defect in Hard Chrome Plating that may occur under the following conditions.

1) An out of balance Chrome solution?
2) A part which is Racked wrongly without " Current Robbers" to avoid very high currents reaching the sharp edges.
3) Too high a Current density for the specific component.

Usually nodules occur as a combination of the 3 factors above or at times a fourth factor.. Too low working bath temperature but that's a lesser possibility.

I hope this helps.
Regards

A. Rick,

It is the nature of the beast with hard chrome plating. The plating process is very low efficiency, you have to put a lot in to get a little out. The extremities are what we call high current density areas and consequently you get uneven growth of plating over the part. When you call up the higher thicknesses the extremities will form these nodules.

The problem can be mitigated, but not eliminated, using "robbers" or with a change in anode configuration, with orientation in the bath and with tight controls on the operating parameters. You can also try reducing the thickness called up.

What usually happens is that you call up greater than the final thickness you require and then grind back to size.

A. Edge area having high current density. So normally hard chrome will built up more faster on this area.

Using same attachment to connect on the edge to move out the high current density area.