Plating die cast drum hardware

[JoeMig]

Can anyone give me some suggestions?
I'm trying to plate some die cast drum hardware with Black Chrome.
I bought the plug-n-plate nickel/flash copper combo kit, along with a bottle of the Black Krome solution.
I've applied the flash copper with success, but I cannot get the nickel to plate. The last time I tried, the plating came out kind of streaky and not smooth.
I tried to clip the anode to the side of a glass and dipping the part in the solution. I also heated the solution-this gave me the best results so far.
But still I get the streaky look. Do I need to agitate the part in the solution?

Thanks
Joe Migliaccio

[dadkar2]

I'll say that this is probably a question for Caswell's Help Line, but I'll give you my thoughts.

Using the process you have in place, take a piece of copper plumbing about the size of what you're plating (if possible). Clean it, pickle it, etc. just like you are doing to your parts. Then nickel plate it the way you've been plating your drum parts. If it streaks, then there is a problem with either your cleaning or nickel plating process. Caswell's new nickel formulation is capable of plating nickel beautifully every time, if it's done correctly.

If it doesn't plate you might want to make sure you have enough air agitation in the plating tank. A professional plater once suggested to me that there should be so many large, aggressive bubbles that it looks like the solution is boiling.

Make sure the cleaning process is good enough to pass the waterbreak test. When you dip it in your rinse after cleaning, it should retain water like the water was painted on. There should be no beading or breaking of the water film. If it does, it won't plate well or will peel off later.

Make sure the current you're using is in the neighborhood of 80-100mA per square inch of surface area you're trying to plate. What kind of power supply are you using? How are you controlling the current?

One last suggestion on the nickel: If you just mixed the solution, you should plate a dummy (like the copper pieces I just mentioned) at the recommended current density for about an hour to plate out any inpurities in the mix. I found this makes an enormous difference after a new batch is mixed.

If the copper plumbing piece plates fine, then it is very possible that your pot metal plating process is yielding voids and pits. The copper has to be 100% coverage. Any openings in the copper will allow the nickel solution to attack the pot metal. This will cause very ugly streaks that may not polish out. That's one of the reasons pot metal is such a b**** to plate. Check out my previous posting as well as 48Buick's posting on plating pot metal. It is the biggest challenge of any base metal we know of. We have both posted extensive outlines of processes for various types of parts.

Ken.