I've been having a problem with cad plating over the last few years.
After having parts plated, within a couple of months there is a discolouration or staining that occurs.
it doesn't seem to matter whether the parts are new or old.
I have discussed it with my plater and he is at a bit of a loss. He has replated some parts but it just returns.
It will clean off very quickly with CLR but will eventually come back.
Any ideas anyone?

email (option): mfarnay@bigpond.net.au

I've experienced exactly the same problem over here in UK. (even new parts). I can only assume that as the parts are not individually processed like chroming, and that they are all jumbled together and tumbled, that not all impurities are cleaned away.

Mark, tracking shows your parcel is delivered? Ron

email (option): ronpier@talk21.com

Try to smear some silicone grease on the item. Also works for chromium and nickel.

Hi Guys,
I was an Electro plater for 10 years and used to do a lot of cad plating, Looking at the photo of the gearbox inspection cover my guess would be that the parts are not being prepared correctly, We first gave them a soak in hot degreaser (caustic soda) then Electro cleaner (same stuff with an electric charge running thru it) then a water rinse followed by a good soak in hydrochloric acid until the rust or scale has been removed then another rinse and into the plating vat for 15-25 mins, sample a piece under X-ray machine for 7 to 12 microns thickness (any more and the plating would burn) but maybe in these days of health & safety the plating solution is not the same (solution was highly carcinogenic and burn a hole in your foot or hand if you wasn't careful) so I think the problem is either prep or modern plating solution, ask your plater to put your parts through the caustic rinse after the acid rinse before putting in the plating vat sure that used to work.
Regards John(Tom)Green.

email (option): rustytomm20@hotmail.com

Thanks John. It's a strange thing. Things I had done 5 or 6 years ago are still fine. It's the more recent stuff that is the problem. Something must have changed in the procedure.
I think I will print out what you wrote and let my cad man have a look. Might be able to get it sorted out.

Nice bars Ron thanks. 😉

email (option): meck04@bigpond.com

Your welcome Mark' Hope you get it sorted,
Regards John.

email (option): rustytomm20@hotmail.com