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Electroplating on Aluminium

September 27, 2009

Dear

I'm 29 years old electro engineer from Croatia (Europe).

First I'd like to say that this is the best site with electroplating instructions available.

I'm really interested in nickel electroplating and only metal I wanna to electroplate is aluminium due to polishing does not give surface shiny enough.

Lately I was reading alot about this technique and there is not even one article that will tell you how its done, what's the big secret? :)

So I'll be free to ask few questions

So, I'll begin

-How aluminium surface should be prepared (mechanically)?

-What kind of bath should I use to chemically clean surface.

-How material will react, will there be any problems with depositioning nickel directly on aluminium?

-Is Nickel Sulphate only bath enough to make a 25 microns layer?

-I don't wanna enyone to get cancer, specially kid next door (cant imagine day without him shooting my dog wit air rifle) and I think I' couldn't even get chromic acid so question is is there any alternative to get that blue/red shine?

That would be all, thanks in advance and best regards from Croatia.

Marin Peri
electro engineering - Split, Dalmacija, Croatia

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September 28, 2009

Hi, Marin. Part of the problem here is that nickel plating on aluminum is not secret, but is not so drop dead easy that people can explain the subject in the paragraph or two that they have time for. Can anyone reply with how to do an appendectomy or build a bridge in a couple of paragraphs? But there are plenty of books that will explain such subjects in complete detail.

1. Aluminum should be prepared similarly to the way you would prepare it for anodizing or chromate conversion coating, including non-etch alkaline cleaning, and desmutting. Then it must be zincated. Then the zincate is stripped in nitric acid, then the article is zincated again. Then it must be either copper cyanide plated or electroless nickel plated. And finally nickel plated.

2. Each of these steps benefits from highly tailored chemistry. So most plating shops will buy formulated non-etch cleaners, but you can clean with pumice [on eBay or Amazon] and a scrub brush [on eBay or Amazon] if you want to keep it simple.

3. You can't electroplate directly on aluminum, but must zincate it, and then alkaline plate it as mentioned before nickel plating.

4. A Watts nickel bath or sulphamate nickel bath is probably more promising than nickel sulphate.

5. I'm not sure what you mean by that "blue/red shine". Chrome is approximately the color of a mirror; it is not blue or red. You may be thinking of chrome-look paint.

Please see our FAQ "Introduction to Chrome Plating", and get back to us with any specific questions if the explantions were not clear. Good luck.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey