Thread: Electroless nickel plating?

I have no experience of nickel plating without electricity, but a little with it.
I was taught that a copper layer underneath nickel, contrary to what might be assumed, actually tends to promote corrosion later. Why then is it sometimes done? To improve adhesion in some cases, and also to fill in surface imperfections, according to my teacher, a metallurgist.

Jordan

My brother has done electroless nickel, so I will send him this link and see if he wants to reply.

Nev

Copper plate is the metal plating equivalent of polyester bog - it's used to build up and smooth out surfaces as it can be polished to a mirror finish quickly and easily.

It can also be used to 'tin' (as in soldering) many materials that would otherwise be hard to plate (orchid flowers in Singapore are gold plated by first soaking them in copper sulphate to make them electrically conductive, then copper plating them, then gold plating the copper).

The surface finish will generally match the appearance of the part. If it's sandblasted, you'll get a frosted look; if you've mirror polished it, you'll get a bright and shiny part.

You're not going to get any miraculous surface improvement happening (unless you get into electropolishing, but that's a whole 'nother story) so if you part has rust pits when you start, it'll have nickel plated rust pits when you finish. (Unless you bog 'em up with copper, polish smooth, etc etc etc)

Thanks for that MS. I'd never really thought about the reason for the copper coating. It was one of those take it for granted things. The "bog" analogy works. Now I understand why it is there.

Bob.

The short answer from my brother is don't bother trying electroless nickel at home. The long answer is too long and technical to post. Basically it will cost thousands just for a home setup, if you want to do it right.

Nev

I don't think you need spend thousands for the electrically-applied nickel system. But, if you want to do it regularly, you'll need to have enough space dedicated to plating. A friend had a setup using black rectangular plastic boxes with lids - similar to those seen at fishmarkets. I think he had 3 or 4 of them in a row, for the various baths. You can't easily pack up this stuff in a suitcase.

Jordan

Small setups are a waste of time. You need a fairly large quantity of solution so that you do not need to constantly make additions, to keep the solution working properly. Small quantities require constant maintenance otherwise they stop working. Sure you can setup a small one, but it's just not worth it. My brother has done plating of all sorts, for many, many years and he knows what he is talking about.

Nev

I'm sure this has popped up just recently on this forum. Although not electroless, there are a number of You Tube videos on home nickel plating. The guy makes it look so simple. What concerns me is what he doesn't say. For example, polishing procedures and disposing of the bath afterwards.

Anyway start here, and you can work through his videos if interested.

[ame=http://www.youtube.com/watch?v=Lcz8Py7bjzQ]YouTube - Nickel Plating Made Easy (Part 1)[/ame]

Ken

Disposal - chuck in some scrap steel to plate out all the nickel, let the rest evaporate and turf with the trash.

As for polishing - the hard work is done before you plate. You're not going to get a bright finish by plating alone, you need a good surface, and then a final polish by hand if you are going for a real shiny look.

Electroless nickel is better for small parts with lots of fiddly bits - you don't get shadowing and uneven deposition with the electroless process. It seems to be one of the favourites of US gun fanciers.

Originally Posted by neksmerj

What concerns me is what he doesn't say. For example, polishing procedures

We found a couple of excellent polishing products:
Lea-C
FerroPol MG

bought from:
Australian Industrial Abrasives
Prospect
9636 8644

Lea-C, applied to a felt wheel, is good for polishing steel to a satin finish.
Neither were expensive.

Jordan

I have used both electro and electroless processes.
For decorative plating, after cleaning and rinsing processes I used a BRIGHT hard copper solution to obtain a mirror finish and then rinse and straight into a hot BRIGHT nickel solution.
With electroless the deposit is even all over and is neccesary to control the temperature and thus the deposition rate.This process we used to build up worn parts after grinding. The deposit can be controlled in microns. Electroless nickel has another advantage over chrome as it does not induce hydrogen embrittlemend in carbon steels. As in a previous post ,small solutions are hard to control and I found that the minumum pack sizes of ingredients only cater for the large users. some are very expensive.Solutions to function well need to be used regularly otherwise they can be problematical to restart.
With copper and nickel solutions I have managed with 30 Litres tanks.
You would also need high current rectifier. If I recall correctly copper needs at least 10 AMPS per Sq Ft
WJF