SAM4CH - 2-8-2006 at 14:26
What is the best bath "solution" of nickel electroplating on cast steel, and what about using Nickel-Chromium Alloy Resistance Wire (80% Ni, 20%Cr) as
anodes and source to prepare nickel salts to be used in the bath!!
12AX7 - 2-8-2006 at 14:41
Hum, might work I suppose. You'll have to keep the chrome in solution somehow, possibly excess acid might do it. I doubt that'll make a real great
deposit in any case.
Easy enough to dissolve the wire in say, HCl, with H2O2 to get the rather unreactive nickel going, crystallize the salt (NiCl2.6H2O or so?), CrCl3
should remain in solution with some NiCl2 for some yield (probably around 80%) of crystallized NiCl2. You can also dissolve stainless steel, though
the main product is FeCl2, and nickel is present to, at most, 10%.
Once you get the raw nickel salt, you might be able to use an electroless method. I think this involves strong reducing agents such as phosphites or
hypophosphites, which are rather hard to make without phosphorous AFAIK. Otherwise, you can precipitate the metal, either with a reducing metal like
zinc powder, or by precipitating the hydroxide and reducing that with hydrogen or carbon, then melting the material into anodes (mind the melting
point is near steel's).
And that's just to get a crummy deposit. Lord knows what kind of levelers and brighteners and complexes you need to get a worthwhile deposit.
Tim
IrC - 2-8-2006 at 16:37
The biggest problem is pretreating. You need to have your work cleaner than anything you have ever cleaned before to properly electroplate nickel on
to steel. Degreasing/rinsing/acid bathing/rinsing, and then very quickly moving the work into the plating tank using tongs that are equally clean.
Also, some people are severely allergic to nickel and you might be one of them so do not forget to consider that. Nickel with a slight phosphorus
impurity really helps here in making a quality plate. Here is a very simple formula that works extremely well. Formula to be added to 2 US Gallon
Distilled Water: Nickel Sulfate 1700 gms Nickel chloride 300 gms Boric Acid 200 gms operate at 1 amp per 10-15 sq " of surface area, voltage @ approx
1.5 - 4 volts. You want a basket with pieces of nickel connected as an anode, and as mentioned they make nice chunks of phosphorus nickel anodes, one
guy on ebay sells them cheap (I bought 20 pounds of them). Here is an idea of Electroless plating:
http://en.wikipedia.org/wiki/Electroless_nickel_plating
Many companies make solutions for this.
[Edited on 3-8-2006 by IrC]
Twospoons - 2-8-2006 at 19:51
Do you know if the same bath will work for plating onto brass or copper?
I thought NiCd or NiMH batteries would be a better Ni source than nichrome wire.
IrC - 2-8-2006 at 23:24
I would say it should work, easy enough to try and see. I do not think nichrome is a good choice, as stated the only impurity you want in the nickel
metal is phosphorus. Not being a guru on the subject I would not reject the possibility that NiCr would work, I would try it as nothing ventured
nothing gained. I think the source ideas you had sound better than NiCr though. Making a nice finish is so damn hard in the first place why not invest
in some proper sources.
The ebay guy I mentioned seems to have vanished, good thing I bought 20 LB while I could. Here are some interesting links:
http://cgi.ebay.com/Nickel-Plating-Electroplating-Plug-N-Pla...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=25001...
http://cgi.ebay.com/Nickel-Chloride-Nickleous-Laboratory-Che...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=30001...