Adhesion of Nickel plate onto Stainless Steel
Q. We need to apply Bright Nickel plus Chrome over SUS 304 Stainless Steel. Is a conventional Wood's Nickel strike a foolproof process to obtain the necessary adhesion to Stainless Steel? We need to apply 5 microns of Nickel and 0.25 microns of Chrome plate.
What process will provide excellent adhesion ? Please give a complete cycle.
Thank you in advance for any help provided.Enrique Segovia
Guadalajara, Jalisco, Mexico
A. Hi Enrique. Wood's Nickel would be my first choice, but there is no such thing as a foolproof process.
The cycle could be soak clean, electroclean, acid dip, Wood's nickel (you may or may not want to start with reverse current), Watt's bright nickel, chrome plate, with rinses in between. But I don't like to claim that this is a 'complete cycle' because there are many other possible steps, there is no guarantee that this process will work for you, and there is a wealth of background information that you should have which I am not sure whether you have or not.
5 microns of nickel is only for a very mild service condition. Best of luck.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
A. ASTM B254 [link by ed. to spec at TechStreet] entitled "Practice for Preparation of and Electroplating on Stainless Steel" should provide all the answers to this question. There are many options to use for this procedure but I can't say that any are "fool-proof" as some fool will always prove me wrong. The ASTM spec can be ordered from ASTM at www.astm.org.Lou Gianelos
- Mentor, Ohio
A. I agree with Ted, there is no "foolproof" process for plating on stainless steel. Here at Oneida we routinely plate nickel over many different stainless alloys, and Wood's nickel activation is our activator of choice.George Brackett II
silversmiths - Sherrill, New York
A. Degreasing (solvent, soap, electro)
Acid dipping (HCl 20%)
Electro-pickling (etching) cathode of Pb plate
5 Volt 30 sec room temperature
Wood's nickel strike
Wanted platingKim Kyuong Min
- suwon, South Korea
A. I routinely electroplate bottom area of stainless pots with 450 microns copper. The pots are used over direct flame. For this application I use 2 min anodic and 6 min cathodic cycle in Wood's Nickel, as recommended A.K. Graham's handbook. The results are excellent.Yashawant Deval
utensils - Pune, INDIA
A. We plate silver onto a variety of stainless steels, including 304, 316 and 431, and find that the most successful method of activation is achieved using a proprietary product called Actane L-59 from Enthone-OMI. I don't know if it has a different name in the US. I think it's main ingredient is sulfuric, but I'm not sure what else is in it.
Our procedure is:
- 25% NaOH 90 °C (no electroclean)
- Actane L-59 anodic 3 minutes, cathodic 2 minutes, 1 ASD
- Wood's Nickel Strike
- Silver Plate
Of course the last two steps would depend on your final finish.John Reid
plating shop - Brisbane, Qld, Australia
Ed. note: Thanks, John.
Readers: let's leave it that proprietary electro-acids before the Wood's strike may be effective, rather than trying to compare different brands of proprietary electro-acids :-)
November 21, 2013
I need help with electroplating gold onto stainless (18/0).
I am using a 4.5 V, 300 mA power supply and dip plating flatware. My anode is currently a carbon graphite anode about .25" x .25" x 3" in length and I am dip plating in baby food jars (pretty crude setup - but I would think it should work)
I am having trouble with adhesion, I have read the threads on finishing.com and it seems pretty straight forward, but I keep getting poor results.
My processes have been:
1- electroclean with alkaline solution - 30 sec to 1 min (I tried both anode and cathode- not sure what the difference is in terms of cleaning - one is more gassy)
2- "stainless activator for gold" from a hobby plating supplier -- I assume this is like a Wood's strike -- 20-30 sec.
3- gold plate for 20-30 sec.
1- 'degrease' or clean with various products (soap, simple green, etc.)
2-ultrasonic clean for 3 min in heated soap/water solution)
3- electro clean in alkaline - 30 seconds
4- "stainless activator for gold" for 20 seconds
5- gold plate for 20-30 sec
I assume that since my problem is with adhesion, I am not properly cleaning the surface of the stainless -- but then again 1 minute in electroclean should do the trick, shouldn't it? I am also trying the water break test with distilled water. I've noticed that sometimes the water break test isn't sheeting and the adhesion is very good after I plate, so I don't get that either.
It seems like there are a lot of variables in plating gold onto stainless, and I might have to keep trying different things ... but its proving to be costly in both time and money. Any help would be great!
Oh and I wanted to try the recipe from poster Kim Kyuong Min, but I don't see his voltage and times - and is HCl hydrochloric acid? And what is electro pickling and is it necessary?:
Bringing this to a shop is not an option as I am doing some tricky masking and shops (at least the ones I've talked to) generally charge way way way too much to plate anyway. I need to set up a small plating station with reliable (and hopefully quick) results.
Thanks in advance
- Lambertville, New Jersey USA
A. Hi Ryan. Plating shops may charge more than you want to pay or can afford to pay; but as they struggle to remain in business, I hope they can bite their tongues in response to your "charge way way way too much to plate" comment :-)
But on to the technical stuff ...
a). If you have any doubt whether the flatware is clean enough, just scrub it with a stiff toothbrush and powdered Pumice [linked by editor to product info at Amazon] before electrocleaning, rather than experimenting with "various products", ultrasonics, etc. It's faster, easier, and better for tiny onesy-twosy work.
b). I don't think you should go directly from the electroclean to Wood's Nickel, but should have an HCl dip in between (plus rinsing between each step, of course).
c). Getting good gold adhesion is easier than getting good adhesion for other metals because gold is relatively soft and weak, and "perfect adhesion" is only 22,000 psi whereas other metals may require 3 to 4 times as much adhesion. 108 A/m^2 is sufficient current for this case. Further inferring from Dini's "Electrodeposition" =>
an electro acid is not necessary when the subsequent plating is gold, just the Wood's Nickel strike looks sufficient (of course, inferences are subject to error since there are many stainless alloys, etc.)
d). Yes, HCl is hydrochloric acid, but Kim is unlikely to see your posting since his was from long ago. Good luck.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
November 25, 2013
Q. Hi Ted -
Thanks for the guidance ... much appreciated.
And yes perhaps I shouldn't judge a business I know nothing about ... but over 100 USD to plate 6 forks blew my mind at the time.
In response to your suggestions, I have some further questions if anyone can weigh in...
1- For the HCl - Can I use a muriatic acid instead? That is more readily available than HCl.
2- And If I did have to clean flatware in bulk before plating (20 pcs at a time) is there a bath or some other way to clean other than a toothbrush with pumice?
Thanks again for the help.
Oh and one more question: 3- How do I read 108 A/m^2? -- what does that translate into voltage and amps?
- Lambertville, New Jersey, USA
November 26, 2013
A. Hi again. My plumber charges $100 an hour, and no way can a plating shop take your 6 spoons from start to finish in less than an hour. My Jeep dealer charges non-refundable $125 to put it on a lift so they can tell me how much they'll charge to fix it. My roofer wants $200 to look at the roof to tell me what's involved in fixing the leak, although he had promised a warranty. How much did the plating shop charge you to look at your forks? Time is money, and plating shops are in the same situation as plumbers, roofers, and mechanics. Remember that no employee at most plating shops can touch the chemicals you plan to use unless s/he is receiving annual haz-mat training, so I hope you are at least wearing goggles [linked by editor to product info at Amazon] and protective gloves [linked by editor to product info at Amazon] if you're doing this.
1). Muriatic Acid [linked by editor to product info at Amazon] is commercial HCl, so yes.
2). The methods you described are fine, just not as easy and reliable. Take one day at a time and successfully plate one single fork using safe and easy pumice before you worry about doing 20 at a time with chemicals.
3). 108 A^m2 means 108 Amps per square meter of surface area being plated, i.e., 0.07 Amps per square inch. Good luck.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
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