Ted Mooney, P.E. RET
- Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
-----
Need to do Zinc Plating on Stainless Steel
Tip: Readers want to learn from their effort, often replying only to postings with your actual situation.
Q. My question is, how is it possible to apply zinc coating on Stainless steel? Please suggest or give us some documented reference if available.
wasim akram- Noida, Utttar Pradesh, India
November 23, 2021
A. Hi Wasim. As already noted on this page, getting zinc electroplating to adhere directly on stainless steel is unlikely because plating must be done onto raw metal and stainless steel almost instantly forms an oxide finish rather than leaving raw metal exposed. As described, the usual resolution to this issue is to do a Wood's Nickel Strike first ... this is a highly acidic solution which dissolves those oxides, and a dilute plating solution which simultaneously applies a thin nickel layer as the oxides are dissolved. After the nickel strike, you are plating onto nickel rather than onto stainless, so a number of different metals, including zinc, can be plated onto it. But it is difficult to go much further in the abstract -- please tell us the situation you have in mind.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
November 2021
⇩ Related postings, oldest first ⇩
Q. I am confused by my part supplier that Stainless Steel parts can't be coated with Blue Zinc. So he is giving my parts coated with Nickel. I need this part to be electrically conductive in addition to having a bright, nice finish. Please advise if SUS 304 can be coated with blue zinc, which would be contrary to what I am told. What Stainless Steel grade would you recommend to get the part conductive and look great at the same time? Thanks
Koe KGParts - Singapore
2004
A. Although I can't think of an example of an item that is blue zinc plated on stainless steel, I know of no reason to think it is impossible or even particularly challenging on a technical basis. But plating onto stainless steel usually must start with a nickel strike to activate the surface anyway. The work would then need to go very quickly from this nickel strike tank to a zinc plating tank, and it may be logistically impractical on a production basis for many plating shops to quickly go from the nickel strike tank to the zinc plating tank if they are not set up for it.
Nickel is considered a decorative finish, more so than blue zinc, but is far better for conductivity as well. Zinc is never used for electrical conductivity because its corrosion products are sticky, voluminous, and non-conductive. The ideal decorative and conductive finish is gold plating, but that may be too expensive for the part in question, about which we'd like to hear more. Thanks!
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004
Q. Thanks for your reply. The part is a spring type component used to conduct current from a battery. I have the part on hand now and the finish is quite dull with the nickel plating on. You mentioned that nickel is a good choice for finishing. Do you think that I might have been fleeced? As in the part was never plated? I'll like to achieve a chrome like finish on these parts.
Koe KG [returning]- Singapore
2004
A. I can't comment on whether you may have been fleeced based on your assessment that the finish is "quite dull" -- maybe the plater was trying to satisfy you with a dull nickel finish. But I can say that it doesn't need to be dull, and usually isn't in situations like this. The nickel plating can be quite bright.
But your plater is doing you a favor providing nickel plating rather than zinc plating :-)
It is very widely used for applications like this. Look at the charging contacts of your cordless phones, radios, DC adaptors, etc. ... these are often nickel plated, and certainly never zinc plated. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2004
Q. We have been seeing sporadic "failures" of clear zinc plating. Specifically, on PEM inserts (PEM P# F-032-1). The PEMs are 300 series stainless steel and inserted into a Cold Rolled Steel (CRS) panel. The zinc on the CRS portion is very consistent but the zinc on the PEM exhibits a "bubbled" look and appears to have voids where no zinc has affixed to the PEM. Is this normal for stainless steel to basically reject adhesion by zinc?
JP SmithBuyer - Portland, OR, USA
October 22, 2009
A. Plating on 300 SS requires proper cleaning and acid activation followed by a Wood's nickel strike and then zinc plated. (requires appropriate rinses)
James Watts- Navarre, Florida
October 26, 2009
October 2020
A. Hi JP. I'm not seeing why you should install stainless PEMs then have to nickel strike them in preparation for zinc plating when it seems you could just use steel PEMs and zinc plate the whole thing.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Usually we don't go for plating on Stainless steel parts, but it is not like that it cannot be done, is it? Any concept?
Somya Kumar- India
February 7, 2011
A. Hi Somya. You need to start with a nickel strike process, then it can be done. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Q. Parts with combination of mild steel and stainless steel have to be plated with non-cyanide alkaline zinc and baked at 200 ° C for 4 hours. How to achieve perfect adhesion after completion of this process? Now there are blister issues. Undercoating with Wood's Nickel is given. Please suggest a suitable process sequence.
RAVI KUMARARTEK - CHENNAI TAMILANDU INDIA
January 31, 2014
A. Hi Ravi,
To achieve good adhesion, steel parts shall be electro-activated by sodium hydrogensulphate/sodium bifluoride mixture follow by Wood's Nickel strike prior plating.
Regards,
David
David Shiu
- Singapore
February 2, 2014
February 20, 2014
A. Dear Ravi,
Please try the following process sequence.
1) Degreasing
2) Electrocleaning
3) Rinse
4) HCl Acid Activation
5) Woods Nickel strike
6) Rinse
Hope it will resolve your problem.
Note:
Please ensure where you are getting peel off problem, whether in Zinc Layer or Nickel Layer.
Thanking You,
- Bangalore, Karnataka, India
Galvanic Corrosion. Can I galvanize 304 Stainless to Prevent?
October 22, 2020Q. Hello all,
We have a product which requires a good EMC earth. Our prototypes have used Be-Cu spring touching our Aluminium/Zinc coated steel chassis. Our product is a Dishwasher and we discovered quickly in our humid (and occasionally wet) environment we had set up a galvanic cell which resulted in rapid corrosion.
Given the requirement of good electrical contact, acting as a spring and the high humidity, we felt that changing the material from Be-Cu to Zinc coated steel would be the best option, but our spring supplier is unable to source a suitable material.
They are proposing 304SS, but I still have concerns that we will have a different galvanic potential and therefore corrosion issues. They are saying we could put a zinc coating on the 304SS, but I'm not sure if this would be a good option or not.
It seems you 'can' coat stainless, but I'm not sure if it would be the right thing to do! We need to finalise our material decision pretty quickly as we are already behind schedule on tooling.
Any comments or suggestions welcomed.
Thanks,
Danny
- Dunedin New Zealand
A. Hi Danny. If the primary problem is galvanic corrosion, you can simply zinc plate the Be-Cu spring. A second approach would be to zinc plate a music wire spring, or you could try the uncoated stainless spring the supplier is suggesting; the galvanic corrosion should be greatly reduced compared to copper. But yes, you can zinc plate stainless steel after Wood's nickel striking it if that is the resolution ... but zinc is a poor contact material.
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 2020
Q. What happens to stainless spring if attached to part while it's zinc plated?
I have a steel weldment that is being zinc plated. In this weldment there is a spring. Looking to have the spring be a 304SS material. My question is what will happen to the spring when it gets plated? Not looking for the spring to be plated just trying to figure out if there will be any effects of having the spring in there during plating.
Eric Stoddart- Brighton Michigan
October 29, 2020
A. Hi Eric. I don't think the plating process will actually hurt the spring, but non-adherent zinc plating will probably plate out onto it as ealier contributors noted,
Luck & Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
----
Ed. note: For additional situations, options, and opinions please see also:
• Thread 48652, "Plating zinc onto stainless steel?"
• Thread 32579, "Black zinc chromate plated on stainless steel"
Q, A, or Comment on THIS thread -or- Start a NEW Thread