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topic 1006

Non-cyanide Copper Plating

A discussion started in 1997 but continuing through 2018


Q. Hi, Does anyone have any experience with using EPI (Electrochemical Products Inc.) [a supporting advertiser] 30/30 non-cyanide copper solution to plate small, white metal (tin-lead alloys and zinc) castings in barrels or on racks?Thanks

Ken F [last name deleted for privacy by Editor]


A. I think that alkaline non cyanide copper operates only on steel and not on zinc castings.

sara michaeli
sara michaeli signature 
Sara Michaeli
chemical process supplier
Tel-Aviv, Israel


A. Ken, I'll have to disagree with the people who indiscriminately knock all non-cyanide copper processes. I have experience with the EPI (Electrochemical Products Inc.) [a supporting advertiser] E-Brite 20/20, the predecessor of the 30/30 bath. It did all the things the manufacturers claimed and then some - I successfully electroformed with it. The bath operates at a pH of (if memory serves) around 9.5, has great adhesion to steel, nickel, etc. you can plate out of it directly onto aluminum (naturally, no adhesion unless you zincate, but who cares when all you want is to electroform). I know people who use the 30/30 bath and are quite happy with it.

Hope this helps.

Wishing you luck, PlaterB

berl stein
berl sig
"PlaterB" Berl Stein
NiCoForm, Inc.
supporting advertiser
Rochester, New York



Q. Just out of curiosity, are you using an Acid Cu bath or are you using Cu Pyrophosphate? I know Cu Pyro has excellent throwing power but, I've only used it on WRe helicies. I'm not sure about SnPb or Zn.

I will do some research and see what I can come up with.

Laura Fatke


Q. Has anybody got information about alkali non-cyanide electroplating of zinc onto steel? We have tried the process unsuccessfully so far. Cleaning seems to be a critical factor in the process as the operational window for plating is far less tolerant than the cyanide based process.

Paul Hickey
plating shop

To minimize your searching efforts and to offer multiple viewpoints, we've combined some threads into the dialog you're viewing. Please forgive any resultant repetition or failures of chronological order.

Non-cyanide copper plating thickness limit


Q. What is the practical upper thickness limit for a functional copper plating on mild steel using a non-cyanide process?

Kirk Cooper
- Sidney, Ohio


A. Hi, Kirk. Copper electroforms have been built at least 1/4" thick. So the answer is that there is probably no practical upper thickness limit to copper plating. If you can phrase the question in terms of the details of your own situation maybe we can help further. Good luck!

Ted Mooney, Teds signature
Ted Mooney, P.E.
Pine Beach, New Jersey


A. Ted is correct. The question is so broad. When you say non-cyanide, you open the door to several chemistries (sulphate, pyrophosphate, fluoborate). Of those, the one most used to develop thick plates is the sulphate. A practical limit could be how much roughness can be tolerated on the outer surface. Without additives, which tend to increase stress and can lead to cracks, thus limiting thickness, 1/8" can be done with no more roughness than a piece of coarse emery paper. Beyond that, you can go up and end with something that resembles a coral or a sponge.

Guillermo Marrufo
Monterrey, NL, Mexico


Q. The key to my question is non-cyanide plating. For a commercial plater, plating a steel part which will be torch-brazed, what is the thickest copper plate you would feel comfortable putting on using a non-cyanide process?

Kirk Cooper [returning]
- Sidney, Ohio


A. Please tell us what you are trying to do, Kirk, rather than casting the question in the abstract where a dozen ifs ands and buts are needed :-)

Can you start with copper pyrophosphate then finish with bright acid copper? Can you buff mid-process to smooth it back up. Is it important to determine whether we can get to 3/8" vs. only 1/4" or would you be satisfied to reach 10% of that?

An often used approach is to nickel plate first, then you can directly plate a simple copper sulphate solution very very thick. Is a nickel strike objectionable in your application for any reason?

Is a cyanide strike is forbidden on ecological or safety principles? We don't know if the copper is supposed to be bright for decorative purpose, whether it needs to be a hard wear surface, survive a carburizing heat treatment, etc.

I guess I'm just saying that I'd prefer if your inquiry could start: "Here's what I am trying to do: ..." :-)

Good luck and thanks for your patience.

Ted Mooney,
Teds signature
Ted Mooney, P.E.
Pine Beach, New Jersey


Q. OK - I consider myself sufficiently chastised for lack of detail :-) Here's what I am trying to accomplish: copper plate a mild steel part which will later be brazed to another part. For environmental and process flexibility reasons, I desire to minimize or eliminate use of cyanide in the strike or the plating bath. Desired plating thickness ranges up to 0.002". Aesthetic function of the plating is secondary, but it should have a surface finish (Ra) not exceeding 0.0005". Brightness is not critical, but consistency of appearance is. Hardness should be similar to that of a cyanide-based process. Thank you.

Kirk Cooper [returning]
- Sidney, Ohio


A. Thanks, Kirk. Sorry, it wasn't my intention to make anyone feel hassled, just to offer the observation that the more detail provided, the more enthusiastic the readers usually are, and the more helpful they are usually able to be.

You may already realize that acid copper cannot be deposited directly onto steel surfaces because it will "immersion deposit" and offer virtually no adhesion (it won't survive brazing). If you can't use a cyanide strike, you would need to try either a pyrophosphate copper strike or a nickel strike.

Then you can finish with an acid copper (sulphate or fluoborate). I don't think .002" is a technological hurdle at all as, when I was involved in the stripping of the copper from the William Penn city hall tower in Philly, we discovered that they had plated copper at least 20 times that thick a hundred years ago.

It may be possible to directly plate .002" of a proprietary pyrophosphate copper in a single step, but I don't know enough about that to comment; you could inquire of a supplier of that process like EPI (Electrochemical Products Inc.) [a supporting advertiser] or zinex. Best of luck with it!

Ted Mooney,
Teds signature
Ted Mooney, P.E.
Pine Beach, New Jersey

Analysis of alkaline non-cyanide copper bath


Q. Dear all,

We are doing alkaline non-cyanide copper plating and would like to know the correct method to analysis the copper content by means of titration. Copper content in bath ranges from 8 - 12 g/L.

Can anybody suggest ?


Simon Li
Sky Chemicals Limited - Kwai Chung, NT, Hong Kong


A. Hello.


REAGENTS:Ammonium persulfate,concentrated ammonia solution,PAN-indicator(1-(2-pyridylazo)-2-naphthol,1 gr/l ethanol

PROCESS:Pipette 5 ml bath solution into a 250 ml Erlenmeyer beaker,add approx. 25 ml deionised water and 2-3 gr ammonium persulfate.Stir the solution for about 15 min.Add 5 ml of the concentrated ammonia solution;the colour turns to dark blue.Add another 50 ml deionised water and 4-6 drops of the indicator(dont add more.the changing of the colour will be worse)Titrate with 0,1 N E.D.T.A from dark blue to greenish-grey

CALCULATION:Consumption in ml * 1,27 Cu

By the way... How is your bath(performance)? And is it difficult to control? And have contamination problem? And can you plate zamac(zinc die castings)?

Could you answer these questions?

Good luck...

Emre Tuna
- Turkey

Non Cyanide Copper Plating of 14 ga Mild steel art work


Q. I visited a job shop that makes ornamental parts. You have seen them - the little garden animals and things like lizards and kokopelli's, etc. They currently use copper plating and then coat with a clear coat to preserve. I wonder if a non-cyanide process for plating 14 ga mild steel and then clear coating would work - do you see any problems? What other treatments can be applied to the plated parts to impart color changes such as darkening, aging and various antiquing finishes? Trying to stay environmental friendly from a simplicity in process and regulation perspective.

John Moritz
equipment sales - Vancouver, Washington, USA


A. The typical acid copper baths (copper sulphate or copper fluoborate) cannot be applied directly to steel because they won't adhere, for reasons more complicated that you probably are interested in hearing in the first round. There are proprietary copper pyrophosphate baths available from several suppliers; these are a bit more finicky than cyanide baths, and I can't guarantee they will discolor with heat in the same way, but they are worth investigating.

Another alternative is to nickel plate first, then acid copper plate. Again, whether this will discolor the same way as their cyanide copper would need to be determined.

Ted Mooney,
Teds signature
Ted Mooney, P.E.
Pine Beach, New Jersey

  gj nikolas banner


A. There are lacquers from companies like Agate that have some fantastic metal-like colors without the evils of plating. Check with them for the level of UV stabilization that the have/need. You might also acquire the book on patinas in the book section at this site. Not that bad priced and lots of pictures. Sort of a minimum library for an artist.

James Watts
- Navarre, Florida

January 11, 2013

Q. I am trying to electroplate mild steel with copper for an art project. I managed to get a little of the copper to plate but it seems that the dark "coating" on the steel prevents the copper from bonding easily and it just wipes off.

Is there a way to purchase sheets of steel, up to 16 x 20 inches, that does not have this "coating"? Is there a way, other than grinding, to get it off?

Lawrence Diggs
- Roslyn, South Dakota, USA

January 27, 2013

A. I think that when you say dark coating, you are referring to the mill scale on the steel. You can avoid this by buying cold rolled steel rather than hot rolled steel. Alternatively, you can remove the scale by sand blasting, grinding or with a solution of sodium bisulfide and water. You will find this acid salt sold as a pool additive (lowers pH).

Justin Kumph
- Philadelphia, Pennsylvania

May 8, 2018

Q. I am trying to plate alkaline non cyanide followed by Acid copper and bright Nickel.
But after heating at 130 °C for 30 min. it is getting blisters at LCD areas.
What may be the probable cause as in alkaline cu the thickness is 10 to 15 micron?


Akhilesh yadav
Electroplater - Ludhiana, Punjab, India

May 9, 2018

A. Hi Akhilesh,

Please clarify if blistering happens between base substrate and alkaline non cyanide Cu or alkaline non cyanide Cu and acid Cu or acid Cu and bright Ni deposit.

Possible cause could be improper activation of base substrate prior electroplating or Cu oxidation prior following plating or poor Ni deposit ductility.


David Shiu
David Shiu
- Singapore

May 10, 2018

Q. Hi Shiu,
It is from base to alkaline copper layer.
The substrate is Zinc Diecast and the activation is 2% HF solution for 20 seconds.
The blister is coming only after heating the substrate up to 130 °C.


Akhilesh Yadav [returning]
Electroplater - Ludhiana,Punjab,India

May 11, 2018

A. Hi Akhilesh,

You may prolong zinc die-cast activation (or even with electrolytic activation) or plate cyanide Cu strike to improve adhesion.

Also, you may remove organic or metallic impurities from alkaline non cyanide Cu bath to minimize blistering at LCD area upon baking.


David Shiu
David Shiu
- Singapore

May 12, 2018

thumbs up sign Thanks,Shiu.

Akhilesh Yadav [returning]
- Ludhiana,Punjab,India

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