-- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

on this site
current topics
topic 30121

Nickel Plating Repair

adv.   gold touch banner


Q. We are a manufacturer of parts used in the Aerospace industry. My situation is as follows: We have components, (silicon iron substrate), sent out for electroless nickel plating. During final assembly these plated components have a tendency to get damaged or chipped plating because of handling issues. These chips are extremely small, but big enough to expose the substrate material, hence corrosion. I need to repair these chips with brush plating since they cannot be submerged in a bath. I have been experimenting for several weeks now with brush plating and various nickel solutions. I cannot get my experimental parts to pass a salt bath. I have been experimenting with voltage settings, activating solutions, surface preparations with alcohol, plating time etc. I cannot blast the chipped areas either because they are assemblies.

Does anyone have any information or suggestions on what I can try to get this process to work. I am at a loss. I have contacted the companies where I purchased the equipment and have tried what they suggested. Can small chips be repaired with brush plating?

Thanks a lot.

Gary P [last name deleted for privacy by Editor]
Manufacturing Engineer (Aerospace Engineering) - Wallingford, Connecticut, USA


A. I see two different problems. The silicon present in the substrate requires Hydrofluoric acid not found in brush activators that must be safe for hand use (HF is so dangerous that will penetrate skin and destroy bone). The other is the EN itself, which is also very difficult to activate for it tends to develop a dark smut during reverse etch and will never present a grainy microstructure to provide anchorage. My opinion would be to strip the whole plating and do it again, probably using a more ductile plate such as a sulfamate nickel. It will pass a salt test and will not chip. Brush plating companies also offer other chemistries not based on sulfamates.

Guillermo Marrufo
Monterrey, NL, Mexico


Q. Guillermo,

I really appreciate your response, thank you. I need to find a solution that would allow me to replate the tiny chipped area without stripping the existing EN plating. The brush plating companies are telling me that their products will work, even though I have informed them of the silicon iron substrate. I've even sent them some experimental parts to repair. Is it even possible to repair these parts with brush plating and have them pass a salt fog or salt bath test. Since I do not have much experience in plating yet, I'm not sure I follow exactly what you are saying.


Gary P [returning]
- Connecticut

A. Gary,

To activate a EN deposit. First no pretreatment steps can be done with a anodic current. Then you use a acid with a anodic current will the EN deposit expose the phosphorus contents. To activate the EN is to use a cathodic current in 30-40 g/l Na Cn for 2 minutes. Rinse in 10 % chloride acid. Cathodic activation for 5-15 sec or to see if the gassing 3,5-4 volts in a clean 30 % sulfuric acid. Activate in a warm nickel activator. With brush nickel method is to use citric acid together with hydrofluoric acid. Remember never a anodic pretreatment.


anders sundman
Anders Sundman
3rd Generation in Plating
Consultant - Arvika, Sweden

January 26, 2016

Q. I have the exact same issue except my base metal is free machining steel, 12L14. I have small dings from fixturing down to base metal, plating is silver over nickel. It is a full up unit that is non hermetic so I cannot submerge it or subject it to cleaners or activators. I can put voltage on it however. Is there a way to top got the ding with any material to protect it from corrosion? It does not need to look pretty. Lastly, is zirconium an option?

Roman burtyk
Crane aerospace - Chandler Arizona usa

January 2016

A. Hi Roman. This can probably be brush plated, and there are specialty firms experienced in traveling to job sites and doing such repairs. I believe that zirconium is a non-plateable metal however.


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

January 27, 2016

A. I think the responses so far have missed two rather important points.

First, EN is not pure nickel. It is an alloy of nickel with (usually) phosphorus. "Repairing" it with "pure" nickel plating raises questions of corrosion sites, etc.

Secondly, and far more important, this appears to be for an aerospace application. Any remediation work must be signed off as acceptable by the client.

In my experience primes take a dim view of patched up work.

geoff smith
Geoff Smith

January 30, 2016

A. Geoff, Roman never mentioned that he was using EN. So brush plating Ni would be fine in this case.

Mark Baker
Process Engineering - Phoenix, Arizona USA

January 2016

thumbs up signI think we'll need to wait for Roman to clarify :-)
- "exact same issue" implies EN, but
- "silver over nickel" implies not EN
... and it's just not truly clear.


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

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site


Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.