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Can sulfuric acid be used to remove nickel plating from aluminum?

Metalx nickel stripper

⇦ (tip: readers rarely show much interest in abstract questions, but people's actual situations usually prompt responses)   smiley face

Q. Okay, so if you are acid etching a nickel sulfamate surface that's flat not shiny, and in some areas runs black how do you correct the blackened nickel area?

Drew soto
Employee - California
October 25, 2022

⇩ Closely related postings, oldest first ⇩

Q. Hi,
I am an engineering student from Malaysia. I am conducting a research on: can sulfuric acid be use in etching to remove a nickel plated aluminum disk? I would like to remove the nickel but not the aluminum from the disk.
1. what is the concentration of the sulfuric acid for etching? ( is it 30% )
2. do I need to mix the acid with water?
3. is the method the same as anode and cathode?
4. how to calculate the time for the etching process?
5. what is the suitable container to use for etching?

Can anyone give the procedure or idea to conduct the experiment above?

Hope to get some help..
Thanks in advance.

Lee Chee Hun
student - Malaysia

A. Nickel can be stripped from aluminium using the Laybere solution; this a mixture of 3 parts of conc. sulphuric acid to 2 parts of water. It is used at room temperature with an applied anodic current of about 40 A/ft2. Your container will depend on the size of your parts, but I see nothing wrong with a glass beaker [adv: beakers on eBay or Amazon] if it is of the correct size. If you need something bigger, use a PVC, polypropylene or rubber lined steel tank. As far as the processing time is concerned - it all depends on how much nickel you have to remove and what the temperature is. Now that you have been told what to do for your project, go and do some experiments for yourself, but don't forget to give due reference to the sources of your information as it would be most unethical to claim the credit yourself.....

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

A. I doubt if it will work. It will also depend on what the aluminum alloy is.
Look at concentrated nitric acid. One notch below red fuming. Regular nitric that most people would use commercially has too much water in it. The part has to be absolutely dry when you put it into the acid. Note that it will slowly absorb water from the air and you will at some point have etched parts.

James Watts
- Navarre, Florida

"Sulfuric acid Manufacture"

on AbeBooks

or Amazon

(affil links)

Q. Hi,

please do help me out with my experiment, as the deadline is next week. I have no idea whether sulfuric acid can be used to etch (remove) the nickel plated aluminum disk. I only want to remove the nickel not aluminum. Currently, I am using aluminum potassium sulphate to etch (remove) the nickel.

Thank you Trevor Crichton & James Watts.

Dear Trevor Crichton,
I will definitely acknowledge the ideas given by you in my project. will sulfuric acid perform better that aluminium potassium sulphate to etch the nickel plated aluminium disk?the area that I would like to remove is about 1 cm x 1 cm only. I can use the Laybere solution as a guideline?

Mr James Watts,
Based on your response, do you mean that sulfuric acid will not be able to etch (remove) the nickel plated aluminium disk? And nitric acid will be a better solution?
'One notch below red fuming' I don't understand this statement -- can you explain further.

hope to hear from both of you soon.thanks,

Lee Chee Hun [returning]
student - Malaysia

simultaneous replies

A. Laybere solution has been well known for many years, so there is no reason why it can't be used as a benchmark. I think you will find the sulphuric acid bath will react faster than aluminium potassium sulphate. Be careful of the sulphuric acid as it is very corrosive.

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

A. My company regularly uses a 50% (vol) solution of Nitric acid, and DI water to remove nickel from aluminum. This solution will hardly attack the Aluminum substrate, and works quite well.

Marc Green
Marc Green
anodizer - Boise, Idaho

A. OK, my head was somewhere other than firmly attached to the neck. The procedure that I talked about was for removing EN from steel. My bad.

In another letter, an author talked about using 12% sulfuric acid with peroxide for removal of EN. Do not remember the substrate.

James Watts
- Navarre, Florida

A. James, the sulphuric acid/peroxide mix is pretty potent and will take off most metals - I have used a similar formulation for dissolving both nickel and copper, but it will chew up any metal substrates if you're not careful!

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

"Sulfuric Acid Use and Handling"

on AbeBooks

or Amazon

(affil links)

Q. Hi,

thanks so much for the positive responses.

As the deadline had been extended, I hope to try out the two experiments using sulphuric acid and nitric acid.

I am trying to source for an ampere meter. (Do I need it?)
This is how I plan to conduct the experiment:
1. I will conduct it in a fume cupboard.
2. pour 150 mL of H2SO4 to 100 mL of DI water in a beaker.
3. after mixing it, will place a dummy disk in the beaker.
4. the Al disk ( 95 mm diameter ) will be placed inside the beaker.
5. the current is about 9 V. Anode will be clip to the Al disk, while Cathode will be connected to the dummy disk.
6. etching time still unknown... (can it be calculated/ measured?)

Please do correct me if my procedure is wrong.
How will the ampere meter come to good use? how will it function?
Any other better suggestions?

Thanking all of you in advance.

Lee Chee Hun [returning]
student - Malaysia

Ed. note: Ampere-hour meters are available from all suppliers of plating rectifiers and power supplies.

Q. Hi,

Any suggestions / ideas regarding to the procedure that I am going to use? is the method correct? as I hope it is safe to conduct it.

Please let me know, thanks again.

Lee Chee Hun [returning]
student - Malaysia

A. You can use electrolytic etching -- this process is much safer than H2SO4. Slightly acidified nickel sulphate solution can be used as electrolyte, object=anode, platinized titanium or stainless steel=cathode.

Good luck!

Goran Budija
- Cerovski vrh Croatia

A. You will need an ammeter to tell you the amount of current being passed. You will also need an accurate clock to tell you the time spent; I suggest a stopwatch. Your process looks basically sound, but I suggest you check with your supervisor before doing it - he knows your abilities and the abilities of your classmates and the equipment. Furthermore, he is responsible for you!

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

Q. Hi,

Thanks, I had tried out the experiment with sulphuric acid, it's a bit dangerous as sulphur gas was released during the etching process. Will nitric acid be the same as well?
Additionally, I would like to add a system (timer) that can cut off the current once the etching process is finished.
Can it be done? with this, I will try out on different surface size to etch, so I can set approximately the time needed to stop the current once the process is finished.
But I am concern that the aluminum potassium sulphate which I am currently still using will degrade after 2 rounds of etching. the time set for the 1st round should be faster compared to the 2nd round,right? will it be the same as well for sulphuric acid?

thanks again for replying.

Lee Chee Hun [returning]
student - Malaysia

A. Hi, cousin Lee.

The dangerous part is conducting experiments except under a lab hood, or without wearing the correct PPE experiment, or without proper training and/or supervision. The dangerous part is asking someone on the internet, who you don't know and who doesn't know you or your facility or your training level, about the safety of a proposed experiment. As Mr. Crichton noted, your supervisor is the one who must be asked these questions and who must supervise you during it. Good luck, and stay safe.

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. If you want to remove the nickel from hard drive disks you cut the disks up into 1/4 inch strips and soak it in HCl or muriatic acid this will dissolve all the aluminum base metal and all you are left with is the nickel platinum cobalt alloy thin film. I do this all the time and sell the foil on eBay as a platinum alloy. there is a fast reaction at first it takes about a week for me to dissolve 60 disks at once I hope this helps.

William Thompson
- Watson, Sask, Canada

A. You could use household bleach [adv: bleach/sodium hypochlorite in bulk on eBay or Amazon] , it works on the disk.

theodorus schuurbiers
- Curacao Island, Caribbean

thumbs up sign Thanks William and Theodorus. You folks are talking about scrapping, but in this case Lee is looking to remove the nickel coating without attacking or doing any damage to his aluminum disk.

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

Q. Hello all,

I am a Belgian collector of antique guns and currently trying to remove an old damaged nickel plating (could be nickel/chrome) from a steel gun frame.
I tried electrolysis with a solution of about 30% Sulfuric acid (I use battery acid [affil link]) and distilled water. Temperature about 20 °C, current is supplied by a car battery charger [on eBay or Amazon affil link] .

Well, it doesn't work at all. The acid attacks the steel and destroys my anode, but it has no effect at all on the nickel plating.
The gun is a Colt 1849 Pocket made in the late 1850's but I doubt the plating is original factory work.
I usually remove rust from steel parts using a solution of about 30% Chlorhydric acid and water in the very same home-made electrolysis installation. The solution removes all the rust and does not affect the steel in any way.
Yet chlorhydric acid doesn't work on nickel plating either.

A US correspondent told me about a good and effective chemical produced by Brownells [affil link], but it seems like that company is not allowed to export the product.
So if anyone can provide a better solution, I'll be very pleased to read about it.

Thanks in advance,

Marcel Cansse
- Knokke, Belgium
November 3, 2008

A. Hi all..

If you got NiCr to be strip..

you shall remove the Cr with sodium carbonate / washing soda [affil link] anodic at 3 ADM...after that, only you strip the nickel by sulphuric 60%...

To strip nickel from Aluminium disk, you need 70% dilution from 68% nitric acid by dipping process..the nickel will be remove..the fume might be a bit danger so be careful.. to create process inhibition you may add Sulphuric acid at 5% dilution.. but the more you put it will slow the process..

Monggo luton
- Selangor, Malaysia
November 12, 2009

A. Re colt nickel stripping, I have used the Brownells [affil link] solution before on a 1970s Colt Combat Commander and it took the nickel off great but didn't touch the copper under it. A 99 cent bottle of ammonia [on eBay or Amazon affil links] took care of the copper.
I am now working on refinishing a 1914 Luger that had been nickeled and I was told the Brownell's solution won't work for that because it only works on electroless nickel.
I am now trying a solution of sulfuric acid and ammonia.
I will try and follow up with results.

Tommy Kunkel
combat firearms - Bremerton Washington
July 14, 2011

A. Hi, Tommy.

I am very surprised that a solution which can strip electroless nickel is unable to strip electrolytic nickel plating. If you were successful with it last time, I'd try again before assuming it won't work. The Metalx solution will, of course, work. Good luck.


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. I have successfully stripped nickel from automotive parts which were zinc die cast in a sulfuric acid bath at full strength with an addition of GLYCERINE to minimize base metal attack. The parts to be stripped are anodic and lead anodes are used. For aluminum I suggest 50% Nitric Acid solution. Proper PPE and good house keeping measures are always important. Good luck.

Eric Bogner
- Toronto Ontario Canada
July 25, 2011

Q. Hi, I am also an engineering student from Malaysia. Currently I'm doing research on how to remove nickel from FCC Catalyst. For now, I only get 63% removal by using 10M sulphuric acid with 30 °C in 120 RPM shaker.

1) Can anyone suggest how I can increase the percentage removal?
2) What is the interaction between nickel and sulphuric acid?

Thank you.

Nur Fadhilah bt Abdul Rahman
Malaysian Student - Kuala Lumpur, Malaysia
May 12, 2013

Q. You say to use 3 parts Conc. Sulfuric acid to 2 parts water ,
At what Mol weight or % Sulfuric acid is considered concentrated?

Terry Way
hobbyist - Winder, Georgia - USA
January 7, 2022

A. Hi Terry. Trevor's postings were from 17 years ago so I don't know if he'll see yours and follow up, but in this context "concentrated" means 'as concentrated as possible/practical', i.e., 98% / S.G. 1.84 / Molarity 18.4.
Some people might say concentrated sulfuric acid is only 96% for some practical reasons, but when you're diluting with water that way, whether the acid was theoretically 98% or 96% really doesn't actually matter. Good luck!
I hope you and other readers are attentive to the safety warnings he repeats 3 times in the course of the discussion.

Luck & Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey
January 2022

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