Sciencemadness Discussion Board

searching for solution for immersion electroless nickel stripper

WFChem - 9-4-2024 at 03:27

Hi,

I have not access to the metalx nickel stripper from caswell. They dont ship to germany. Also nitric acid with concentrations higher than 3% are allowed.

Now I am searching for an immersion nickel stripper which strips the nickel without etching the base material. I found a stripper which contains sodium carbonate. But thats not the only one. A few ingredients more are needed because sodium carbonate alone does nickel not attack, but aluminium because of its alkalinity.

Does someone have an idea?

[Edited on 9-4-2024 by WFChem]

currawong - 9-4-2024 at 03:29

Do you know what the base metal is?

WFChem - 9-4-2024 at 03:36

Hi Sir,

the base material is aluminium.

Sulphuric acid with hydrogen peroxide does remove nickel plating but also pits aluminium. The part is not fully plated with nickel.

[Edited on 9-4-2024 by WFChem]

unionised - 9-4-2024 at 04:11

Might be worth trying to electrochemically remove the Ni in a bath of ammonia solution.
Ammonia will form a Ni complex but won't dissolve Al.

Failing that, sandpaper.

WFChem - 9-4-2024 at 04:13

Hi,

sandpaper, sand blasting is not possible. Its a hard nickel silicon carbide coating.

I am not chemist, but isnt it possible to add an ingredient to the hydrogen peroxide / sulphuric acid solution to protect the aluminium?

[Edited on 9-4-2024 by WFChem]

Sulaiman - 9-4-2024 at 15:28

I've been reading a little about fluorine compounds so I believe that hydrofluoric acid will passivate aluminium but not so much nickel, which could then be chemically dissolved - maybe.

The hazards involved make it unlikely to be a viable option unless very high value parts are involved.

I have no experience with fluorine or it's compounds and very little knowledge so do your own risk analysis ;)

Conc./Az. Nitric can also passivate aluminium but I've read that pitting would be greater than with HF.

WFChem - 10-4-2024 at 07:48

Quote: Originally posted by Sulaiman  
I've been reading a little about fluorine compounds so I believe that hydrofluoric acid will passivate aluminium but not so much nickel, which could then be chemically dissolved - maybe.

The hazards involved make it unlikely to be a viable option unless very high value parts are involved.

I have no experience with fluorine or it's compounds and very little knowledge so do your own risk analysis ;)

Conc./Az. Nitric can also passivate aluminium but I've read that pitting would be greater than with HF.


This is what I have also found out. I have used a cleaner for aluminium, nitric acid based. The nickel was stripped, but the aluminium faced also pitting. So its not correct that nitric acid dont attack aluminium?

Maybe in aluminium alloys other materials will be attacked.

[Edited on 10-4-2024 by WFChem]

WFChem - 13-5-2024 at 12:14

Does anyone know why in sodium carbonate based strippers Sodium 3-nitrobenzenesulfonate is present as oxidizer? Actually you can use hydrogen peroxide as oxidizer, nor? Glycine should prevent corrosion of base material.