Stripping Nickel and Electroless Nickel Plating from Brass

A. Yes, there are a few proprietary products available that will strip EN from brass without many of the nasty chemicals often found in home brew recipes. What type of EN are you stripping? Low, mid or high phosphorous? Is it baked? Each of these variables will determine the proper chemistry. I would suggest contacting an EN chemical supplier.

A. Try a mixture of concentrated nitric and phosphoric acid. Alternatively there are a few solutions that are claimed to strip nickel from brass:
1) 18 g/l HCl + o-phenylamine - anodic dissolution at 35 ASF
2) 10% HCl
3) "Dekote A" 110 g/l + H2SO4 50 ml/l (Cannings)
4) 60-90% H2SO4 + 30 g/l Glycerine
5) 10% HCl + 5% H2O2; this may also go for the brass!

A. NaOH ; 60 g/l
ethylenediamine :120 g/l
MNBS (m-nitrobenzene sulfonic acid) : 60 g/l
TEMP : 170 °F
^-- ABOVE METAL FINISHING GUIDEBOOK 2001 --^

OR NaCN 60 G/L , MNBS : 80 G/L , NH4OH : SMALL TEMP : 140 °F

A. There are proprietary stripping processes available from suppliers such as Macdermid, Enthone etc (based on acidified MNBS (m-nitrobenzene sulfonic acid) with activators/inhibitors) which can do this job. Ask your local plater.

A. You can strip it electrolytically! Use 5% nickel sulphate or chloride solution and 4,5 V battery(cheapest); object=anode(+); cathode(-)= SS!

A. It is risky and has to be closely monitored because if you walk away and come back the next day you could be in for a world of hurt. In other words, the solution attacks nickel but also the underlying material as soon as it is exposed. You can buy proprietary Ni stripping solutions from your friendly neighborhood chemical supplier or you can use a combination of sulfuric, phosphoric and nitric acids. Try one first because you will probably need to do a lot of fine-tuning and could see pits and other problems that will make you want to change certain parameters.

A. Hi,

Satin nickel is electroplated. So, some parts will have more nickel than others. So, some are stripped easily and others...

To be made easily :
- 750 mL/L sulfuric acid 92%
- 3% vol. glycerin
- lead anode
- anodic, 10 to 20 Amps/dm2

If parts are greasy or handled, try to dip into an alkaline chemical degreaser before stripping.

Do not try to remove the complete plating. If plating resists on edges or corners, remove mechanically. Otherwise brass will be lightly eaten.

Before stripping production parts, some loose sheets freshly nickel plated shall be used to make older the stripper. Because, in the beginning, the reaction is not very quick.

Otherwise, try proprietary alkaline stripper from Enthone, Coventya, Atotech ... which are expensive but efficient and they don't eat polished brass.

Good luck

A. Use 250 ml/l hydrochloric acid anodically. The cathode can be carbon or copper. Add polyethylene glycol or glycerol to the bath. It has polishing effect. Add small amount of stannous sulfate. It coats on brass surface as a white coating to prevent further attack of the basis metal.

A. I would think the proprietary Ni strippers based on MNBS in 5% sulfuric acid with S activators would do the job.

A. Hi Scott. It is possible to remove the nickel plating from brass with proprietary strippers (see banner ad near the bottom of the page) or with generic chemicals -- but doing this safely and successfully may not be within the capability of the average inexperienced person (it's usually considered an industrial process). We don't know what facilities and expertise are available to you, and suggest that if you are not a professional plater, you might consider finding a plating jobshop to do this for you.

After removing the nickel plating you can probably buff the brass to an acceptable brightness and then lacquer it.

Regards,