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Acid-based electroless nickel stripper?

2000

I am a plating engineer for a plating company in the Minneapolis area. I am working on a project that requires stripping approx. .0002 of electroless nickel from substrates that are attacked by high PH electroless nickel strippers. I am looking for a "acid" based electroless nickel stripper. the substrate stripping off of is a thin copper plate. I cannot attack the base metal to any degree.

The top plate is sensitive to the normal electroless nickel strippers on the market and is the reason a acid mixture must be used. Any one aware of products available to help me with my project. Your assistance would be so greatly appreciated.

Thank you.

Todd Huehn
- Blaine, Minnesota

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Hi Todd, This is only a suggestion: I remember that, when I worked in iron coppering and chroming, we used Hydrochloric acid to remove Chromium layer (better if densified with a lot Zinc chloride, in order to slow down the attack). Maybe this solution is enough for your purpose. Let me know how your attempt goes on. Otherwise another metal will be required to be converted to base metal on Nickel. I hope all this works and good luck.

Francesco Cicchetti
- Sulmona, Italy
2000

Todd, You make us guess what the base material is. My guess is Aluminum. You can strip EN off of iron or aluminum with pure nitric acid. Not red fuming, but not the normal slightly watered down version that most people by from their vendor.

The part must be absolutely dry! You must move to the rinse tank rapidly after you clear the top of the tank. You can not dawdle as you put the part in the rinse tank. It takes very little water to get into the acid such as setting out open in florida for a couple of days to have it ruin parts.

For safer products, contact Metalx (Ronatec.us) [a finishing.com supporting advertiser] for nickel strippers from nearly any common substrate.

James Watts
- Navarre, Florida
2000

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Todd, you're looking to strip EN from copper, correct? If so, a solution of NBSA (nitrobenzene sulfonic acid) and sulfuric acid may work for you. The process is documented in the chapter entitled "Stripping Metallic Coatings" in the Metal Finishing Guidebook..

Megan Pellenz
- Syracuse, New York
2000

Todd, My pardons for my inability to read the whole paragraph. Metalx (Ronatec.us) [a finishing.com supporting advertiser] is still the way to go for EN off of copper. Megan, thanks for correcting my boo-boo. Jim

James Watts
- Navarre, Florida
2000

Megan, The EN stripper noted in the Metal Finishing Guidebook and Directory 2000 is actually alkaline-based with NBSA, NaOH and ethylenediamine.

Charles Rosenstein
- Holon, Israel
2000

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Well, if Charles says that the article mentioned in the Metal Finishing is an alkaline one, he should know it as he is the one that wrote this article :-)

Sara Michaeli
Tel-Aviv-Yafo, Israel
2000

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I've used the strip Charles refers to and since the operating pH is about 12, it will not fit Todd's application. I've also used some of the strips listed in the Guidebook under Nickel strips to strip EN. That's where "may work for you" comes in Charles. Just offering a suggestion. No offense meant Mr. Watts, I enjoy reading your many informed responses. Megan

Megan Pellenz
- Syracuse, New York
2000

Megan, no offense taken. It was an honest thanks.

James Watts
- Navarre, Florida
2000

the actual substrate is copper. But in this case it's circuit board work with photo resists. solder masks and so on. Todd Huehn

Todd Huehn
- Blaine, Minnesota
2000

You might want to try a 50-50 mixture of nitric and hydrochloric acids. It won't appreciably etch copper.

Phil Pace
- Tulsa, Oklahoma
2000

Hi Todd, Nitric & Acetic 7:3 ratio with 10 times dilution will work.

Anant Chavan
- Mumbai, Maharashtra, India
2007