Friday, May 10, 2013

Alternative Pickle for Brass and Nickel Silver

Last year I wrote a post on pickling sterling silver with a mixture of vinegar and salt, a more eco-friendly alternative to pickling with Sparex. I'm still using that method for sterling, but have moved onto something else for brass and nickel silver.

While vinegar and salt worked okay with brass, it often left a hard-to-remove pink film on the surface, which I'd have to remove by sanding. Needless to say, this can take a lot of time.

After some digging, I found a better method, again, using common household supplies: vinegar and hydrogen peroxide, aka Peracetic Acid.

Peracetic Acid is used to disinfect surfaces and even food, such as fruits, veggies, and raw meat. Pardon my hyperbole, but it works miracles on brass and nickel and rivals commercial solutions, such as Sparex.

Here's what I do:  

  • In a glass or plastic bowl or jar, mix two parts distilled white vinegar with one part hydrogen peroxide
  • After soldering, submerge your piece in the mixture until all oxidation is removed. Use tongs.* Give it at least 20 minutes.
  • Occasionally agitate the piece to hasten the pickling process. Brushing your piece with a paint brush while it's submerged can speed things up.
  • Remove your piece using tongs, rinse it off, and voila--your metal is clean!
  • The surface of the brass will often look crystallized. Remedy this by gently polishing the piece with steel wool or buffing with very fine sand paper.
  • Finish as usual.

*Even though Peracetic Acid is used in food cleaners, disinfectants, etc. I recommend using it with caution. Use the mixture in a ventilated space and use tongs when handling your piece.

Here's a before-and-after of the first piece I pickled. I left it in for about 15-20 minutes. The mixture will turn blue. As the solution becomes saturated, it will become an even brighter blue than what you see in the solution below.


Disposal

Unfortunately, the mixture isn't reusable, so I recommend pickling in batches. After some experimentation, I found the solution can be used for several pieces. It tends to work until it's bright blue and cloudy. For disposal, I dilute the mixture with water and run it down the drain, or I let it sit on my back porch until it evaporates.  I'm not clear on the safest method for disposal, so if you know something, please share your thoughts in the comments!

I hope this helps!

Happy Spring,
Angela


Sources
Alternative Metals Tips for Soldering Copper and Brass from Jewelry Making Daily

Bill Sealy's Pickle Formulas


9 comments:

  1. Thanks, Tim. That makes sense to my non-chemist mind as well :) This mixture is used to disinfect meat and as a fruit and vegetable wash, so I would think a diluted form would be safe for the drain or toilet.

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    1. A challenge with this is that acetic acid and peroxide are ok to flush... but not the dissolved copper as its toxic to fish and I understand that most municipalities dont/cant treat for removing copper.

      Sone folks absorb it on clay cat litter and dispose in trash.
      (I am a chemist)

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  2. I have been using this for a while, and sometimes it works, and sometimes it does half way. I am not sure why. sometimes it works instantly. I have been putting my hands in it with out any repercussion that I know of, but may stop. I do think it is best to not stock up on peroxide, because it seems to go stale, and loose some energy, even if the bottle is sealed.

    Roxy Lentz

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  3. Hi Roxy! Thanks for posting. I agree the solution can be a little unpredictable. The finishing work I do after pickling usually takes everything off, though. And I tend to mix a new batch once the solution is saturated. I wonder if it would work more consistently with heat (in a crock pot, perhaps)? Might be worth a try. As for touching the solution, I'm more concerned about it when it becomes saturated with oxides and flux. I have sensitive skin, and am cautious in general about fumes and chemicals, so I try to keep my hands out of it by using tweezers and then dipping in water before touching the pieces. Thanks for the peroxide tip--good to know!

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  4. Hi Angela,

    What kind of solder and flux do you use to solder your brass?

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    1. Hi Audrey,

      I use silver solder and for flux I'm currently using Grifflux. I've found Handyflux and Batterns to be decent fluxes as well.

      Hope that helps!
      Angela

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  5. With regard to the copper, just as with normal pickle, it isn’t the best thing to pour down the drain. I usually neutralize the acid with baking soda and lots of water, which I’ve heard (though I’m not 100% sure) helps recrystallize some of the copper, making it safer to dump. I believe, and I’m about to try this myself, that after you neutralize the acid, you can set the liquid aside to evaporate and then chuck the remnants. I’ll let you know if I actually figure it out!

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  6. Have you used this for nickel as well? Do you regular pickle first? I have used this method on pieces I have made with copper and brass together and it works like a charm. I love silver, but I am going to move on to nickel as a cheaper alternative. I’m just not sure how to pickle it and if I should put it in my regular pickle pot.

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  7. Hi! I randomly came across your post while searching for a question I have perhaps you can help? I've been using this solution for a while now for my brass pieces and usually works great but lately my pieces are turning a dark splotchy black while in the super pickle. It's so weird I don't know why it's happening. Ha! Of course I can buff it out but it's annoying and perplexing and wondering if anyone else has experienced this? Thank you!

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