Electrolysis finish

Discussion in 'Finishing Techniques' started by MichaelMueller, Oct 13, 2011.

  1. MichaelMueller
    MichaelMueller Well-Known Member
    If you recieve a silver item from shapeways, you may find it too bright and glossy.
    Using electrolysis is an easy way to make the silver darker so it gets more contrast and an "ancient" look.
    In my opinion, the technique is pretty harmless, but please be aware that you're doing this at your own risk!

    What you need:
    - Old Spoon
    - Old AC/DC power supply or power transformer
    - Baking Soda
    - Glass of water


    1. Dissolve baking soda.
    Dissolve some baking soda in a glass of water. I've used approximately one teaspoon of it for 400 ml of water.


    2. Prepare the power supply.
    I would recommend a 6-12 volt power supply with 500-1000 mA (=1 Amper). More amper would make it work faster but this is where you enter the "danger zone", so I wouldn't use a stronger power supply for this project. ;)
    Make sure the power supply is "DC" and has a cable that's long enough (about 1 m).
    If there is still a plug on the supply, cut it off and remove the insulation on the two wires. Now it should look similar to the one in the picture.


    To check which contact has "plus" and which one has "minus" just plug in the power supply and put both wires in the glass with the water and baking soda.
    Make sure that the two wires are separated from each other. A contact could damage the power supply. After putting it in the water, you'll see that one wire is turning dark. This is the "plus" wire. There should be bubbles coming from the other one. This is the "minus" contact.
    The best thing is to mark the "plus" wire with some tape so there won't be a mix-up.

    3. Put everything together.
    Make sure the power supply is disconnected. Connect the spoon with the "minus" cable by wrapping the blank wire around it. After that, do the same with the silver item and the "plus" wire. Put the connected spoon and the item in the water and keep them separated from each other. Plug in the power supply and enjoy the show.


    4. Check the silver item.
    You should stop the electrolysis after a minute to check if the silver is already dark enough. Make sure you disconnect the power supply first. You should clean the silver with e.g. an old toothbrush. This also ensures the electric conductivity to the wire.
    If it is not yet ready, put it back on the wire and turn on the power supply again.
    I usually do this 5 to10 times till the silver is kind of black.


    5. Polish the silver item.
    A black silver item isn't nice at all. The embossed parts should be polished now so these areas are becoming glossy again. I use fine sandpaper (800-grit) for this.
    After this, it should look similiar to the picture at the top.

    Helpful links:
    http://www.mycoincollecting.com/collecting/cleaning-coins-el ectrolysis.html

    Please let me know if you know how to improve this technique.
    Have fun!


  2. erckgillis
    erckgillis New Member
    As a Jeweler we use simple chemical preparations to "Patina" silver or other metals. For the silver traditionalist use liver of sulfur or Potassium Sulfide (K2S).

    While this works well your results can vary greatly from just the black by using a warm solution and adding a tablespoon of ammonia (NH4). These can vary the Silver from gray to Green and Purple to iridescent to the black.

    A quick wipe on solution of Copper Sulfate "Cupric Sulfate" ( CuSO4) will also give instant black.

    then just wipe or polish the highlights back.

    Some of these solutions will work with copper/brass/bronze findings as well so you can match to your other components.


  3. MichaelMueller
    MichaelMueller Well-Known Member
    I guess sulphurliver is really the best way. I've used it too, with great results. Unfortunately it's slightly toxic and it seems that only jewelers are allowed to buy it... at least here in germany.
    Electrolysis works fine too, but I would prefer sulphurliver if I could get my hands on it, cause it seems to be more "mild" to the silver material.
  4. erckgillis
    erckgillis New Member
    you can make Potassium Sulfide at home with potassium permanganate and Sulfur


    Try this over a bath of Hydrogen peroxide, the K2S will fall from the reaction into the H2O2 and create the solution you need.

    heat and add NH4!

  5. 1ko
    1ko New Member
    Looks really nice this way!
    Does it work also for gold plated finish?