Electroplating

Discussion in 'General Electronics Chat' started by Mazaag, Sep 26, 2007.

  1. Mazaag

    Thread Starter Senior Member

    Oct 23, 2004
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    0
    Hi guys..

    I just wanted to ask, what type of chemical would I need to be able to electroplate a metal with Copper?

    And secondly, what would happen if i were to replace the DC source with an AC source?

    Thanks
     
  2. SgtWookie

    Expert

    Jul 17, 2007
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    1,728
    Look here:
    http://www.woodrow.org/teachers/chemistry/institutes/1986/exp30.html

    If you used AC instead of DC, you would likely wind up with a sulphuric acid solution that was considerably warmer than when you started, no plating of the part, and a somewhat smaller chunk of copper wire.

    Like Mr. Miyagi might've said, "Copper on... copper off..."
     
  3. arthur92710

    Active Member

    Jun 25, 2007
    307
    1
    Or you can use a diode bridge to chage 120vac to 170dc but you will surely get shocked so dont do it (does not matter how carefully you are!!)
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    No, that would be an extremely bad idea.

    For the best results, you need to use very low current. High voltage = high current = very poor results.

    Experiment using very low DC voltages on a few pieces of scrap. You may find that different materials plate better at different voltages, and with different strengths of electrolyte.

    Oh, and if you need something gold plated - take it to a jeweler or someone who specializes in gold plating. The electrolyte for that is cyanide - very easy to kill yourself if you goof up.
     
  5. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    Copper sulfate commonly called 'root killer' at the hardware store and an acid.

    http://chemmovies.unl.edu/chemistry/labs/LABS15c.html

    If you skip the acid you will get a coating but it won't want to adhere to the surface evenly. It will be very granular and erratic. I was able to make thin impressions of quarters in some cases but sometimes the copper would adhere. You want a current limited supply and as this particular link states +12V.
     
  6. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    Besides a copper anode, any copper salt solution will do. Copper cyanide gives the best results (because it also cleans the metal), but is very toxic. You are in certain risk of death if you use it, so my advice, don't.
    A very mild solution of sulphuric acid can be used along with the salt dissolved in it, but won't be necessary if the piece is already clean. Though, DO NOT use sulphuric acid if you decide to use copper cyanide, as the acid reacts with it, even in very low concentrations, releasing very poisonous hydrogen cyanide fumes (prussic acid), causing instant death. My advice is, if you decide to take the risk, use sodium hydroxide to stabilize the copper cyanide solution to pH 9.
     
  7. Mazaag

    Thread Starter Senior Member

    Oct 23, 2004
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    0

    is it the acid or the salt that isn't neccessary?

    and wouldn't the acid dissolve the object i'm trying to plate? (its made out of stainless steel)
     
  8. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    The idea of using a salt or acid in the solution is to make an electrolyte that will allow the material to be plated to be transported onto the anode (your stainless object). The copper ions have to be propelled by the potential field, but can move lots better if the water is conductive.

    Unless the acid is very concentrated, the SS won't be attacked. Unless you're using FeCl.
     
  9. cumesoftware

    Senior Member

    Apr 27, 2007
    1,330
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    It is the acid that might not be necessary.

    It depends on the grade of the stainless steel you use. But if you are unsure, you can use a low concentration of sodium hydroxide to take eventual grease out (stainless steel tolerates NaOH perfectly as it was water).

    Indeed. but it is not only ferric cloride that attacks stainless steel. Other cloride based chemicals can do so, such as cloridric acid or sodium hypocloride (used in bleach).
     
  10. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
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    If you want to plate SS (or other ferrous metal) with copper, I advise plating with nickel first, then copper. Results will be much more satisfactory.

    SS is quite resistant to most acids. Sulfuric acid is an exception. Increasing the chromium content of steel actually increases susceptibility to sulfuric acid.
     
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