Simple electrical question

Discussion in 'General Electronics Chat' started by pepper crab, Feb 1, 2011.

  1. pepper crab

    Thread Starter New Member

    Feb 1, 2011
    I'm a total newbie when it comes to all things to do with electricity. I'm interested in doing an electrolysis project for fun, and need some advice.

    I have a 12V 10A battery charger. I have a pail of water mixed with some chemicals to improve conductivity. I have a 5 pieces of metal, 1 is a piece I want to derust, and 4 are the sacrificial metals. I need 4 sacrificial pieces because this operation is line of sight, meaning the surface to be derusted has to be in direct line of sight with the sacrificial piece.

    Here's the plan.
    1) First I place the 4 sacrificial pieces on the edge of the pail, one each in the N, S, E and W positions.

    2) I place the piece to be cleaned in the centre of the pail without touching any of the other pieces.

    3) I take the negative cable of the charger and connect it to the piece I want to clean.

    4) I take the positive cable and clamp it to one of the sacrificial pieces, say the one on the N position.

    5) I use several small wires with crocodile clips on both ends, to connect the sacrificial piece in the N position to those in the E, S and W positions.

    How thick does the wires I use in (5), the small pieces with crocodile clips at both ends, need to be?

    The charger can hit 10A max, and the pieces of wire I bought are the normal kind used for electronics stuff. Will it totally burn through the wire?

    If yes, any ideas for connecting up the 4 sacrificial pieces electrically in a safe way?

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    I kinda doubt if the exact relationship of anode to cathode matters. If you get better results with one anode, you may need to rotate the cathode piece to get even results.

    I would suggest that you use a limiting resistor to insure you don't pull over 10 amps. If you can find a 2 ohm 25 watt wirewound resistor, it would be about right. That should be enough to limit current even if you accidently short the leads.
  3. Markd77

    Senior Member

    Sep 7, 2009
    Which chemicals?
    Salt would be a bad choice because of the chlorine released.
  4. someonesdad

    Senior Member

    Jul 7, 2009
    This is a common technique and there are good references on the web. Google for "electrolytic rust removal" and you'll find more reading than you know what to do with.

    I've used the method to clean rusted files. It works great. The best electrode is a sheet of sheet stainless steel, but use what you have on hand. I used baking soda to increase the conductivity of the water. You don't need a lot. A 12 volt battery charger works just fine. Make sure you get the connection polarity correct.

    If everything works correctly, you'll wind up with an ex-rusted surface that is a matte gray and a disgusting brown foamy solution in the water. :p