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removing zinc

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  • removing zinc

    I have a small hubcap that goes on an antique tricycle and will be nickel plated. The reproduction hubcap look like it has a zinc coating on it. How can I tell if it is zinc and is it easy to get off . I don't want to contaminate my plating solution.
    Mike wedein

  • #2
    Apply a small drop of muriatic acid on the plated surface.
    If it fizzes it is zinc.

    To strip off all the zinc, mix up a 25% solution of muriatic acid and water (always add acid to water when mixing!).
    Dip the part into the above acid bath.
    When the part stops fizzing the zinc will be stripped off. Should take no more then 2 minutes.
    Don’t leave the steel part in the above solution longer then necessary as it will start to pit the steel (will look almost as if it where sand blasted or worse).
    Rinse well with water, scrub the part with Dawn dishwashing detergent (the blue liquid type), rinse again and dry the part.
    The part will start flash rusting quickly. The best way I have found to prevent this is to lightly wire brush the steel part with a fine wire wheel (or a blue Nylox) brush.

    Buff the part to a killer chrome like shine.
    Wash well, (don’t touch the part with your bare hands, hook the hanger wire to the part during the wash procedure and hold the wire during rinsing), be sure it passes the water break test during rinsing (the water should sheet, not bead up on the part).

    Dip the part in nickel pickle (50/50 solution of battery acid and water) for 30 seconds.
    Rinse with distilled water for 30 seconds.
    Go hot (the part electrically connected) into the nickel bath.
    Nickel plate for at least an hour @ 65-75Ma per sq. in.
    Use large air bubble agitation in your tank (no wimpy air stones).
    Be sure you use a large anode (at least as large as the part and (2) anodes on either side of the tank works best).
    Whatever you do, don't break electrical contact during plating or lift the part out to "check it" as the plating will peel off.

    George W.
    I plate Acid Copper, Nickel, CopyChrome, Silver and 24ct Gold.
    No “real” chrome.


    • #3
      If the part is steel you might want to plate up with copper first. It is 10x easier to buff copper than it is to buff steel.



      • #4
        Ken, you are (of course) correct .
        However, I was assuming he did not have the copper plating kit.

        Also, if he is not using flash copper he will have to do a nickel strike plate of at least 1/2 hour prior to using acid copper (for his info, I know you know that).

        I go an hour on the strike because I like the nickel thick incase I sand through the first acid copper layer.
        The extra thickness of the nickel insures I won't sand through into the steel base material.

        One of these days I will have to get some flash copper to bypass the nickel strike.

        Which brings up a question, (Ken or anyone else) what do you thing as far as the durability?
        Nickel/copper/nickel verses flash copper/nickel.
        Which would hold up better on outside use (motorcycle items)?

        George W.


        • #5

          There won't be any difference in the durability. You'll need slightly more time in the tank. But frankly having worked with both, I think the flash copper (alkaline copper) yields a nicer, smoother finish for polishing and plating over later.