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I'm looking to plate some aluminum with silver using a basic solution.

My first attempt was to use sodium carbonate to make silver acetate. I sped up the process using hydrogen peroxide. I used the silver acetate as the ion source.

This simply did not work to plate any aluminum.

I concluded that this is because the aluminum was oxidized, preventing a plating from sticking.

I've come to the conclusion that the main problem with plating into aluminum is that it's able to rapidly form a highly resilient oxide layer.

Are there any common ways to prevent this oxide layer from forming? More to the point, are there any common methods to plate aluminum, specifically with silver?

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    $\begingroup$ It is simply impossible in aqueous solution. $\endgroup$
    – Karl
    Jul 18, 2020 at 21:36
  • $\begingroup$ @Karl if I used an oil with sufficient electrolyte? $\endgroup$
    – tuskiomi
    Jul 18, 2020 at 21:37
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    $\begingroup$ You need a blank metallic surface, and a water-free electrolyte with silver ions in it. Im sure that´s somehow possible. Affordable? No. Can be done outside a well-equipped chemical laboratory? No. Sorry, but forget it. $\endgroup$
    – Karl
    Jul 18, 2020 at 21:48
  • $\begingroup$ Apparently, aluminum can be electroless nickel-phosphorus plated, as per en.wikipedia.org/wiki/Electroless_nickel-phosphorus_plating. Then the nickel plating can be silver plated, which is a standard scenario. You might also search this site for silver plating questions and answers. So the trick is several stages, which is not uncommon. Best of success! $\endgroup$
    – Ed V
    Jul 22, 2020 at 19:07

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I’m so confused now. I did this when I first started experimenting with electrochemistry (when I didn’t know what I was doing) I was using anything I had in my garage as an anode and somehow I copper plated this aluminum speed square.

All that I remember is that I was using CuSO4 I made using a copper anode and copper cathode in a vase filled with H2SO4 in distilled water (thanks NurdRage), where I switched out the cathode for this tool and it came out plated, and the strike is still totally solid!

Now that I know that it is technically impossible, I’m sure I’ll never be able to recreate the “experiment.”

Anyone have any ideas what could have contributed to my accidental success?

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  • $\begingroup$ You sure it wasn't steel? $\endgroup$
    – tuskiomi
    Jan 10, 2021 at 2:57
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    $\begingroup$ @tuskiomi definitely not steel. Their website says “heavy gauge aerospace aluminum alloy billet” so I tried contacting them about what the alloy is, but aren’t really counting on them telling me! Do you have any idea what alloy would allow plating in a copper sulfide electrolyte? $\endgroup$ Jan 10, 2021 at 4:10
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No ! There are no method for plating aluminum. Thousands of people have tried. In vain. It is impossible to prevent the formation of a thin layer of aluminum oxide which is waterproof at the surface of the metal. The only way of preventing it is to dip a piece of aluminum in a solution of mercuric chloride. This produces a reaction $$\ce{2 Al + 3 HgCl2 -> 3 Hg + 2 AlCl_3}$$ and the mercury makes an alloy (or amalgam) with not yet oxidized aluminum, and this prevents the formation of the continuous oxide layer. But this alloy does not prevent the oxidation of Al in contact with air. The oxidation of the amalgamated aluminum proceeds with such a speed that the growth of the aluminum oxide filaments can be seen by the naked eye. In a couple of minutes, white filaments of oxide grow to become one or two centimeters long. This extraordinary phenomena stops when the mercury has been removed from the surface by the growing oxide filaments. Of course, today, it is forbidden to carry out such experiments, because of the mercury toxicity. Fifty years ago, it was allowed. I do remember.

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  • $\begingroup$ I know this is an old answer, but if aluminum forms an oxide layer so fast, can't you move oxygen out of the environment? $\endgroup$
    – tuskiomi
    Jun 30, 2023 at 21:25
  • $\begingroup$ How move oxygen out of the environment ? $\endgroup$
    – Maurice
    Jul 1, 2023 at 8:26
  • $\begingroup$ Replace atmosphere with pure nitrogen perhaps, or argon, or CO2. These gasses are commonly available for welding purposes and such. $\endgroup$
    – Dennis
    Apr 13 at 6:11
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Pure simple straightforward electroplating is a no go onto aluminum, however aluminum can be electroplated onto other metals and itself, using chloride solutions and secondary reactions can interact with the oxide layer not enough to dissolve it but enough that a sufficient supply of surfactants will allow the softened oxide layer to be pulled away

I personally messed around with some poorly translated USSR documents on the subject alongside you tube videos for electroless plating of copper on AL in the purpose of getting a decent solder joint with very limited "success" (it immediately oxidized the copper, but I found the effect kind of wood like in appearance and used it decoratively anyways) Some things I found to help was magnesium salts, an acidic solution, dawn brand dishsoap, boiling everything I could prior to use to remove as much trapped air and oxygen as possible, and using mechanical means to remove the oxide layer while the aluminum was submerged in the solution. There even where a few batches that turned out copper colored and maintained that coloration for several days before turning brown.

This is of course my progress so far doing something entirely different, but it is on the same base metal.

There are also older procedures for electroless and electroplating on titanium, they used some very.. uh. Toxic materials. Molten salt baths are the standard and in the end you may have to use a "low" temperature salt bath to get good repeatable quality electroplating, but I see it as a minor thing, 180°c is home candy making Temps, its definitely home chemistry Temps, just not common.

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  • $\begingroup$ This is some really cool info.. I never thought about doing a salt bath... I suppose you do such a thing outside, I can't imagine salt plating is pleasant in any form. $\endgroup$
    – tuskiomi
    Jun 30, 2023 at 21:30

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