"Electroforming of Aluminum"

A. Dear Mr. Zoheir:

You will not be able to electroform (or even electroplate) aluminum from a typical aqueous plating tank because it is too active a metal (water separates into hydrogen and oxygen before aluminum ions reduce to metallic form). Copper can be electroformed as thick as you want, probably. Look up some formulations for a bright acid copper plating bath, and that should suffice for electroforming. Good luck.

A. In the previous response I told the inquirer that he would not be able to electroform aluminum, Paul. I don't want to repeat that, and thus imply that I am insisting upon the impossibility of it. I don't like to say that anything is forever impossible.

But the gist of the problem is that aluminum (unlike most other metals) is more electronegative than the hydrogen in water itself. So when you put electricity into an aqueous solution in an attempt to electroplate it, the hydrogen in the water is reduced and "deposits" far more readily than any dissolved aluminum does.

It is possible to plate aluminum out of solutions of organic solvents in a sealed oxygen-free environment. It is covered by patent and not widely done, but it can be done. Electroforming is a whole 'nother layer of complexity. So again, I don't say it's impossible, but a self-confessed "rank amateur" is not going to be able to do it short of devoting a couple of decades of his life to it :-)

A. Electroforming of aluminum is certainly possible and was investigated by General Electric under a contract to NASA in 1965. Please see ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19650012755_1965012755.pdf

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Ed. update Nov. 2020: That link is now broken, but that article "ELECTROFORMING ALUMINUM FOR SOLAR ENERGY CONCENTRATORS" is now available at https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19650012755.pdf

Thanks Kevin. Corporations who are interested in the possibility of aluminum electroforming, and who are capable of substantial investments, may find that link very interesting and useful. 50 years later has anyone ever implemented it?

I still think "a beginner in electroplating" should try copper for electroforming rather than aluminum, and that a "rank amateur to plating" is not going to be able to electroform aluminum. Thanks again for the link, though --interesting!

Regards,