Instructables

How can I prevent aluminum jewelry from oxidizing?

In my instructable about making an aluminum ring, I made two aluminum rings, one for my girlfriend and one for myself. Mine is still fine; however, hers keeps turning black (oxidizing). I understand this is because she is a girl and her skin pH is different than mine (more basic); but I am curious if there are any techniques on how to prevent this from happening. The ring needs to be polished using aluminum cleaner every other week, but if there was a way to keep its mirror finish, that would be fantastic. Thank you!

jtobako5 years ago
If hers has a black coating (rather than turning her skin black) it would be because her skin is anodizing the ring-little bits of whatever she puts on her hands is filling the tiny aluminum oxide tubes that anodizing creates (and holds the dies that color anodized aluminum). You may just need to seal the aluminum-the final step after dying in anodizing.
j626no (author)  jtobako5 years ago
It has never been anodized. It is bare aluminum.

Maybe I'm misunderstanding...are you saying that I could just purchase aluminum sealer for post-anodizing to solve the problem?
jtobako j626no5 years ago
Anodizing is just making the oxide layer thicker.

Apparently, it's easier than that. According to here all you need to do to seal it is boil it for half an hour.

kelseymh5 years ago
Anodize them, or paint on a clear lacquer coat. Exposed aluminum metal oxidizes naturally and fairly quickly.
j626no (author)  kelseymh5 years ago
I know it oxidizes quickly...but my ring has the natural, clear oxidized coating. Hers has a black coating. Is there any way I can anodize them myself? Would clear lacquer make them sticky? (remember that it's a ring and on her hand all the time)
frollard j626no5 years ago
laquer can cause allergy problems on the rings.

Anodizing can be done with high voltages, or high temperatures, or chemical reaction.
The anode of a redox reaction is less willing to take on electrons - or oxidize. It's basically changing the chemical layer on top of the aluminium.

These guys sell kits of chemicals to work with large parts - you just need to search harder than I did (this was top listing for "how to anodize aluminium"
http://www.focuser.com/atm/anodize/anodize.html
http://astro.neutral.org/anodise.shtml

these guys have a cool anodozing tutorial.