• Neato
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    42 months ago

    Real question: how can you tell the difference between rust and a supposed patina that forms and changes over time? I’m not talking about Cybertrucks, those are just rusting. But some chromium based metals supposedly can do this over time and can look like rust initially. Does rust usually cause pitting or flaking?

    • @interrobang@lemmy.blahaj.zone
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      92 months ago

      No, patina is a thin layer of oxidation on top of the actual material from contact with the air.

      Rust is corrosion from air + moisture, and causes pitting and flaking. Patina should just sit over the surface, but not distort the thing it’s on.

      There is more nuance to it, but patina is on top, rust is the actual thing turning into rust

      • Neato
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        32 months ago

        Thanks. I’ve got a metal decoration made from weathering steel that has what appears to be rust spots all over it. Allegedly it will do this onto the entire surface and eventually fade into a darker color. But it’s been pretty slow. But no putting or flaking at least.