Can cast alumium flower pots rust?

I knew 'sptfyr' was going to have trouble convincing you that aluminum can rust, even though she's right. Let me try to explain what's happening. Pure aluminum, like cans, won't rust, only corrode into aluminum oxide which does "not" prevent further corrosion. Only aluminum oxide applied in "anodizing" prevents further corrosion. There are two types of aluminum that can rust, one is a very exotic alloy containing iron used in the aerospace industry and the other is cheap castings. The recycled aluminum usually used in these castings is contaminated with iron millings or is in the sand used for casting. RScott

Can cast alumium flower pots rust?
While aluminum does corrode you would normally call aluminum oxide rather than rust.
Reply:Aluminum will corrode, but not rust. Aluminum corrosion is aluminum oxide, a very hard material that actually protects the aluminum from further corrosion. Aluminum oxide corrosion also looks a lot more like aluminum so it isn't as easy to notice as rusted iron.
Reply:Yes, they can. If they get seriously rusty then wash them out as best you can and seal them with rust sealer. Other than they should be fine. I have some with rust and I like the shabby chic look of them. The plants don't seem to mind.
Reply:They shouldn't. If they are, you don't have aluminum, you have steel or iron pots. Rust is oxidation of the iron contained in steel. Aluminum oxidation is just a slightly duller version of aluminum. Your pots will lose that shiny silvery aluminum finish in lieu of a dull white/silver finish. You can just use any abrasive to restore the original sheen.