What corrodes aluminum anyways?
When aluminum corrodes it oxidizes. Its own oxide then protects it from further corrosion. So, if you want to make it less likely to corrode then you oxidize it artificially (electro-chemically.) It is corroded to some degree by air and water (i.e. weather), but the rate drops off as it develops oxidation. It is much more susceptible to damage by acids. Sorry if my definitions were too “dictionary.” Tree grates are usually cast iron – not steel (which is not to say that your city is not using steel, but I don’t have any info to give you on that.) Cast iron does cause rust marks. Advantages are low tooling and production costs, ability to be easily cast into any complex shape, and very high hardness and wear resistance. If I wanted to know more advantages and disadvantages of various types/materials of tree gratings I would really call some reps who sell them. That would also be my approach to finding out specific unit costs for various elements, finishes and processes. You can also get
