Exposure to rain and humidity can cause any metal flagpole to rust. Even the ones with anti-corrosion finish will inevitably succumb to rusts as the protective finish deteriorates. Flag owners are advised to regularly check the flagpole for rust. The reason being that rust can weaken the flagpole. It would not be able to endure wind speeds it was originally rated for. This increases the likelihood of the flagpole failing during powerful winds.
What to do with a rusted flagpole depends on the severity of the corrosion. Minor surface rusts are nothing to worry about as far as structural strength is concerned. They can cleaned off with a metal cleaning solution. There are many metal cleaners available on the market. When working on a bare metal flagpole, find a cleaner that also provides protection. The difficulty of cleaning depends on the length, type of the flagpole, and foundation. Old painted flagpoles with worn paint can be repainted after cleaning to restore the protection and also the aesthetics.
For more serious corrosion, the flagpole can be reinforced. A sheet metal can be shaped and welded on to strengthen the affected areas.
A corrosion so severe that it has penetrated through the interior of the flagpole only has one solution. The flagpole must be scrapped entirely. Penetrating rusts turns sections of the flagpole dangerous brittle. In order to prevent injuries and damages to properties, the pole must be taken down and disposed of.