trailer/aluminum cleaner?

[Ryank]

Are aluminum trailers coated with a protective coating like an aluminum t top? If so I would be hesitant to use a brightener on it it could cause it to turn white after a while. Boaters world sells a product called alumi-guardthat with brass wool does an incredible job of making them look new. Just my 2c but from years in the wheel and auto business I have seen aluminum brighetners do Tons of near irreversible cosmetic damage.