Sorry if this is a bit off-topic... our patio just went in this year, Unilock Beacon Hill Flagstone pavers. We got some new lounge chairs too and when it rains, water seems to collect inside the hollow metal frames of the lounge chairs, where it stagnates for a while and then comes out all rust-laden. We found a few of these big rust splotches on the patio under the chairs.
Anyone here have hands-on experience with cleaning large rust stains from pavers? I know you can use muriatic acid but it's considered dangerous. Unilock recommends a product of their own called AcidClean which is phosphoric acid. Then I found this Concrete Rust Remover online which sounds perfect but I'm not sure what's in it. The MSDS just says "proprietary product mixture" but from the hazards (decomposition -> "sulfur oxides when exposed to strong acids") I'm guessing it's sodium hydrosulfite.
Which of these would you use, or something else?
Anyone here have hands-on experience with cleaning large rust stains from pavers? I know you can use muriatic acid but it's considered dangerous. Unilock recommends a product of their own called AcidClean which is phosphoric acid. Then I found this Concrete Rust Remover online which sounds perfect but I'm not sure what's in it. The MSDS just says "proprietary product mixture" but from the hazards (decomposition -> "sulfur oxides when exposed to strong acids") I'm guessing it's sodium hydrosulfite.
Which of these would you use, or something else?