Stop in for a cup of coffee

Coke dissolves rust (iron oxide) because in contains phosphoric acid. The PA reacts with the iron oxide and converts it to soft iron phosphate.

Coke is only 0.0017% phosphoric acid. You can make your own solution of 1% for around $1 per gallon and it will be far more effective. Phosphoric acid also does not react with the steel much so it only dissolves the rust leaving the steel intact.

Phosphoric acid is the “secret ingredient” in the POR-15 products.