1) Industrial coating
Found on
https://www.crosswordclues.com/clue/rust-converter
Commercial rust converters are water-based and contain two primary active ingredients: Tannic acid and an organic polymer. Tannic acid chemically converts the reddish iron oxides into bluish-black ferric tannate, a more stable material. The second active ingredient is an organic solvent such as 2-Butoxyethanol (ethylene glycol monobutyl ether, tra...
Found on
http://en.wikipedia.org/wiki/Rust_converter
No exact match found.
