... metal derusting, steel and cast iron materials heat treatment, machine work cleaning. Adventage: High performance, completely derusting Cheap, working liquid ... 10 times Safe, no toxic for human beings and enviroment How to use: 1. Dilute rust remover by water, proportion 1: 4-5 ... can be adjust proportion by rusty level)2. Temperature: normal to 50C3. Treatment time: normal rusty 2-5mins deep rusty 5 ...