... is good for ultrasonic, dip, human cleaning etc operation procedure of metal derusting, steel and cast iron materials heat treatment, machine ... 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 ...