RUST ON PAVING

LEFT A METAL OBJECT ON PAVING AND NOW THERE IS A STUBBORN RUST MARK?. USE A NYLON BRUSH AND A MIX OF 50GR OXALIC ACID, 20GR SODIUM FLUORIDE, 15GR CITRIC ACID AND 1L OF WATER.

USE RUBBER GLOVES, AS OXALIC ACID IS HIGHLY TOXIC