Applying Rozone concrete removal foam is the safer way of softening and removing old mortar found on masonry tools, general construction equipment, and vehicles. Its mild acid and foaming agent also dislodge unwanted concrete deposits from glass, metal, most plastic, painted and wood surfaces. It normally works in 10 to 15 minutes depending on the application and the soak time will really depend in the thickness of conrete you are trying to remove. The general recommended time would be about 10 minutes but thicker materials may take 30 or more through repeated applications. It is important to keep the material wet with the concrete removal foam and not let it dry out.

You must apply it to the material when it is dry. Any water on the material will neutralize the effects of the concrete removal foam and its effectiveness will be reduced. 

If you are cleaning equipment on concrete, ensure you cover the area or wet it down first so as to prevent the concrete removal foam activating on the surface which you dont want cleaned. 

Alwasy test a small area first to both establish how much soak time is needed and check reaction on surface