Important: - Test on a small area before general application. Not suitable for use on acid-sensitive surfaces such as limestone, marble or other acid-sensitive metals and materials. Some stones may become slightly darker in appearance following use. This fades over time.

1. Ensure surface is free from loose dirt and dust
2. Dilute following package instructions in water. 
3. Apply the solution to the surface and spread out evenly. For external applications, garden sprayers are recommended.
4. For more severe cases agitate the surface using a short-haired scrubbing brush or black emulsifying pad. Let sit for 3-6 hours
5. Rinse with plenty of clean water. If traces of rust remain, repeat the process accordingly.
6.  Further treatment: Sealing with an impregnating sealer will render the surface resistant to water penetration, this greatly reduces the likelihood of the discolouration occurring again. 

Extremely severe cases dilute 1:1 with water Severe cases dilute 1:2 with water Mild cases dilute 1:3 with water