Rust stain removal on stucco can be frustrating. Even if you manage to remove it easily by washing it off it may seep back through the stucco if there is a corrosion problem in the wall. Unless the rust is entirely superficial, such as someone leaning something against the stucco causing the rust, then you should find the source of the problem to keep from having to remove the rust repeatedly.
Step 1 – Buy a Rust Remover
Get a commercial rust remover. Be sure to look at the label and see if it is safe for use on stucco. Also consider how safe the product is. Many rust removers can be toxic if not handled properly. There are some newer non-toxic rust remover formulas now available.
Step 2 – Mix the Solution
If the solution requires mixing then follow the directions on the product. Many can be mixed in a spray bottle for ease of application.
Step 3 – Spray the Area
Spray on the rust remover solution to the affected area thoroughly. Let it sit for a couple of minutes and use a brush to loosen the rust if necessary. Don’t leave it on too long or it may affect the paint on the stucco.
Step 4 – Wash it Away
Spray the area down with the nozzle of a garden hose until it is clean. Repeat as necessary.