You can use following methods to remove rust stain from bricks:
1. Baking Soda Paste
a) Make a paste by mixing 1 cup of baking soda with 3 tablespoons of water.
b) Apply the paste directly to the rust stains and scrub with a stiff brush.
c) Allow the paste to sit for several hours or overnight.
d) rinse the bricks thoroughly with water.
2. White Vinegar
a) Apply white vinegar directly to the rust stains.
b) Allow the vinegar to sit for several hours or overnight.
c) Scrub the bricks with a stiff brush.
d) Rinse the bricks thoroughly with water.
3. Trisodium Phosphate (TSP)
a) mix 1 cup of TSP with 1 gallon of water.
b) Apply the mixture to the rust stains and scrub with a stiff brush.
c) Allow the mixture to sit for several hours or overnight.
d) Rinse the bricks thoroughly with water.
4. Hydrogen Peroxide
a) Apply undiluted hydrogen peroxide to the rust stains.
b) Allow the hydrogen peroxide to sit for several hours or overnight.
c) Scrub the bricks with a stiff brush.
d) Rinse the bricks thoroughly with water.
5. Commercial Rust Remover
There are several commercial rust remover products available that can be used to remove rust stains from bricks.
a) Follow the directions on the product label for best results.
When using any of these methods, be sure to test an inconspicuous area first to ensure that the treatment method does not damage the bricks. Rinse the bricks thoroughly with water after treatment to remove any residual chemicals. It may be necessary to repeat the treatment to remove stubborn rust stains.