3f2c04aa_ick___Cleaning___Stain_Removal__Description
[Stain] Acid Burn (iron oxide stain) [Cause] Frequently a result from the incorrect use of hydrochloric acid when cleaning, leading to iron oxide staining. [Removal] Phosphoric acid or Oxalic acid applied as per instructions in the Brick Cleaning Manual [Description] 
Yellow, orange to brown rust-like stain.
Brick | Cleaning | Stain Removal
Description