bigfootpressurewashi
New member
What would be the best chem to remove black stains from painted concrete and red brick?
chem question
- Thread starter bigfootpressurewashi
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MMI Enterprises
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If stains are organic such as from mold then use a cleaner containing sodium hypochlorite (bleach).
If stains are from smoke or soot deposits use a cleaner containing a blend of acids such as hydrochloric (muriatic pool acid), phosphoric, sulferic, etc..
Can also use solvent blends or xylene for such deposits, especially if they involve synthetics such as oils, greases, tar, asphalt, etc., when you know the coating or surface will not be damaged. Since you mention painted concrete it would have to be a permenant type catalyzed finish in order to use such solvents.
Other options that can also damage paint are TSP(tri sodium phosphate), Sodium hydroxide (lye, caustic, oven cleaner), and butyl cellosolve (butyl, 2-butoxi). For unpainted surfaces though these three are the bomb and tend to be the goto products for general cleaning or heavy duty cleaning or prep for painting.
If stains are from smoke or soot deposits use a cleaner containing a blend of acids such as hydrochloric (muriatic pool acid), phosphoric, sulferic, etc..
Can also use solvent blends or xylene for such deposits, especially if they involve synthetics such as oils, greases, tar, asphalt, etc., when you know the coating or surface will not be damaged. Since you mention painted concrete it would have to be a permenant type catalyzed finish in order to use such solvents.
Other options that can also damage paint are TSP(tri sodium phosphate), Sodium hydroxide (lye, caustic, oven cleaner), and butyl cellosolve (butyl, 2-butoxi). For unpainted surfaces though these three are the bomb and tend to be the goto products for general cleaning or heavy duty cleaning or prep for painting.
bigfootpressurewashi
New member
I will try to get pics. It looks like a black mold, thats running down the building.