The surface becomes etched and clean which allows for the proper adhesion of a new coating.
Cleaning oil from concrete with muriatic acid.
Scrub the gray stain with a solution of 1 cup liquid chlorine bleach 1 cup powdered laundry detergent and 1 gallon of very hot water.
While some stains can be rinsed away with a pressure washer tougher stains such as rust require an acid based cleaner like muriatic acid.
Make sure the detergent you use is ammonia free.
Muriatic acid is diluted hydrochloric acid and is a very potent chemical.
Before washing your driveway with muriatic acid try a degreaser on oil stains and a solution of one part bleach to three parts water on mold and mildew.
Mixing ammonia with bleach creates a lethal gas similar to mustard gas.
Despite its effectiveness muriatic acid should be used on concrete stains only if you ve tried gentler alternatives to no avail.
Mold rust and other stains can mar the clean beauty of your concrete lessening the visual impact and even the curb appeal of your property.