Removing plaster from bricks can be cumbersome. Because of the porous nature of bricks and the mortar that holds them together, plaster seats deeply into the pours and makes it almost impossible to restored the brick surface. Luckily, there are a few effective ways to remove plaster from brick. Depending on the size of the job, you shouldn't be tied up longer than a day or two.
Wet the plaster using a garden hose. This will keep down on any unnecessary dust. Spray water on the plaster until the water has thoroughly soaked into the wall.
Scrape any loose plaster away from the brick using a brick scraper.
Remove the plaster that was left behind by the scraper. Using the right angle grinder and a wire wheel attachment, remove the plaster in a light, circular motion. Wear your safety glasses because this step will certainly distribute material in all directions, including your eyes.
Apply brick cleaner to the remaining material that is embedded deep into the pours. Mix the cleaner into a 5 gallon bucket and follow the directions for use. Apply the cleaner using a stiff acid brush with a handle. Allow the cleaner to sit for 10 to 15 minutes before removal.
Remove the brick cleaner with a pressure washer that is above 1500 psi. You want to remove any remaining plaster that may remain in the mortar joints and brick. Be careful not to blow the joints out with the pressure washer.
Always wear safety glasses. Do not inhale the brick cleaner into your lungs. Wear rubber gloves when handling the cleaner.