I have a brick house with a wall inside the garage that was painted, and after a few years another coat of paint was applied, for a total time of about 25 years on the wall. The second coat, however, was a paint meant for steel, and is now turning into a fine powder. I can scrape the loose paint, but how do I safely and fully remove the powdery paint from the walls? I thought I could use a steel brush, but that’ll send the steel paint into the air. Even with a face mask, I’m afraid it will get into my lungs.