Not in my garage but the surface of some insulators that I recently purchased. My muratic acid bath doesn't seem to want to remove what I think is some sort of mineral deposits on the surface. At first I thought what was there was a sign of enviromentle wear like sand blasting being the insulators came from a south western state. When I scraped the surface with a blade it came off and the glass shined beneath. You can see in a section where I sraped on the insulator in my pic. Any ideas of what might remove these minerals faster for me?