I am prepping an existing slab for acid staining. There is paint splatter & caulk stains on concrete I must get up. Also, I would like to remove thin set in kitchen. Is there a Blastrac product that would take up the stains like a sander would? Can you control how much concrete is lost? Would a Blastrac shotblaster leave obvious marks or patterns on the floor? Where can I find a rental in San Antonio Texas? Thanks for any help