Dave its difficult to make out the before and after exposed areas real well because your pictures usually vary with different lighting from shot to shot. yes the exposed copper is generally a reddish in color but the stronger strength CLR will exploit these bare spots and discolor the metal even further and sometimes even undermine the gilt . the stronger the strength the faster it can happen , diluting it and only using for a few seconds at a time as opposed to saoking in full strength can slow this process and give you a chance to stop before that happens . does this make sense to you ??Originally Posted by HEAVYMETALNUT link=topic=13454.msg142390#msg142390 date=1370268707