Nine copper coupons were tested for each cleaner. Initial weights were recorded, and three coupons were soiled for each contaminant using a handheld swab to cover the bottom third of the substrate. The coupons were then immersed, three at a time, in a beaker with 250ml of the chosen diluted cleaner at room temperature (68F) for ten minutes. Visual observations were taken during this time, and final weights were recorded after cleaning. This process was repeated for each cleaner on all three contaminants.