Coupons of stainless steel and copper were selected and arranged on trays, so that each cleaner had an assigned set of each surface. Before taking initial weights coupons were wiped down with Kimwipes. After taking weights the coupons were promptly soiled and reweighed. All cleaners were gathered in respective bottles and beakers. A stir bar was used in conjunction with a heating plate equipped to stir the solutions. The coupons were added to the beakers three of a kind at one time, and then allowed to sit in the stirred solution at room temperature for 15 minutes, in 5 minute increments while observations were taken. Finally, clean weights were taken at the end of all the testing.
When the experiment began, the first batch of coupons cleaned still contained wet soil and therefore the removal was easier. The rest of the coupons dried and removal was less facilitated, then. Many of the cleaners left a film behind and white residue after drying. Honeywell’s Solstice PF performed the worst, perhaps because it was cleaned last and the soil had dried so much by then. White residue was visible while the coupons were in the solution, there were no signs of peeling and white residue persisted once the coupons dried. It seemed that not the entire surface was penetrated by the cleaner, as patches of soil were still visible on the coupons. Although percent removals were quite high for most of the cleaners, the visuals were not nearly as satisfactory. In conclusion, the experiment was unsuccessful and further testing will be required. In this case, the next step will be heated immersion with stir bar.