I had an interesting conversation with a manufacturer recently. This poor fellow rambled on about his experience with sourcing his product from the lowest priced global suppliers that could be located. His ‘cost-saving measures’ have resulted in his product being delivered to customers damaged from the simple process of protectively packaging before shipment! My question to him; “So how much did your lowest price process cost you?” Sadly, it fell on a deaf ear as he continued expressing dissatisfaction with his results. Not only was it lost on him that he was spending a fortune to save a few pennies but he was also doing so at an immeasurable cost to his brand reputation.
What does this have to do with the application of powder coatings on architectural metal? Simply put, penny-pinching the process of applying coatings to architectural metal is more foolish than the example illustrated above. Why would we shortcut the process of applying powder coatings to architectural components when you consider the cost of repair and the immeasurable loss of reputation?
The foundation for the application of powder coatings is the preparation of the substrate metal for coating. The removal of soils and contaminants from the surface is essential, as our powder coatings are semipermeable. In other words, organic powder coatings have microscopic pores that allow for the transfer of air and moisture through the coating to the substrate. This is a critical visualization as any contaminant (total dissolved solids) that may be left on the surface after surface preparation is conductive, in large part composed of chlorides, salt, and sulfates, and may well result in a blister beneath the powder coating layer.
This is precisely why conditioned rinse waters are at the heart of any good architectural pretreatment system. Well, water and city water sources include concentrations of minerals (TDS) within their chemical makeup. These impurities within the rinse waters are left behind on the metal surface following cleaning and pretreatment!
Deionized water and reverse osmosis waters remove these minerals from the water used to rinse the part before powder coating, resulting in very little impurity left on the surface following rinsing. We can measure the purity of water by measuring the conductivity of the water. These conditioned waters typically measure less than 25 micro siemens of conductivity, while water that has not been conditioned typically measure between 150 to 300 micro Siemens, and represent a failure due to corrosion in waiting.
This lesson is worth remembering when our customers push back at recommendations to improve their processes with the utilization of clean rinse waters. After all, what will it cost them to save those few pennies in the cleaning and pretreatment of architectural metals.
Article by John Fett, Architectural Products Manager – North America