Proper cleaning and pretreatment of metals are critical components of the high-performance paint finish used for architectural metal panels. To obtain proper long-term performance of coatings used for architectural metal panels, metal must be cleaned of any contaminants associated with the steel or aluminum processing/ manufacturing. Pretreatments then convert the metal surface into a non-metallic coating to obtain proper adhesion by a chemical/physical bond. This increases the durability of both the base metal and paint finish by providing an additional barrier layer and protecting areas where damage to the paint may occur during the life of the metal panels.
Many different types of pretreatment systems are currently available. The performance of each individual pretreatment may vary depending upon the metals that are being treated. This includes the overlying paint system and the geographical area of the country where the architectural metal panels are being installed. Most locations are identified as rural, industrial, marine or severe marine environments.
The most commonly used pretreatments for architectural metal panels are as follows:
Complex oxides – used on hot dip galvanized steels
Complex oxides provide excellent flexibility in the forming operation of steel panels. Typically, they do not provide the required additional barrier protection and steel surface conversion in environments subject to acid rain; industrial chemicals and fumes; or marine and severe coastal locations. Their use is acceptable in areas where these contaminants are not present in high degree.
Zinc phosphates – used on hot dip galvanized steels
Zinc phosphates typically provide increased corrosion resistance of galvanized steels by the surface conversion during the pretreatment process. They have been used commercially for over 100 years. However, they have undergone evolutionary improvements, including the use of additives and refinement of the process which have increased the durability of steel panels that have difficult forming requirements. This pretreatment is commonly recommended when the galvanized steel panel is subject to aggressive environments such as areas subject to acid rain; industrial chemicals and fumes; or marine and severe coastal locations.
Complex chrome oxides – used on aluminum/zinc alloy coated steels and aluminum
Complex chrome oxides have been used extensively on both aluminum/zinc alloy coated steels and aluminum. They are available as conversion coatings as well as dry-in-place coatings. Complex chrome oxides provide excellent formability as well as field-proven corrosion resistance to the base metals.
New emerging technologies are forthcoming in the metal pretreatment industry. Some, such as chrome-free, are already commercially available. The new technologies are being developed to improve or maintain the performance of pretreatments while offering cleaner methods. Therefore reducing the environmental impact of pretreatments.
Due to the varying types of base metals, pretreatments, and paint systems used, the building owner should consult with their architectural metal supplier. This will ensure all aspects of the coating system are considered prior to the selection of materials.
The Superior finish system is durable fluoropolymer coating system consisting of a .2 mil primer and a .8 mil top coat. This premium finish is a two coat system that provides outstanding aesthetics and durability in a wide range of architectural applications while being the most economical high-end coating for building product applications.
Enhanced Primer Superior Finish
This finish provides all of the outstanding features of the conventional Superior Finish System but has additional durability with a higher build .5 mil thick primer. This additional thickness of primer provides greater durability of the coating system for use in highly aggressive industrial and marine applications. The enhanced primer thickness can actually increase corrosion resistance of the metal panel system.
Superior Plus Clear Finish
This three coat finish system consists of our Superior Finish system with an added .6 mil clear top coat applied in a separate pass on the coating line. This additional layer of a clear fluoropolymer coating is designed to enhance the color retention, particularly when deeper, more vibrant colors are being considered. Overall finish system thickness is 1.6 mil.
Superior Metallic finish is a fluoropolymer coating that provides a metallic appearance. Consisting of a .2 mil primer system with a .8 mil top coat, these metallic finishes provide color shading variations on the building depending upon sunlight and panel orientation.
Superior Metallic Plus Clear
The Superior Metallic Plus finishes are coatings that provide the metallic finish with the additional layer of clear top coat protection. Finish consists of .2 mil primer with a .8 mil top coat and a .6 mil clear coat. Overall finish system thickness is 1.6 mil.
Vivid Metallic Finish
The Vivid Metallic finish system consists of a unique blending of pigments in a base coat and top coat of the fluoropolymer finish to create a dramatic shadowing effect of the installed metal panel system. Colors often appear to change as you view the building from various angles. This coating consists of a .2 mil primer system with a .8 mil base coat and a .8 mil top coat, providing excellent durability combined with striking aesthetics.