Metal Construction News, February 2021

SPECIAL FEATURE Know Your Coatings Understanding the types of coatings and their characteristics can help you create a lasting impression Metal panels come in a wide variety of colors and types of coatings The technology in coatings makes sure that they not only look nice but also protect the metal panels from moisture and pollution Before deciding on which type of coating is right for your next metal panel project here are the basics of whats involved in the coatings and the types of aesthetic options available Coatings are formulated specifi cally to protect the substrate and withstand in this case extreme weather conditions says Jeff Alexander vice president of sales for Minneapolisbased Sherwin Williams Coil Coatings All while protecting the substrate and maintaining the beautiful aesthetic of the metal building products By Marcy Marro Editor When choosing the right coatings it is important to understand the ingredients and the role they play in the overall system of the coatings There are three parts to every coating pigment resin and solvents Additives may be added to fi ne tune or improve a coatings performance characteristics Each of the three main components of paint can be modifi ed based on specifi c end use Vondran says This modifi cation process must take into consideration the application process to ensure the right adhesion formability color and gloss is created Other considerations include end use requirements cost and desired warranty coverage Many attributes of a paint are trade offs and paint mixes must be balanced to achieve certain characteristics Pigments Pigments supply the color and opacity to hide the substrate and to achieve nice even color across the entire surface There are two key types of pigments organic and inorganic Pigments are tiny particles of color that are blended according to specifi c formulations says Alexander Pigments not only add color they can also provide opacity to hide the substrate and they can improve corrosion resistance Your color selection will determine if organic or inorganic pigments or both are needed Consideration for metal panel coatings have to do with where the project is located how the sun exposure and weather elements will affect the building products and the requirement of added corrosion protection Additionally the type of color and visual effect of the coating as well as whether the desired color is part of the brand styling of the building are also important Performance considerations could include exposure to corrosion causing substances such as salt air and industrial output and heavy or inconsistent ultraviolet UV exposure says Michelle Vondran technical manager at NS BlueScope Coated Products North America Kalama Wash These factors will infl uence the Organic pigments are typically derived from plants whereas inorganic pigments are metallic compounds or oxides that are further processed to provide excellent color stability adds Vondran Organic pigments are usually brighter than inorganic pigments and can provide a cleaner or more distinctive look However organic pigments are less durable and fade faster when exposed to UV light a key consideration for exterior building design For some high visibility applications the use of a clear coat over the top of fi nishes with bright organic pigments can help reduce color fade type of paint system Integration considerations include color choice gloss levels or other fi nish options to improve the way a metal panel integrates with other building materials and the environment The advancement of coating formulations not only offers protection but a wide range of design options that include a full range of color and texture possibilities adds Alexander Further when the coating is factory applied it is more consistent more durable and more environmentally friendly than other alternatives The appeal of prepainted metal includes mechanical strength corrosion resistance and an excellent base substrate upon which to apply advanced coatings Parts of a Coating Image courtesy of Sherwin Williams Coil Coatings Resins Resins are the glue or binder that hold the coating together and impart the majority of the performance properties of the coating They provide the coatings physical and chemical attributes and determine how effectively the paint will adhere to a surface fl ex and form and weather explains Vondran The resin chemistry is also the paint type name polyester silicone polyester acrylic epoxy PVDF etc Resins hold pigments in place and protect them from damage by exposure to sunlight and rain says Kristen Blankenship business development manager at AGC Chemicals Americas 16 METAL CONSTRUCTION NEWS February 2021