Photo from UnsplashOriginally Posted On: https://www.mudgefasteners.com/news/2021/11/28/are-dura-con-or-molykote-fasteners-better-for-solar-installations
Because PV solar arrays are exposed to harsh weather conditions, the fasteners included in their mounting systems should always have a high level of corrosion resistance. While many engineers choose standard stainless steel fasteners due to their longstanding reputation for corrosion resistance, there are actually better options.
DURA-CON and Molykote are newer proprietary coatings marketed for use in solar panels installations and other outdoor environments. Both of these coating claims to have both corrosion resistant properties and properties meant to decrease the friction coefficient of the assembly to reduce the possibility of galling.
While there is limited independent test data for Molykote fasteners, DURA-CON Corrosion Resistant Fasteners have been specifically tested in aluminum solar panel racking materials, withstanding 1500 hours of Salt Spray per ASTM B-117 with zero corrosion.
DURA-CON Fasteners employ a three layer coating system that consists of an inorganic zinc-rich first coat and an aluminum-rich organic second coat. Friction modifiers are integrated into the topcoat, resulting in repeatable torque tension characteristics during assembly. Molykote fasteners are said to have a “paint-like” solution applied to them to reduce friction, but without supporting test data.
Additionally, the proprietary DURA-CON coating allows for use of Grade 5 bolts, which are stronger than A307 zinc, hot dip galvanized or 300 series stainless steel bolts. All of this adds up to a finished product that is high strength, with high corrosion resistance, and no galling.
