For many years surface corrosion on automotive frames was of little concern, and the approach was to spray a frame with chassis black to get it to market, since, if it rusted after it was in the customer’s hands, that was rarely noticed. In more recent times, with SUV’s and trucks in particular, more of the chassis is visible. Hence the OEMs have turned toward hot wax and even electro-coat (E-Coat) systems. The hot wax became a customer problem because, in hot weather, it would drip on the garage floor. E-coat, which provides excellent protection under intended circumstances, had been developed for sheet metal parts in addition to car and truck bodies that were zinc phosphated cold rolled steel.
It was soon discovered that the e-coat systems intended for body sheet metal did not provide similar protection on the hot rolled steel used in building a chassis. Ford went to the major paint suppliers and asked them to work on the problem. In response, PPG developed “FrameCoat.”™ FrameCoat electrocoating consists of innovative proprietary materials and processes for electrocoating frames and chassis components of cars and trucks. It is PPG's response to OEM customer requests for help in improving the durability and hence enduring appearance of hot rolled steel under-body vehicle parts. FrameCoat consists of a patented catholic epoxy electrocoat technology and an application process that satisfies GEM specifications for both cost and ten-year durability. Cost savings result from better throw distances, allowing less material usage, lower application temperatures, and the elimination of vehicle heat shields required by previous treatments such as hot wax.
FrameCoat was first introduced at Ford Motor Company on the Sport Trac frame in 1999, and is now widely used by Ford, GM, DaimlerChrysler, and their Tier 1 suppliers.