Fillers are powdered materials added to an epoxy system to impart specific and desired physical characteristics depending upon the application used for the system. While each particular filler possesses its own unique set of physical attributes, their use in an epoxy system can be loosely placed into two general categories. High-density fillers are used in the manufacture of strong but hard to sand systems that are used mostly in structural applications like bonding, adhesion and reinforcement. Low-density fillers are used in light and easily sanded epoxy systems that are applied where it must be shaped, filled or faired because of cosmetic concerned.
