West System 404 High Density FillerThis high density filler by West System is designed to act as an epoxy thickening agent. Created for maximum adhesion properties in hardware bonding where high-cyclic loads are anticipated. Also useful for filleting or gap filling with epoxy where maximum strength is needed. Excellent at bonding hardware with epoxy to increase the maximum strength and load capacity. Excellent strong and structural gap filler. Available in an off white color. West System's 404 High Density filler is recommended as the easiest to use filler for hardware and stud bonding while being very cost effective. Just small amounts of the high density filler can help reduce creep in epoxy. A moderately loose slurry, where the epoxy is thick enough to stay in a horizontal hole without overfilling, is recommended. To much of the 404 can result in air entrapment. Chopped glass or carbon fiber can be used to increase the load carrying capability, but does add additional coast and difficulty. The 404 boats a ,conservative, shear strength of 800 psi for the 105 Resin, 206 Slow hardener, and 404 High Density Filler mix. The typical failure initiation point is between the fastener threads and epoxy. The fatigue failure mechanism for epoxy, gradual destruction of the matrix and cracking, give some warning of when repairs are needed. Factors that can influence the shear strength of the epoxy include the type of wood used, type of fasteners, material of fasteners, and hole size. Click here to download 404 High Density Filler Safety Data Sheet