403 Microfibers Adhesive Filler is a fine fiber blend. Use it to thicken epoxy blended resin/hardener and create a multi-purpose adhesive. Its most popular use is for bonding wood. Epoxy thickened with microfibers has good gap-filling qualities but will still do an excellent job of wetting-out/penetrating into wood fibers. You can blend it into any WEST SYSTEM® 105 Epoxy Resin®/200 Series Hardener combination, G/flex® 650, or G/5® Five-Minute Adhesive.
Modifying with fillers and additives makes WEST SYSTEM epoxy extremely versatile for a wide variety of bonding and coating applications. Epoxy can be thickened to the ideal consistency needed for a particular job. Epoxy thickened with adhesive (high-density) fillers strengthens structural bonds, bridges gaps, and fills voids. Epoxy thickened with fairing (low-density) fillers is easily sanded and shaped after it cures.
A fillet is a continuous bead of thickened epoxy mixture applied to the angle created between two parts. It increases the surface area of the bond and serves as a structural adhesive and brace. Because epoxy can be thickened with high-density fillers into a non-slumping consistency it can bridge large gaps in wood joints, without loss of strength, thus saving a great deal of time and labor otherwise needed to create a strong joint.