West Systems 403B Microfibers Epoxy Thickening Additive 20 lb

West System 403B Microfibers is a fine fiber blend designed as a thickening additive for epoxy resin systems. This off-white filler builds volume quickly and blends easily to create versatile adhesive compounds, making it especially effective for bonding wood and other porous materials.

Key Features:

• Fine fiber blend that mixes smoothly into epoxy resins without clumping
• Excellent gap-filling properties for joints and uneven surfaces
• Maintains superior wetting characteristics for strong penetration into wood grain
• Creates a high-strength structural adhesive when mixed with epoxy
• Multi-purpose additive suitable for laminating, filleting, and bonding applications
• 20 lb container provides substantial volume for large projects or professional use

When added to West System epoxy resins, 403 Microfibers create a strong, easily worked paste that's ideal for filleting, bonding, and filling voids. The fiber blend maintains the epoxy's ability to wet out surfaces while adding body and reducing sag on vertical surfaces. This additive is particularly valued in marine applications, woodworking, and composite fabrication where strong structural bonds are critical.