Now you can easily fill gaps or holes in wood using the West System 403 Microfibers Filler. This thickener additive contains a fine blend of fibers, and can be used for multiple purposes. The microfibers thickened with epoxy resin have good gap filling qualities.

  • Multi-purpose adhesive
  • Excellent wetting/penetrating capability
  • Good gap filling qualities

Features of West System 403 Microfibers Filler

  • Off white color

Specifications:

Manf. Part # 403-B

  • Package size: 20.0 lb

Manf. Part # 403-28

  • Package size: 20.0 oz

Manf. Part # 403-9

  • Package size: 6.0 oz

Selecting Fillers
As a rule, use higher-density fillers when bonding higher-density materials such as hardwoods and metals. Any of the adhesive fillers are suitable for most bonding situations. Your choice of a filler for general use may be based on the handling characteristics you prefer. Fillers may also be blended to create mixtures with intermediate characteristics.

Adhesive Fillers vs. Fairing Fillers
Fillers are used to thicken the basic resin/hardener mixture for specific applications. Each filler possesses a unique set of physical characteristics, but they can be generally categorized as either Adhesive (high-density) or Fairing (low-density).

Adhesive filler mixtures cure to a strong, hard-to-sand plastic useful in structural applications like bonding, filleting and hardware bonding.

Fairing filler mixtures cure to light, easily sandable material that is generally used for cosmetic or surface applications like shaping, filling or fairing.

Uses
(Resin/Hardener mixture
thickened with a Filler)		 Adhesive Fillers
Highest density
Highest strength		 Fairing Fillers
Lowest density
Easiest sanding
404 High Density 406 Colloidal Silica 403 Microfibers 405 Filleting Blend 407 Low-Density 410 Microlight
Bonding Hardware - Increased fastener interface and hardware load capability - maximum strength **** *** *** **
General Bonding - Join parts with epoxy thickened to create a structural gap filler - strength/gap filling *** *** *** ** *
Bonding with Fillets - Increase joint bonding area and create a structrual brace between parts - smoothness/strength ** **** ** *** ***
Laminating - Bond layers of wood strips, veneers, planks, sheets and cores - gap filling/strength ** *** **** ** **
Fairing - Fill low areas and voids with an easily sanded surface filler/fairing compound - sandability/gap filling *** ****

Filler Package Size Quantity of mixed epoxy required for
Ketchup Consistency Mayonnaise Consistency Peanut Butter Consistency
403-9 6.0 oz 3.8 qt 2.5 qt 1.0 qt
403-28 20.0 oz 3.2 gal 2.0 gal 0.9 gal
403-B 20.0 lb 48.0 gal 32.0 gal 15.3 gal
404-15 15.2 oz 1.2 qt 0.9 qt 0.7 qt
404-45 43.0 oz 3.6 qt 2.8 qt 2.0 qt
404-B 30.0 lb 9.4 gal 7.4 gal 5.3 gal
405 8.0 oz 0.9 qt 0.7 qt 0.6 qt
406-2 1.7 oz 1.3 qt 0.9 qt 0.5 qt
406-7 5.5 oz 1.1 gal 3.0 qt 1.7 qt
406-B 10.0 lb 27.0 gal 16.0 gal 6.0 gal
407-5 4.0 oz 0.5 qt 0.4 qt 0.3 qt
407-15 12.0 oz 1.7 qt 1.3 qt 1.0 qt
407-B 14.0 lb 6.0 gal 4.8 gal 3.7 gal
410-2 2.0 oz 1.2 qt 0.9 qt 0.7 qt
410-7 5.0 oz 3.0 qt 2.4 qt 1.8 qt
410-B 4.0 lb 8.9 gal 7.2 gal 5.6 gal