West System 403 Microfibers Adhesive Filler

The WEST SYSTEM 403 Microfibers Adhesive Filler is a high-strength epoxy thickening additive, ideal for boat building, yacht repairs, woodworking and structural bonding.

Made from fine cellulose microfibers, it transforms epoxy resin into a strong adhesive with excellent gap-filling properties and penetration into wood fibers.

Perfect for bonding timber, marine plywood, fiberglass (GRP) and composite materials, it provides durable, reliable joints for demanding marine applications.

Technical Specifications

• Brand: WEST SYSTEM
• Product: 403 Microfibers Adhesive Filler
• Type: Epoxy Adhesive Thickening Additive
• Material: Fine Cellulose Microfibers
• Colour: Off-White
• Applications: Wood Bonding, Laminating, Gap Filling and Marine Repairs
• Compatibility: WEST SYSTEM 105 Resin with 200 Series Hardeners, G/flex 650 and G/5 Adhesive
• Mixing Ratio: Approximately 4–16% by weight
• Listed Package Sizes: 150g, 750g and 800g

Mixing Instructions

Mix WEST SYSTEM 105 Epoxy Resin with the appropriate hardener before gradually adding the 403 Microfibers.

Recommended filler addition:

• 4% by weight: Flowable consistency.
• 7% by weight: Medium consistency for general bonding.
• 16% by weight: Thick consistency for gap filling.

Percentages refer to the weight of the already mixed epoxy resin and hardener.