Description & Features
Cab-O-Sil® Epoxy Thickener is a lightweight fumed silica additive that increases the viscosity of epoxy, polyester, and vinyl ester resins without adding significant weight. It creates smooth, non-sag mixtures that are easier to apply for bonding, filleting, filling, and vertical surface repairs.
By adjusting the amount added, you can customize resin consistency from a slightly thickened liquid to a heavy, peanut butter-like adhesive. Cab-O-Sil is chemically inert, moisture resistant, and will not affect the curing characteristics of properly mixed resin systems.
Often combined with fiberglass or milled fibers, Cab-O-Sil helps create high-strength structural repair compounds for marine, automotive, aerospace, and composite fabrication projects.
Key Features
- Lightweight fumed silica thickening additive
- Creates smooth, non-sag resin mixtures
- Compatible with epoxy, polyester, vinyl ester resin, and gelcoat
- Ideal for bonding, filleting, gap filling, and structural repairs
- Adjustable viscosity for a wide range of applications
- Can be combined with reinforcing fibers for added strength
- Moisture resistant and chemically inert
Specifications
- Manufacturer: Fiberglass Supply Depot
- Material: High-purity fumed silica
- Container Size: 8 fl oz
- Container Dimensions: 4.5 in. diameter × 1.75 in. tall
- Compatible With: Epoxy, polyester resin, vinyl ester resin, gelcoat, adhesives, and fairing compounds
Best Use
Perfect for fiberglass repair, boat building, composite fabrication, mold construction, structural bonding, corner fillets, gap filling, and custom adhesive formulations where controlled resin thickness is required.
Materials & Construction
Cab-O-Sil® is manufactured from ultra-fine fumed silica particles that disperse throughout resin to increase viscosity while maintaining low weight. It allows precise control over resin flow and helps prevent sagging on vertical or overhead applications.
Handling Note: Cab-O-Sil is an extremely fine powder that becomes airborne easily. Wear appropriate respiratory and eye protection, and add the powder slowly while mixing to minimize dust.
Common Applications
- Marine fiberglass repair
- Boat building
- Composite fabrication
- Structural adhesive mixtures
- Fillets and corner radiusing
- Gap filling
- Fairing compounds and putties
- Vertical and overhead laminating
