406 COLLOIDAL SILICA

What is WEST SYSTEM 406 Colloidal Silica and why choose it?

WEST SYSTEM 406 Colloidal Silica is a high-density, synthetic amorphous silica powder used as a thickening additive for epoxy systems. When blended into WEST SYSTEM epoxy resin and hardener, it increases viscosity to create a smooth, non-sagging mixture that is ideal for structural bonding, fillets and overhead or vertical applications. It is one of the most versatile and widely used adhesive fillers in the WEST SYSTEM range, combining high strength with a smooth, easy-to-apply texture.

Main features

• High-strength adhesive filler: Designed to produce strong, high-density epoxy mixtures suitable for structural bonding.
• Excellent thickening effect: Controls epoxy viscosity to prevent runoff on vertical and overhead surfaces.
• Smooth, creamy texture: Creates a non-slumping, smooth mix for clean fillets and neat bonding lines.
• Very versatile: Suitable for general bonding, filleting, gap filling and reinforcing other fairing fillers to improve strength and abrasion resistance.
• Off-white color in mix: Produces an off-white epoxy mixture and cured surface, easy to coat or fair over.
• Compatible within WEST SYSTEM range: Can be blended into WEST SYSTEM 105 Resin/200 Series Hardeners, G/flex 650 and G/5 Five-Minute Adhesive (information based on manufacturer data).
• Fine powder, low odor: White, odorless powder that disperses well when mixed correctly with liquid epoxy.

Technical specifications

• Chemical family: Synthetic amorphous pyrogenic silica.
• Physical form: Solid powder.
• Appearance: White powder; epoxy mixtures cure to off-white.
• Odor: None / odorless.
• Relative density (silica): Approx. 2.2 (water = 1).
• Water solubility: Only slightly soluble.
• Main ingredient: Synthetic amorphous pyrogenic silica (CAS 112945-52-5, 80–100%).
• Typical product sizes (manufacturer): 406-2 (approx. 1.7 oz), 406-7 (approx. 5.5 oz), 406-B (approx. 10 lb).
• Intended use: Thickening agent for liquid epoxy resins.

Some numerical values (for example mixing ratios with specific epoxies in volume or weight percent) are not detailed here and should be verified directly in the official WEST SYSTEM technical data.

Applications and use cases

General bonding and gap filling

• Thickens liquid epoxy into a structural adhesive suitable for wood, composites and many construction materials (compatibility with specific substrates should be verified in each project).
• Bridges gaps and fills voids while maintaining high bond strength.

Fillets and corner reinforcements

• Ideal for creating smooth, strong fillets along internal corners in boatbuilding, composite structures and woodworking.
• The non-slumping consistency helps maintain fillet shape until cure.

Vertical and overhead work

• Reduces or eliminates sagging of epoxy in joints above head height or on vertical surfaces.
• Useful for bonding hardware or structural elements where the adhesive must stay in place during assembly and cure.

Reinforcing fairing mixtures

• Can be combined with low-density fairing fillers to increase toughness and abrasion resistance of the cured surface.
• Helps obtain a smoother, stronger surface in high-wear areas.

Typical sectors

• Boatbuilding and marine repair.
• Composite fabrication and laminating workshops.
• Woodworking, furniture and joinery with structural epoxy joints.
• General maintenance, repair and construction where strong epoxy bonds are required.

All application examples above are based on typical uses described by the manufacturer; specific performance in any given project must be verified with tests and by consulting official WEST SYSTEM documentation.

FAQ – WEST SYSTEM 406 Colloidal Silica

1. What is WEST SYSTEM 406 Colloidal Silica used for?

It is used as a thickening additive for epoxy. When mixed into epoxy resin and hardener, it increases viscosity to create a high-strength adhesive suitable for bonding, fillets, gap filling and vertical or overhead joints.

2. How is 406 Colloidal Silica mixed with epoxy?

First blend the epoxy resin and hardener according to the epoxy manufacturer’s instructions. Then gradually add small amounts of 406 while stirring until the desired consistency (from slightly thickened to non-slumping paste) is reached. Exact addition levels depend on the job and should be confirmed in WEST SYSTEM guides or technical data. This information is not fully specified here.

3. Can it be used with any epoxy system?

It is specifically designed and recommended for WEST SYSTEM epoxies. Use with other epoxy brands may be possible but is not verified in this description; always run compatibility tests and consult the relevant epoxy manufacturer before use.

4. What color does the mixture cure to?

The mixture cures to an off-white color, which can be coated, painted or faired over once fully cured.

5. Is 406 Colloidal Silica classified as hazardous?

According to the current WEST SYSTEM Safety Data Sheet, this product is not classified as hazardous under the referenced regulations. However, the powder can cause mechanical irritation if excessive dust is generated, so recommended handling and personal protective measures must still be followed.

6. How should I store the product?

Store in a cool, dry place in tightly closed containers to prevent moisture uptake and contamination. The Safety Data Sheet indicates a recommended storage temperature between approximately -17 °C and 38 °C. Avoid conditions that generate airborne dust. For the latest details, always check the official SDS.

7. Does the filler have a shelf life?

The Safety Data Sheet does not specify a fixed shelf life. As a mineral powder, it is generally stable if kept dry and uncontaminated. Nevertheless, long-term storage recommendations are not fully verified here; consult the current WEST SYSTEM documentation or packaging for any stated shelf life.

8. Can I sand the cured mixture easily?

Epoxy mixtures thickened with high-density adhesive fillers like 406 are typically strong and harder to sand than low-density fairing fillers. This characteristic is implied by the manufacturer’s filler selection guides but the exact sanding behavior depends on mixture proportions and is not quantified in this description.

9. Is 406 Colloidal Silica suitable for underwater or marine applications?

It is widely used in marine construction and repair when combined with WEST SYSTEM marine epoxies. Resistance to continuous immersion or specific service conditions, however, must be confirmed in each project using official WEST SYSTEM guidelines and appropriate testing.

Section 14 – Transport information

The following summary is based on the current WEST SYSTEM Safety Data Sheet for 406 Colloidal Silica. It is provided for general information only and does not replace official transport documentation.

• US DOT (ground transport, United States): Not regulated as a dangerous good. No UN number, hazard class, packing group or specific shipping name are assigned.
• Canada TDG: Not regulated as a dangerous good. No UN number, hazard class, packing group or specific shipping name are assigned.
• ICAO / IATA (air transport): Not regulated as a dangerous good. No UN number, hazard class, packing group or specific shipping name are assigned.
• IMDG (sea transport): Not regulated as a dangerous good. No UN number, hazard class, packing group or specific shipping name are assigned.
• Marine pollutant: Not classified as a marine pollutant in the referenced SDS.

Even though it is not classified as a dangerous good for transport under these systems, normal precautions for handling industrial powders still apply. Always check the latest official Safety Data Sheet and relevant national or international transport regulations before shipment, as classifications and rules may be updated over time.

Section 8 – Individual protection measures

This section summarizes the personal protective measures recommended in the current Safety Data Sheet for WEST SYSTEM 406 Colloidal Silica. It is intended as a guide for typical occupational settings and does not replace a site-specific risk assessment or regulatory requirements.

Engineering controls

• Use with adequate general ventilation and/or local exhaust ventilation to keep airborne dust levels below applicable occupational exposure limits.
• Design handling and mixing operations to minimize dust generation (for example, careful pouring and enclosed or locally exhausted transfer points).

Eye and face protection

• Wear safety glasses with side shields as a minimum.
• Use chemical splash goggles if there is a higher risk of dust or particles entering the eyes.

Skin protection

• Wear suitable work clothing that minimizes direct skin contact with the powder.
• The SDS notes that gloves or a barrier cream may help prevent skin from drying or becoming slightly irritated.

Respiratory protection

• If ventilation is not sufficient to keep airborne concentrations below established limits, use a NIOSH-approved particulate respirator (for example, at least an N95 filter, or higher efficiency as required by workplace conditions and local standards).
• Selection and use of respirators must follow applicable regulations (such as OSHA 29 CFR 1910.134 in the United States or equivalent national standards) and be based on a proper assessment of exposure and ingredients.

Additional hygiene measures

• Avoid breathing dust and avoid creating dust clouds (for example, by using compressed air for cleaning).
• Wash hands and any exposed skin thoroughly after handling and before breaks or meals.
• Prevent contact with eyes and prolonged or repeated contact with skin.
• Work cleanly and store the product in closed containers to reduce dust and contamination.

Occupational exposure limits (summary)

• The SDS references occupational exposure limits for amorphous silica and "particulates not otherwise specified" (PNOS), such as OSHA and ACGIH threshold limit values.
• Exact numerical values and regulatory frameworks can vary by country and are not fully detailed here; always consult the full official Safety Data Sheet and applicable local regulations for current limits.

Users must integrate these recommendations into their own health and safety management system and verify them against local legislation and the most recent WEST SYSTEM Safety Data Sheet.

*Contenido generado por IA