Epoxite-EPG 103/ EH 301

Tooling & Casting Grade

Resin: EPG 103 | Hardener: EH 301
Mix Ratio (w/w): 100:10
System Type: Heavy-duty epoxy formulation for mold backing, core filling, and structural repair

Product Overview

Epoxite® 103/301 is a high-performance, ambient-cure epoxy system engineered for industrial tooling, mold building, and structural backfilling. Comprising EPG 103 (resin) and EH 301 (hardener), this system is optimized for strength, stability, and machinability. Adding fillers is strongly recommended for most structural and gap-filling applications.

Key Features

• Strong bonding to metal, composites, wood, and concrete

• Excellent dimensional stability and compressive strength

• Machinable and sandable after cure

• Suitable for vertical or overhead use when filled

• Long working time for ease of application

• High resistance to shrinkage and thermal distortion
  
  

Technical Specifications 

Resin – EPG 103

• Appearance: Clear to pale yellow liquid

• Viscosity @ 25°C: 1300 – 1700 mPas

• Epoxy Equivalent Weight (EEW): 182 – 190 g/eq

• Density @ 25°C: 1.10 – 1.15 g/cm³

• Colour (Gardner): Max 2

Hardener – EH 301

• Appearance: Clear to pale yellow liquid

• Viscosity @ 25°C: 5 – 20 mPas

• Amine Value: 430 – 460 mg KOH/g

• Density @ 25°C: 0.94 – 0.98 g/cm³

• Colour (Gardner): Max 2
  
  

Mixed System (without filler)

• Mix Ratio (by weight): 100:10 (Resin:Hardener)

• Initial Mix Viscosity: 600 – 800 mPas

• Glass Transition Temperature (Tg): 70 – 80°C (post cure)

• Shore D Hardness (after full cure): ~85

• Water Absorption (24h @ 25°C): < 0.25%

• Compressive Strength: ~80–90 MPa

• Tensile Strength: ~45–50 MPa

Typical Applications

• FRP mold backing and reinforcement

• Casting of jigs, cores, and tool templates

• Repair of fibreglass/carbon composite structures

• Structural backfilling and panel work in marine and industrial use

• Build-up of router beds, assembly blocks, and base plates

Mix Ratio (by weight)

• Resin (EPG 103): 100 parts

• Hardener (EH 301): 10 parts

• Fillers (recommended): 50–150 parts (based on desired consistency)

How Much Filler to Use?

• For heavy backfilling or casting
  Use 100–150 parts filler per 100 parts resin. This gives a thicker paste for mold filling and core build-ups.

• For patching, bonding or moderate viscosity
  Use 50–80 parts filler for a spreadable but non-sag mix.

• For machinable, lightweight casting
  Blend Calcium Carbonate + Glass Microspheres (e.g., 70:30 ratio).

Filler Quantity Guide for Epoxite 103 Resin (Per 1 Litre / 1120g)

• Low Filler Load – 50 phr (parts per hundred resin)
  - Add 560 g of filler to 1120 g resin
  - Estimated Viscosity @25°C : ~1500 – 3000 mPas
  - Result: Thicker liquid or semi-flowing mix (for light filling or casting)

• Standard Paste – 100 phr
  - Add 1120 g of filler to 1120 g resin
  - Estimated Viscosity @25°C : ~5000 – 10,000 mPas
  - Ideal for mold backing, gap-filling, and panel repairs 
  - Result: Balanced paste with spreadable consistency

• Heavy Body Paste – 150 phr
  - Add 1680 g of filler to 1120 g resin
  - Estimated Viscosity @25°C : 10,000 – 50,000+ mPas
  - Suitable for trowel application and thick core build-ups
  - Result: Non-sag, putty-like texture for vertical or overhead application

Filler Options & Their Functions

1. Alumina Trihydrate (ATH) – Improves flame resistance and density

2. Calcium Carbonate – Adds bulk and structural body cost-effectively

3. Fumed Silica (Aerosil 200 or 400) – Increases thixotropy and sag resistance

4. Glass Microspheres (optional) – Reduces weight and improves machinability

Processing & Application Guidelines

• Mix fillers into resin first until desired consistency is reached

• Add EH 301 hardener only after filler is fully dispersed

• Use metal spatula or mechanical stirrer for uniform blending

• Recommended layer thickness: 10–15 mm per application

• Pot life: 30–60 minutes at 25°C

• Curing schedule:

  • 25°C: 12–14 hours

  • 40°C: 5–7 hours

  • 60°C: 2–3 hours

• For large castings or thick sections, apply in stages to reduce exotherm

Packaging Options

• Pre-filled 1.1 kg kits (Resin + Hardener + Fillers – lab prepared)

• Bulk packs in pails or cartridge systems for industrial use

• Custom kits available on request for high-volume users

Storage & Shelf Life

• Store between 20°C and 30°C in dry, sealed containers

• Avoid moisture contact — always reseal tightly after use

• Shelf life:

  • Unfilled system: Up to 2 years

  • Pre-filled paste kits: 6–9 months (depending on filler type and moisture control)

Safety & Handling

• Always wear gloves, goggles, and protective clothing during handling

• Use in a well-ventilated area

• In case of skin contact, wash with soap and water