Nitomortar EL-HB: Epoxy Repair Mortar System

Product Overview

Nitomortar EL-HB is a high-performance, three-component epoxy repair mortar system manufactured by Fosroc International Limited. It is specifically engineered as a hand-applied, trowel-finished, high-build epoxy repair mortar consisting of solvent-free epoxy resins combined with chemical-resistant fillers. The product is designed for permanent repairs to concrete structures and similar substrates where superior chemical and physical bonding is essential.

Key Characteristics

Composition and Form

Nitomortar EL-HB is supplied as a three-component system in 9-litre packs, with components proportioned to facilitate easy on-site mixing. The system comprises:

• Part A (Base): Epoxy resin (1.77L)
• Part B (Hardener): Hardener component (920ML)
• Part C (Fillers): Chemical-resistant fillers (10.4KG)

When properly mixed, the material achieves a thixotropic consistency ideal for hand placement, with easy trowel finishing for smooth surface completion.

Primary Applications

The product is particularly suited for:

• Patch repairs to concrete structures, including manholes and sewers
• Overhead, vertical, and horizontal patching and resurfacing applications
• Small pocket-type substrate repairs with application window within 90 minutes at 20°C
• Repairs requiring thicknesses greater than those achievable with Nitomortar 908

The product is not designed for application to large areas and excels in targeted, localized concrete rehabilitation.

Performance Properties

Mechanical Strength

Nitomortar EL-HB demonstrates exceptional mechanical performance:

• Compressive strength: Greater than 45 MPa at 7 days (at 20°C)
• Strengths exceed those of the concrete to which the material is applied
• Excellent resistance to abrasion and impact
• Initial hardness: 4 hours at 20°C
• Full cure: 7 days at 20°C

Chemical Resistance

The product exhibits unmatched chemical resistance to a comprehensive range of substances, including:

• Bleach, detergents, and cleaning agents — Excellent performance
• Acids: Sulphuric acid (25%), Nitric acid (25%), Phosphoric acid (25%), and Hydrochloric acid (25%) — All rated Excellent
• Alkalis: Sodium hydroxide (25%) — Excellent performance
• Fuel and solvents: Diesel fuel, petrol, toluene, and kerosene (100%) — All rated Excellent

This broad chemical resistance makes Nitomortar EL-HB ideal for industrial environments where chemical spillage is a concern.

Environmental Durability

• Unaffected by freeze-thaw attack, eliminating problems encountered with conventional water-based materials
• Cured material provides long-lasting waterproof barrier
• No harmful vapours present during application or curing
• Low odour and non-sag properties enhance workability and safety

Application Parameters

Design Criteria for Thickness

The product accommodates varying repair geometries:

• Horizontal locations: Up to 100mm thickness in single applications
• Vertical locations: Built-up to maximum 30mm thickness
• Minimum thickness: 5mm (below this thickness, application is not recommended)
• Greater thicknesses: Achievable through application of subsequent layers

Temperature and Environmental Requirements

• Minimum application temperature: 5°C
• Suitable for application on both dry and damp (SSD - Saturated Surface Dry) surfaces
• Superior chemical and physical bond achieved on dry substrates
• Application window: 90 minutes at 20°C after Nitobond EP primer application (while primer remains tacky)

Mixing and Pot Life

• Pot life: 45 minutes at 20°C
• Mixing method: Slow-speed electric drill with suitable paddle
• Mix process: Approximately 5 minutes continuous mixing until uniform gel-like consistency is achieved
• Part packs: Should never be mixed in partial quantities due to risk of incorrect proportioning

Application Procedure

Surface Preparation

1. Clean surfaces of dust, unsound material, plaster, oil, paint, grease, corrosion deposits, and algae
2. Roughen surface and remove laitance by light scabbling or grit-blasting
3. Saw cut or cut back extremities of repair locations to minimum 5mm depth, avoiding feather-edging
4. Break out complete repair area to minimum 5mm depth
5. Stop active hydrostatic leaks using Vandex Plug before Nitomortar EL-HB application

Priming System

• Nitobond EP primer must be applied to all prepared surfaces immediately after mixing
• Application method: Brush applied to prepared surfaces
• Coverage: 4–5 m²/litre
• Primer condition: Must remain tacky during Nitomortar EL-HB application
• Substrate tolerance: Primer can be applied on dry or damp (SSD) substrates

Material Application

• Apply Nitomortar EL-HB with gloved hand within 90 minutes of primer application
• Work material firmly into substrate surface
• Build up to desired substrate level
• Finish with steel trowel
• Surface closure: Lubricate trowel with water for smooth finish
• Do not thin components as solvents will prevent proper cure

Coverage and Yield

Each 9-litre pack of Nitomortar EL-HB provides:

• Theoretical coverage: Approximately 0.9m² at 10mm thickness
• Practical coverage: Reduced from theoretical figures due to wastage factors and substrate variability

Nitobond EP primer coverage: 4–5 m²/litre

Storage and Shelf Life

• Shelf life: 5 years when stored in cool, dry conditions in original, unopened packs
• Storage conditions: Must be maintained in original packaging
• Temperature sensitivity: Shelf life may be reduced if stored at high temperatures and/or high humidity
• Handling: Never attempt to mix part packs

Important Limitations

• Not suitable for application when temperature is below 5°C and falling
• Small pocket repairs only: Product designed specifically for localized repairs, not large-area applications
• Build volume dependent: On repair size and geometry
• Part pack mixing prohibited: Incorrect proportioning severely affects cured properties

Technical Documentation and Safety

• Safety Data Sheet (SDS): Available from Fosroc website and must be read before use
• Technical Data Sheet (TDS): Contains comprehensive product information and usage guidelines
• Emergency contact: Poisons Information Centre (phone 13 11 26 within Australia)

Cleaning and Maintenance

Nitomortar EL-HB and Nitobond EP should be removed from tools, equipment, and mixers using:

• Water (preferred method)
• Fosroc Solvent 10 (alternative solvent)
• Immediate application: All cleaning must occur immediately after use

Product Designation and Distribution

Nitomortar EL-HB is manufactured and sold under license from Fosroc International Limited. The product is distributed in Australia by Parchem Construction Supplies Pty Ltd (ABN 80 069 961 968) and in New Zealand through authorized distributors. Fosroc, Nitomortar, and the Fosroc logo are registered trademarks of Fosroc International Limited, used under license.

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References

• [1] Fosroc_Nitomortar_903_TDS.pdf
• [2] Fosroc_Nitomortar_EL-HB_TDS.pdf
• [3] Fosroc_Nitomortar_908_TDS.pdf
• [6] Fosroc_Nitobond_EP_TDS.pdf