Nitomortar 903: Solvent Free Epoxy Resin Binder System

Product Overview

Nitomortar 903 is a solvent-free, two-component, low viscosity epoxy resin system manufactured by Fosroc International Limited. It functions as a general-purpose epoxy binder and priming system designed for diverse concrete and steel surface preparation and repair applications.

Key Specifications

Physical Properties

Compressive Strength

Nitomortar 903 can achieve up to 90 MPa compressive strength, with the exact value depending on the mix consistency employed in the application.

Coverage Rate

Nitomortar 903 provides approximately 5-6 m²/litre when applied as a primer.

Chemical Resistance

Nitomortar 903 demonstrates excellent chemical resistance to a wide range of acids, alkalis, and industrial chemicals:

Primary Uses and Applications

Versatile Formulation Applications

Nitomortar 903 can be combined with selected fillers and aggregates to produce epoxy mortars of various consistencies. It also serves as:

• General-purpose epoxy binder for multiple applications
• Priming system for epoxy flooring products including Nitoflor systems
• Substrate primer for epoxy coatings and polyurethane systems
• Mortar base when mixed with fine aggregates for fast and permanent concrete patch repairs

Concrete and Surface Applications

The product functions as:

• Scratch coat material to smooth rough or uneven concrete surfaces prior to Nitoflor PU200 or Nitoflor FC150 HP/SL flooring application
• Primer coat on very porous concrete surfaces or to prime repair areas before application of epoxy coatings such as Nitocote EP410 and Nitocote EP405
• Repair product for concrete surface faults prior to topcoat application
• Substrate primer for preparation before application of Nitomortar 908

Mortar Consistency Options

When mixed with Nitomortar F4 Fillers in varying proportions, the product creates epoxy mortars and screeds with different consistencies:

Key Advantages

• Early development of initial hardness – minimises maintenance disruption
• Moisture-tolerant formulation – engineered to tolerate moisture conditions during application and curing
• Unaffected by aggressive chemicals – excellent resistance to a wide range of acids, alkalis, and industrial chemicals
• High compressive strength – up to 90 MPa depending on mix consistency
• Versatile mixing consistencies – adaptable for a wide range of applications and substrate conditions
• HACCP certified – suitable for use in food handling areas (Splash or Spill Zone)
• Drinking water compliance – complies with AS4020:2018 standards, suitable for use in contact with drinking water
• Solvent-free formulation – environmentally safe with low VOC content

Product Supply and Packaging

Nitomortar 903 is available in multiple pack sizes:

*MTO = Made to Order with 14-21 day lead time

Application Instructions

Surface Preparation

All grease, oil, chemical contamination, dust, laitance, and loose concrete must be removed by scabbling or light bush hammering to provide a sound substrate. While Nitomortar 903 is damp surface tolerant, it is recommended that concrete substrates be dry or at least SSD (Saturated Surface Dry) when using the product for small area repairs (up to 1 m²).

For larger epoxy and urethane flooring applications, the concrete substrate must be dry and meet the moisture content requirements of the product being applied over Nitomortar 903.

Priming Application

When applying as a general primer for roll/spray coats, apply at a rate of 6 m²/litre. If the substrate is very porous, a second coat may be required in patches or in full. Allow the primer to cure and apply the coating system within 24 hours.

Mixing as Primer

The entire contents of the hardener container should be stirred and added to the base container and mixed thoroughly for 3 minutes using a heavy-duty drill and spiral mixer, taking particular care to scrape the sides and bottom of the container.

Important: Once mixed, the product should be poured into flat, open paint trays to maximise pot life working time. Holding the product in the original mixing container will lead to an exothermic reaction, which will significantly reduce the pot life.

Cleaning

Nitomortar 903 should be removed from tools, equipment, and mixers with Fosroc Solvent 10 immediately after use.

Storage and Shelf Life

Nitomortar 903 should be stored in cool, dry conditions in original unopened packs to maintain quality. The shelf life may be reduced when stored at high temperatures and high humidity.

Standards Compliance

• HACCP certification for use in food handling areas (Splash or Spill Zone)
• AS4020:2018 compliance – suitable for use in contact with drinking water
• Certification available from Fosroc website with AWQC Report 319383

Exotherm Characteristics

All epoxy systems will develop a temperature rise on mixing. Its extent depends on the volume to surface ratio, ambient temperature, and thermal properties of surrounding materials. When using as a primer (unfilled), once mixed, place Nitomortar 903 immediately – do not hold in bulk or re-lid the container of mixed product. Do not mix more product than can be used well within the 30-minute pot life.

References

• [1] Fosroc_Nitomortar_903_TDS.pdf