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title: Primer 21 - Fosroc
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description: Primer 21 is a single component primer used on porous surfaces with Nitoseal PU250 & Nitoseal PU400 when priming is required. Fast drying primer that enables sealant work to progress without mixing required.
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# Primer 21 - Fosroc

# Primer 21 - Fosroc

Primer 21 is a single component primer used on porous surfaces with Nitoseal PU250 & Nitoseal PU400 when priming is required. Fast drying primer that enables sealant work to progress without mixing required.

**Brand:** Fosroc

[View Product](https://www.fosroc.com.au/product/primer-21)

## Product Intelligence

# Fosroc Primer Products: Technical Details, Specifications, and Features

## Overview

Fosroc offers a comprehensive range of primer products designed as foundation systems for optimal performance in concrete repair, flooring, and protective coating applications. These primers and bonding agents ensure superior adhesion and durability across diverse construction environments.

## Primer Product Range

### Nitobond SBR

**Application:** Mortar Additive

**Key Features:**
- Water-resistant polymer formulation
- Improves strength and adhesion in repair applications
- Acts as a foundation product for optimal performance in concrete repair systems

**Primary Use Cases:**
- Enhancing concrete repair mortar performance
- Improving bonding between substrates and repair materials
- Increasing water resistance in repair systems

### Nitobond AR

**Application:** Curing Membrane

**Key Features:**
- Single-component polymer emulsion
- Provides controlled curing for concrete substrates
- Foundation product for optimal performance

**Primary Use Cases:**
- Concrete surface protection during curing
- Substrate preparation for subsequent coating applications
- Moisture control in repair and flooring systems

### Nitoprime 330

**Application:** Floor Topping Primer

**Key Features:**
- Diluted application capability for optimal bonding
- Designed specifically for floor topping systems
- Provides effective surface preparation for flooring installation

**Primary Use Cases:**
- Preparation of substrates for industrial flooring systems
- Bonding enhancement in Cemtop and Nitoflor flooring applications
- Ensuring proper adhesion between substrate and floor coating

### Nitoprime 320PU

**Application:** Polyurea Primer

**Key Features:**
- Specifically formulated for polyurea membrane applications
- Provides optimal adhesion for spray-applied polyurea systems
- Foundation product for high-performance waterproofing systems

**Primary Use Cases:**
- Substrate preparation for Polyurea WPE110 waterproofing systems
- Bonding enhancement for hybrid polyurea-polyurethane membranes (Polyurea WHE110)
- Ensuring durability of spray-applied waterproofing membranes

## Nitoprime Range as System Components

The **Nitoprime Range** serves as a critical component within Fosroc's integrated flooring and coating systems:

| Component | System Application | Function |
|-----------|-------------------|----------|
| **Nitoprime Primers** | Industrial flooring systems | First layer application ensuring proper substrate adhesion |
| **Floor Topping Layer** | Cemtop and Nitoflor systems | Middle performance layer providing durability |
| **Surface Coatings** | Nitoflor high-build coatings | Final protective layer for demanding environments |

## Technical Positioning

### Foundation Product Strategy

Fosroc's primer products are categorized as **foundation products for optimal performance**, meaning they:

- Establish proper substrate preparation
- Ensure superior adhesion between layers
- Optimize the performance of subsequent coating or topping layers
- Contribute to system durability and longevity

### Integration with Fosroc Systems

Primers are integral to complete Fosroc solutions:

- **Concrete Repair Systems:** Work with Renderoc repair mortars
- **Industrial Flooring Systems:** Support Cemtop and Nitoflor applications
- **Waterproofing Systems:** Enhance polyurea and polyurethane membrane performance
- **Protective Coating Systems:** Prepare substrates for Dekguard coatings

## Applications and Use Cases

### Industrial Flooring Applications

Primers prepare substrates in food processing facilities, warehouses, and manufacturing plants with HACCP certification where applicable.

### Concrete Repair Applications

Bonding agents enhance adhesion in structural and cosmetic repairs using the Renderoc range, ensuring long-term performance.

### Waterproofing Applications

Polyurea primers (Nitoprime 320PU) prepare surfaces for high-performance waterproofing of basements, tunnels, roofs, and foundations.

### Protective Coating Applications

Primers establish proper adhesion for Dekguard protective coatings applied to concrete and steel structures across diverse industrial environments.

## Safety and Compliance

As Fosroc products, primer formulations comply with:

- **Australian and New Zealand standards** for construction chemical applications
- **Safety protocols** with RCS (Respirable Crystalline Silica) content managed according to Fosroc's commitment to worker safety
- **Environmental compliance** through proper formulation and application guidance

## Technical Support

Fosroc provides comprehensive primer selection and application support through:

- **National Specifications Team:** Expert guidance on primer selection for specific applications
- **Account Managers:** Over 70 account managers across Australia providing on-site support
- **Training Programs:** Hands-on product application training for primers and integrated systems
- **On-Site Assessment:** Representatives assess substrate conditions and recommend optimal primer selection

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### References

- [1] Fosroc Australia Business Profile and Product Documentation