Nitoseal PY350: Hybrid Polyurea Joint Sealant

Product Overview

Nitoseal PY350 is a two-component hybrid polyurea, elastomeric rapid cure joint sealant designed for sealing low movement and saw cut joints in concrete floors. Manufactured by Fosroc, this product is supplied in dual 300ml cartridges (600ml total) or 40 litre kits for industrial and commercial applications requiring high performance joint sealing.

Primary Applications

Nitoseal PY350 is specifically designed for:

• Sealing low movement and saw cut joints in concrete floors where high Shore A hardness is required
• Retail, warehousing, and industrial facilities including bunds and similar structures
• Heavy hard wheeled traffic applications where abrasion resistance is critical
• Repair of spalled joints and random crack repair in concrete floors

Key Advantages

• Very fast curing – Quick return to service time (2 hours full cure at 25°C)
• High Shore A hardness (80 ±3) – Provides tough, durable sealing
• Tough and abrasion resistant – Seals and protects joint edges from wear
• Chemical resistant – Demonstrates excellent resistance to a wide range of chemicals
• Weather resistant – Suitable for both internal and external applications
• Aliphatic formulation – Provides UV resistance and colour stability
• Chemical cure – Independent of ambient humidity and joint size
• Easy application – Simple to gun out and tool to finish

Design Specifications

Movement Accommodation

Nitoseal PY350 should only be used in very low movement construction/contraction joints where anticipated movement is less than 5% of the joint width.

Movement accommodation factor: +5% / -5% (10% total)

Joint Width and Depth Design

Joints should be sealed with width-to-depth ratios as follows:

Joint Width	Depth Requirement
6 to 12mm wide	Depth equal to width (1:1)
13 to 24mm wide	12mm depth
Over 25mm wide	Depth is half the width (2:1)

Important: Joints should only be sealed after initial shrinkage has occurred in new concrete, typically after 90 days.

Product Form and Properties

Property	Specification
Form	Non-slump thixotropic paste
Colour	Grey
VOC Content	<1g/litre (ASTM D2369)
Mix Ratio	1:1 by weight or volume
Density (cured)	1.05 g/cm³
Hardness	80 (±3) Shore A (ASTM D2240)
Tensile Strength	17 MPa (ASTM D412)
100% Modulus	3.1 MPa (ASTM D412)
300% Modulus	5.3 MPa (ASTM D412)
Elongation at Break	780% (ASTM D2240)
Angle Tear Strength	54 kN/m (Die C) (ASTM D624)
DIN Resiliency	41% (ASTM D1817)

Curing and Service Characteristics

Cure Timeline

Timeline	Specification
Tooling Time	4 minutes @ 25°C
Shave/Trim Time	30 to 50 minutes @ 25°C
Tack-Free Time	75 minutes @ 25°C
Light Traffic	90 minutes @ 25°C
Full Cure	2 hours @ 25°C

Temperature Range

• Application Temperature: Minimum 5°C (joint must be dry and frost free)
• Service Temperature: -20°C to +80°C
• Physical/Chemical Change: Chemical cure (non-acidic)

Chemical Resistance

Excellent Resistance (Little or No Effect)

Nitoseal PY350 demonstrates excellent chemical resistance to:

• Ammonium Hydroxide
• Boric Acid
• Calcium Chloride
• Calcium Hydroxide
• Castor Oil
• Glycerine (Glycerol)
• Greases
• Hexane
• Mineral Oil
• Petroleum
• Tartaric Acid
• Vegetable Oil

Good Resistance (Minor to Moderate Effect)

• Ammonia
• Animal Fats
• Benzoic Acid
• Butyl Alcohol
• Chlorine
• Citric Acid
• Cyclohexane
• Ethylene Glycol
• Ferric Chloride
• Hydrochloric Acid (20%)
• Hydrofluoric Acid
• Hydrogen Peroxide
• Isopropyl Alcohol
• Sodium Dichromate
• Sodium Hydroxide (45%)
• Sodium Nitrate
• Transformer Oil
• Trisodium Phosphate
• Urea
• Zinc Chloride

Fair Resistance (Moderate to Severe Effect)

• Acetic Acid
• Ammonium Acetate
• Chromic Acid
• Ethyl Alcohol
• Ethyl Bromide
• Ethyl Chloride
• Hydrogen Sulphide
• Phosphoric Acid (Concentrated)
• Turpentine
• Xylene

Poor Resistance (Not Recommended)

• Acetone
• Benzene
• Butyl Acetate
• Ethyl Acetate
• Methyl Alcohol
• Methyl Ethyl Ketone
• Methyl Chloride
• Nitric Acid
• Skydrol Oil
• Sodium Hypochlorite (5%)
• Steam
• Toluene
• Trichloroethylene

Application Instructions

Surface Preparation

• Joint faces must be sound and completely dry, clean, and frost free
• Remove all oil, grease, curing compounds, form release agents, and surface contaminants by grinding joint faces
• Bond breaker required in all joints to prevent sealant contact with the back of the joint
• Deep joints should incorporate a backing strip such as Expandafoam or Hydrocell to support the sealant while acting as a bond breaker

Priming

• Priming of well-prepared concrete joints is normally not required
• For optimum results, particularly with moving joints, priming with Fosroc Primer 13 should be considered
• Primer 13 must be thoroughly mixed before applying and must be touch dry before applying sealant

Application Method

1. Fit the 600ml dual cartridges into Fosroc Polyurea WCS Manual Gun (FC007087-UNIT)
2. Attach the Nitoseal PY350 Static Mixer nozzle (FC920126-UNIT)
3. For 40kg kits, use a Graco E10 pump with an appropriate gun fitted with the Static Mixer nozzle
4. Gun out a small quantity of mixed product to waste to ensure sufficient mixing in the static mixer
5. Immediately begin gunning the mixed product into the prepared joint
6. Ensure sealant is forced well against all joint surfaces for optimum adhesion
7. Guide nozzle along the joint gradually with even pressure on the trigger
8. Slightly over-fill the joint; trim excess after 30-50 minutes @ 25°C for a flat, even finish

Tooling

• Any tooling must be completed immediately after application before the sealant sets (approximately 1 minute)
• Do not use soapy water as a tooling aid, as it may adversely affect sealant cure

Cleaning

• Equipment should be cleaned promptly using Fosroc Solvent 10
• Cured sealant is very difficult to remove and can only be removed by mechanical methods

Limitations and Restrictions

• Not suitable for expansion joints in concrete due to limited movement accommodation
• Should not be applied in close proximity to bituminous materials or products containing reclaimed rubber (e.g., some tile adhesives)
• If doubt exists regarding compatibility, contact Fosroc for technical advice

Coverage

As a guide, each 600ml pack of Nitoseal PY350 will seal 4.2 metres of a 12mm wide × 12mm deep joint.

Each 40kg pack will yield approximately 38 litres of mixed product.

Supply Options

Standard Product

• Nitoseal PY350 Grey 600ml: FC920125-600ML
• Supplied in dual 300ml cartridges in cartons of 10

Made-to-Order Kits

• Minimum order: 20 kits
• Lead time: 14-21 days
• Nitoseal PY350 Part A 20kg: FC920123-20KG
• Nitoseal PY350 Part B 20kg: FC920124-20KG

Ancillary Products

Product	Product Code
Fosroc Polyurea WCS Manual Gun	FC007087-UNIT
Nitoseal PY350 Static Mixer	FC920126-UNIT
Primer 13 (250ml pack) Base	FC965229-125ML
Primer 13 (250ml pack) Hardener	FC965230-125ML
Primer 13 (1 litre pack MTO) Base	FC965229-500ML
Primer 13 (1 litre pack MTO) Hardener	FC965230-500ML

Storage and Shelf Life

• Shelf life: 12 months in unopened containers
• Storage conditions: Cool, dry conditions
• Keep containers unopened to maintain product quality

Standards Compliance

Nitoseal PY350 has been tested and is referenced in technical documentation with compliance to applicable standards for joint sealant performance.

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References

• [1] Fosroc_Nitoseal_PY350_TDS.pdf