Sikaflex®-298 | Lightweight Thixotropic Polyurethane Adhesive for Marine Teak Decking (IMO Compliant)

In marine projects, the durability, comfort, and long-term performance of deck coverings are directly related to the quality of the adhesive used. Sikaflex®-298 is a professional-grade solution for teak deck installation, offering reliable performance with its moisture-curing, one-component polyurethane formulation and lightweight thixotropic structure. The product complies with International Maritime Organization (IMO) requirements.

Product Description

Sikaflex®-298 is an elastic polyurethane adhesive specially developed for marine applications. It features a long open time, making it suitable for large-area teak deck installations where extended working time is required.

Thanks to its sound-damping properties, it helps reduce noise caused by vibration and impact. It provides reliable bonding performance even under high temperature and humidity conditions.

The low-odor formulation does not contain highly flammable solvents, providing additional safety advantages, especially in enclosed boat applications.

Application Areas

Sikaflex®-298 is commonly used for:

• Bonding teak deck coverings
• Installation of teak panels on sub-deck surfaces
• Bonding synthetic resin-based deck coverings (excluding PE and PP surfaces)

Suitable Substrates:

• GRP (Glass Reinforced Plastic)
• Marine plywood
• Steel
• Epoxy or PU-acrylic coated aluminum
• Stainless steel

Note: Compared with Sikaflex®-298 FC, Sikaflex®-298 offers a longer open time. This provides advantages in applications where high temperatures and/or high humidity conditions are expected. Professional application is recommended, and preliminary testing under actual site conditions should always be performed.

Key Advantages

Sikaflex®-298 provides several benefits for marine deck applications:

• Long open time – Allows comfortable and controlled application over large areas
• Lightweight thixotropic consistency – Provides excellent sag control and easy handling
• Sound-damping performance – Helps reduce vibration-related noise
• Elastic behavior – Adapts to movements of the boat structure
• Free from highly flammable solvents
• IMO compliant

Technical Properties (Summary)

• Chemical basis: One-component polyurethane
• Color: Brown
• Curing mechanism: Moisture curing
• Density (uncured): ~1.2 kg/L
• Skin formation time: ~100 minutes (23 °C, 50% RH)
• Shore A hardness: ~30
• Tensile strength: ~1.2 MPa
• Elongation at break: ~600%
• Service temperature: –50 °C to +90 °C
• Consumption: ~1.2 L/m² (with 4 mm notched trowel)
• Packaging: 600 ml sausage, 10 L pail
• Shelf life: 12 months for sausages, 9 months for pails (≤25 °C)

Application Procedure

Surface Preparation

Surfaces must be clean, dry, and free from dust, oil, grease, and other contaminants that may reduce adhesion.

For long-term bonding performance, Sika surface preparation guidelines should be followed. Testing on actual substrates before application is recommended.

Application

• Application temperature should be between +10 °C and +35 °C.
• The ideal application range is +15 °C to +25 °C.
• The adhesive should be applied using a notched trowel with approximately 4 mm tooth depth.
• On non-moisture-permeable surfaces or when faster curing is required, approximately 10 g/m² of light water mist can be sprayed onto the adhesive surface before bonding.
• After positioning, the deck elements must be firmly pressed to eliminate air gaps.
• The bonded surfaces should remain under pressure for at least 3 hours.
• Open time becomes shorter in hot and humid environments. If a surface skin has formed, bonding should not continue.

Cleaning

• Uncured adhesive can be removed from tools and equipment using a suitable cleaner or solvent.
• Cured material can only be removed mechanically.
• Solvents should not be used for skin cleaning; suitable hand-cleaning products should be preferred.

Limitations

• Not suitable for PE and PP surfaces.
• Application conditions may vary depending on temperature and humidity; site verification is important.
• Components must be bonded within the open time before skin formation occurs.
• Suitable only for professional users.

Conclusion

Sikaflex®-298 provides a reliable marine bonding solution for teak deck applications with its long open time, elastic structure, and sound-damping performance.

Its lightweight thixotropic formulation allows controlled and comfortable application over large deck areas. By adapting to the thermal and mechanical movements of marine environments, it helps create durable, quiet, and long-lasting deck systems.

Frequently Asked Questions (FAQ)

Where is Sikaflex®-298 used?

It is used for teak deck installations and synthetic resin-based deck coverings on GRP, marine plywood, steel, and coated metal surfaces.

What is the difference between Sikaflex®-298 and Sikaflex®-298 FC?

Sikaflex®-298 provides a longer open time, making it more suitable for hot and humid climate conditions.

What is the consumption rate?

Approximately 1.2 L/m² when applied with a 4 mm notched trowel.

What is the skin formation time?

Approximately 100 minutes at 23 °C and 50% relative humidity.

How can curing be accelerated?

A light water spray can be applied onto the adhesive surface before bonding to support faster curing.

How long should the bonded parts remain pressed?

The parts should remain under pressure for at least 3 hours. Full curing time depends on environmental conditions.