NISO PU marine clearcoat is a high-performance topcoat designed to withstand the harsh conditions of marine and outdoor environments. It is a latest-generation, two-component polyurethane varnish formulated without isocyanates, which offers a significant technical and regulatory advantage whilst maintaining first-class mechanical and chemical properties.
Detailed offers
Product supplied as a complete kit
kit 1L: 500 ml marine clearcoat + 500 ml hardener
kit 2L: 1 litre marine clearcoat + 1 litre hardener
kit 10L: 5 litres marine clearcoat + 5 litres hardener
A high-performance coating for extreme conditions
This clearcoat stands out for its ability to withstand external stresses over the long term. It offers exceptional protection against ultraviolet radiation, thereby minimising yellowing and premature deterioration of surfaces exposed to sunlight. Its gloss retention is remarkable over time, making it an ideal solution for visible and decorative surfaces.
In addition, NISO offers excellent resistance to wear and abrasion, helping to preserve the integrity of surfaces subjected to repeated mechanical stress. Its excellent tension ensures a uniform and attractive finish, free from surface defects, even on complex substrates.
Classified in accordance with AFNOR T 30 003 – family 1 – class 6, this varnish meets the requirements for high-performance coating systems intended for technical environments.
Areas of application: boating and technical support
NISO marine varnish is specifically recommended for applications above the waterline. It is ideal for protecting and finishing the upper parts of boats, such as decks, masts and wooden structures.
Its high versatility also means it adheres effectively to a wide range of surfaces, provided they are properly prepared:
Wood (solid wood, MDF, chipboard, OSB, plywood)
Metal substrates (steel, aluminium)
Composite substrates (polyester, gelcoat)
Various technical surfaces
This multi-platform compatibility makes it an ideal solution for professionals looking for a single product capable of handling a range of applications.
Essential technical specifications
The clearcoat is a two-component liquid paint containing an isocyanate-free polyurethane resin. It is available in a gloss finish, whilst remaining colourless to preserve the natural appearance of the surfaces.
The mixture is prepared by combining equal parts of the hardener (1:1 by weight), with a pot life of between 12 and 24 hours at 20°C, offering good ease of use.
Technical performance is based on several key parameters:
Solids content: approx. 60%
Recommended film thickness: 60 to 80 dry microns per coat
Theoretical coverage: approx. 8.8 m²/L
Fast drying: dust-dry in 30 minutes, touch-dry in 2 to 3 hours
Fully cured: 7 days
The VOC content is around 480 g/L depending on the colour, which is in line with the standards for technical polyurethane systems.
Preparing the supports: a crucial step
The performance of the clearcoat depends directly on how well the surfaces have been prepared. Each surface requires specific treatment:
Pre-varnished wood in good condition: cleaning, light sanding (180–320 grit), followed by the application of several coats.
Deteriorated wood: complete stripping, sanding, followed by the rebuilding of the varnish system.
Raw wood: progressive sanding, a heavily thinned first coat for impregnation, followed by finishing coats.
Steel: degreasing, sandblasting or mechanical preparation with controlled surface roughness.
Aluminium: appropriate sanding or sandblasting to ensure adhesion.
Gelcoat / polyester: degreasing to remove waxes, followed by matting.
It is recommended that you sand the surface between every two coats to ensure optimal adhesion and a high-quality finish.
Strict conditions of application
To ensure the product performs as intended, certain conditions must be met:
Ambient temperature between 12°C and 30°C
Substrate temperature 3°C above the dew point
Relative humidity below 70%
Substrate must be completely clean, dry and free from contaminants
Good ventilation is essential, particularly in enclosed spaces, to ensure safe application and proper curing of the film.
Application methods
NISO clearcoat can be applied using a variety of equipment:
Brush or roller: apply undiluted
Air spray gun: dilute by 10–25% to adjust the viscosity
Electrostatic spray gun: a specific version is available
Airless: not recommended
This flexibility makes it possible to adapt the product to a range of applications, from small-scale DIY projects to industrial production.
Packaging and storage
It has a shelf life of 12 months in its unopened original packaging, provided it is stored in a well-ventilated area at a temperature between +5°C and +35°C.
Safety and precautions
As with any technical product, safety instructions must be followed when using this varnish. It is essential to read the label and the safety data sheet before use.
Finally, it is important to note that the final performance depends heavily on the application conditions and the nature of the substrates. The user remains responsible for ensuring that the product is suitable for their specific application.
FDS CLEARCOAT MARINE 
