NISO PU Marine Varnish – long-lasting protection for boats and decks

NISO PU Marine Varnish is a finishing solution specially designed to protect and enhance boat surfaces exposed to marine conditions. 

This new-generation, isocyanate-free, two-component polyurethane varnish meets the high standards of the marine industry by offering long-lasting protection against external aggressions.

Available as complete kits:

1-litre kit: 500 ml marine varnish + 500 ml hardener

2-litre kit: 1 L marine varnish + 1 L hardener

10-litre kit: 5 L marine varnish + 5 L hardener

The benefits of a professional-grade varnish

Designed for applications above the waterline, this varnish is ideally suited to the visible and high-wear parts of boats: decks, superstructures, masts, wooden panels and technical components. It preserves the aesthetic appearance of the surfaces whilst ensuring excellent long-term durability.

One of NISO’s key strengths lies in its very high resistance to UV radiation. In a marine environment, constant exposure to the sun accelerates the ageing of materials. This varnish effectively limits yellowing and loss of gloss, guaranteeing a durable and stable finish. Its excellent gloss retention makes it an ideal choice for boats requiring a polished aesthetic finish.

In addition, it offers remarkable resistance to abrasion and wear, which is essential for high-traffic areas such as decks or frequently handled surfaces. Its ability to form a uniform film with excellent tension results in a smooth, even and flawless surface, thereby enhancing the boat’s appearance.

Compatibility and substrates

This marine varnish is compatible with a wide range of substrates used in boatbuilding, provided they are properly prepared: solid wood, plywood, MDF, aluminium, steel, polyester, gelcoat or composite materials. This versatility means it can be used for both renovation and finishing on new boats.

Mixing the two components

The two-component system requires precise mixing with the hardener, in a 1:1 ratio by weight. Once prepared, the product offers a comfortable pot life of 12 to 24 hours at 20°C, which facilitates work on large surfaces. Drying is rapid: dust-free in around 30 minutes, touch-dry in a few hours, with full cure in one week. 

Dilution can be carried out using our V1 thinner if necessary, up to 20%, depending on the spray gun nozzle.

Application method

The product can be applied by brush, roller or spray gun, depending on requirements and site conditions. For spray application, diluting the product by 10–25% ensures the correct viscosity and an optimal finish. It is recommended to apply several coats (usually 2 to 6) to achieve the desired thickness and protection.

Surface preparation is an essential step to ensure the varnish performs effectively. Surfaces must be clean, dry, free of grease and lightly sanded to ensure good adhesion. Sanding between coats further improves the quality of the finish.

Finally, application must take place under controlled conditions: temperature between 12°C and 30°C, humidity below 70% and a non-condensing surface. Good ventilation is also recommended, particularly when working indoors.

Quality guarantee

Available in several formats, NISO marine varnish is a reliable and professional solution for protecting, renovating and enhancing boats, whilst ensuring maximum durability against marine conditions.