Waterborne coatings for exteriors

Durability has always been the first evaluation criterion of exterior- grade wood coatings. With the SAYERLACK HYDROPLUS waterborne coatings, the life of coated wood joinery has considerably increased. These products are designed for the reduction of water absorption and protection from the sun's radiation, as well as for the protection against fungi, and they ensure several advantages in terms of outdoor resistance and solvent emission reduction.
Longer life on outdoor exposure, twice compared to air- drying products. Waterborne wood coatings keep a high elasticity rate in time, unlike solvent-based products, which due to radicalic reactions within the film originated by UV rays, become so brittle over time that they tend to crack.
Solvent emission abatement: by 90%. Better quality of life for those who apply these products and drastic pollution reduction. Waterborne coatings are not flammable, can be thinned with tap water, allow fast coating systems without spontaneous combustion and lifting.

Advantages arising respectively from the use of waterborne and alkyd- based products in the manufacture of joinery for exteriors.

WATER-BASED WOOD COATINGS
Solvent emission abatement
Not flammable
Equipment can be washed with water
Short drying time
Durability on outdoor exposure
Gloss retention
Non-yellowing film
Resistance to skin formation
Maintains its elasticity on ageing
Lifting resistance (over-coatability)
No spontaneous combustion
Even colour

ALKYD-BASED WOOD COATINGS
Better application conditions
Resistance to cold, fungi and bacteria
Initial gloss
Blocking resistance
Chemical resistance
Limited grain raising
Can be applied on all wood species
Price

The SAYERLACK HYDROPLUS clear and pigmented thixotropic Topcoats exhibit good elasticity, no ''blocking'', good vertical hold, excellent flow and good resistance to settling. In order to ensure a good resistance on outdoor exposure, the clear products of the HYDROPLUS series are formulated with an optimal dose of UV absorbers, with the addition of free radical scavengers. While UV absorbers reduce the yellowing and lignin destruction, the UV scavengers increase the outdoor life of the film, since they reduce chalking and gloss loss and increase the UV absorber efficiency. In the case of pigmented products, the choice of high opacity pigments (with a UV filter action), combined with the addition of radical scavengers, has resulted in the highest quality coatings.

The most important precautions to be observed in the use of waterborne coatings are:
1) During application, for both the product and for the substrate and for the environment, a minimum temperature of 15°C should be maintained. Films formed below such temperature exhibit lower mechanical and chemical resistance properties than the standard quality values.
2) Products must be stored in places with a minimum temperature of 5°C.