Water-based coatings are ideal for coating wood for exteriors

Thanks to the Hydroplus line of water-based coatings produced by Sayerlack, the coated wooden doors and windows will enjoy a better durability. The use of Hydroplus coatings not only provides a better resistance of the wood in the outside but also reduces the emission of solvents.

In general, the durability of surfaces treated with Hydroplus is higher than solvent-based products. Furthermore, by maintaining a high degree of elasticity, these products allow the film of coating to accompany the variations of the wood and avoid its injury.

Summarizing the advantages deriving from the use of water-based products in the production of outdoor doors and windows are:

• Low environmental impact
• Non-flammable
• Cleaning tools with water
• Short drying times
• Longer outdoor life
• Gloss retention
• Non-yellowing film
• No “skin” formation
• Film elasticity
• No removal (over-coating)
• Absence of spontaneous combustion
• High thixotropy of the topcoats

Choose the right coating for treatment and maintenance of wood for exteriors

There is absolutely no better coating and therefore it will be necessary to evaluate case by case which product to use based on the support, the application conditions and the intended use.

Of particular importance are: the impregnation, the application of topcoats, the thickness of the coating and the drying.

IMPREGNATION

The ability to deeply impregnate the wood helps to prolong the durability. For the treatment of external elements Sayerlack advises against the use of clear wood stains for exteriors.

We recommend to apply a first coat of wood stain for exteriors even in case of a lacquered system, this allows to increase the adhesion to the wood of the products used later.

APPLICATION AND EQUIPMENT

In the case of water-based coatings it’s possible to use the most common systems such as airless, airmix and electrostatic spraying. Clearly it will be necessary to make sure that the treated surfaces are suitable for contact with water. In this case it will also be possible to recover the sprayed material.

Checking the equipment before application is always a good habit. Small defects can cause significant problems such as creating air bubbles.

The use of a pre-atomizer and/or a pre-heater has given excellent results in practice. The first improves the spraying of the coating by reducing the incorporation of air and increasing the transparency of the film. The second allows for better film formation of the coating.

It’s recommended to apply the pre-heated coating between 25°C and 35°C.

The equipment must be washed immediately after use with water.

If dry coating films have to be removed, use XA4060, leaving it to act for 6-12 hours, then rinse with water.

We recommend the use of different pumps for the application of water-based or solvent-based products.

General indications for the application of clear water-based products:

Cup                Nozzle 3 mm           Pressure 4 bar

Airmix           Nozzle 11-13           Material pressure 90-140 bar. Air pressure 1-2 bar

Airless           Nozzle 11-13           Material pressure 90-140 bar

THICKNESS OF THE COATING

To obtain the right resistance it’s necessary to apply a wet layer of 250 microns on a window and 300 microns on a shutter. It’s also good practice to check the thickness of the coating with a thickness gauge.

DRYING OF THE COATING

For a correct drying process it’s preferable to choose rooms with temperatures higher than 15°C. As for humidity, a value between 50% and 70% is recommended.

Furthermore, the time required can be influenced by the coating application method.

Coating and treatment of outdoor wood

Coating is a fundamental aspect of the process, however there are other elements to take into consideration when treating wood intended for outdoor use.

At this point it’s essential to accurately assess the type of wood and the treatment to which it’s subjected before coating.

THE CHOICE OF WOOD

Without a doubt the choice of wood is a relevant factor, in this case the selected wood must be healthy, without marrow.

Furthermore it’s necessary to make sure that the wood:

• Do not show fungus.
• No traces of insect attacks.
• There are no transverse splits

Resin bags are not a problem if they are smaller than 5mm.

Regarding the risk of resin leakage, if pine, larch or douglas wood is used, it will not be possible to eliminate the resin by drying.

In fact this type of wood is naturally rich in resin and the heat of the sun will cause it to leak out. Fortunately this event will not affect the protective capabilities but only the aesthetics.

THE TREATMENT OF RAW WOOD

The raw wood is characterized by a surface with an irregular profile, before starting to coating the surface must be treated in order to make it regular.

For an optimal result the sanding must be carried out with progressively finer abrasive papers.

It’s advisable to maintain the humidity level of the wood between 13% and 15% by checking it with a hygrometer.

Coatings for outdoor wood produced by Sayerlack

Sayerlack produces a wide range of products suitable for outdoor wood coating. In particular within the Hydroplus line we find wood stains for exteriors, intermediates, basecoats and topcoats particularly suitable for the purpose.

Natural effect coating systems for outdoor wood

Thanks to the great UV protection capacity of the products AM508/00, AM610/00 and AZ8130/00, it makes them particularly suitable for coating systems on exposed or partially exposed items.

CATAS AND CATAS WKI CERTIFIED SYSTEMS: Sayerlack awards for outdoor wood coatings

The great quality of the coatings and the continuous research carried out by Sayerlack have been awarded with important international awards. In fact, the Sayerlack outdoor coatings have been awarded with the Catas Quality Award, the Catas Quality Award Plus, the Catas WKI Premium and the Catas WKI Premium Plus – Coatings System For Exterior.

HYDROPLUS WOOD STAINS FOR EXTERIORS

AM507

Specific wood stain for exteriors for coniferous wood, meranti and okoumé.

AM507 has a great uniforming capacity especially when used on soft woods. Ideal for impregnation of finger-jointed wood.

AM508

Water-based wood stain for exteriors recommended for completely “natural” systems and in general if very light colors are desired. We suggest, for the completely natural system, the overcoating of the intermediate AM610/00 and of the water-based topcoat for exteriors AZ8130/00

AM546

Specific clear wood stain for exteriors for conifers, meranti and okoumé. It highlights the wood grain, giving it a pleasant appearance. Certified product with CATAS Quality Award, CATAS Quality Award Plus, CATAS WKI Premium and CATAS WKI Premium Plus.

AM549

Clear wood stain for exteriors for hardwoods rich in extractives such as oak and chestnut. Its proven formulation allows to impregnate the wood without problems of sliding and with a reduced lifting of the fiber. The wood stain is available in a wide range of colors.

AM512

Clear colored wood stain for conifers, with high dry residue. Particularly suitable for attic beams, games for parks, street furniture.

AM541

Pigmented insulating wood stain that combines high coverage with excellent flow properties. Reduces spillage of extractives.

AM550/13

White water-based wood stain for first-hand woods for exteriors, whose composition strengthens the structure of the wood, improving its durability. Particularly suitable for fixtures, doors and windows, multilayer panels for doors and outdoor products in general. Applicable to flow-coating and immersion.

HYDROPLUS INTERMEDIATE

AM483 – AM490 – AM610 – AM481

Clear intermediates suitable for flow-coating and immersion coating of wooden items for exteriors. They have good coverage and transparency characteristics. They can be easily sanded but the preventive application of Hydroplus wood stain is still necessary.

The products differ in the percentage of dry residue:

• AM490 is more suitable for coating porous woods.
• AM483 is recommended for manual sanding in a short time.
• AM610 for coating systems in which greater durability is required outside.
• AM481 can be used for coating systems in which greater insulation is required on hard-to-treat woods.

HYDROPLUS BASECOATS

AM473

Clear or lacquered thixotropic basecoat with good sanding, high dry residue and good coverage. Suitable for porous woods such as meranti and okoumè due to the good wettability of the pore.

AM475

Clear or lacquered thixotropic basecoat particularly suitable for automatic sanding. Easy to apply, it stands at the top of the range.

AM402

Pigmented one-pack thixotropic basecoat with excellent insulating properties against extractive substances (tannin, gums, etc.) and some wood resin. Easy to apply and with good wettability, it’s ideal for any type of application.

AM562

Clear or pigmented two-pack thixotropic basecoat to catalyze with 10% AH1545. Excellent for blocking the extractives and the resin even of the most difficult woods to coating. It differs from the other basecoat by its high resistance to chemicals and the high hardness of the film.

HYDROPLUS TOPCOATS

All the Hydroplus Sayerlack topcoats, before being marketed, are subjected to strict tests foreseen by the EN 927-2 standard and to further internal tests that evaluate the durability to the outside.

AZ21**

Clear or lacquered thixotropic topcoat with excellent resistance to water and humidity and a high level of wetting of the product. Good both relaxation and transparency. The presence of UV absorbers allows protection from sunlight. Certified product with CATAS Quality Award, CATAS Quality Award Plus, CATAS WKI Premium and CATAS WKI Premium Plus.

XA99** Series

Thixotropic topcoat for tinting systems available neutral (NN) and white (BB) and 15, 30, 45, 60 gloss versions. The topcoat must be pigmented with the special pastes of the XA2006 series.

AZ69**

Thixotropic topcoat for tinting systems available neutral (NN) and white (BB) with 30 gloss. The topcoat stands out for its high vertical hold and excellent stackability. To be pigmented with the special pastes of the XA2006 series.

AZ63**

Water-based pigmented thixotropic topcoat characterized by excellent coverage, good vertical hold, no sedimentation in the tin and rapid drying. The careful choice of pigments gives the AZ63** topcoat a high coverage.

AZ9030

Clear or lacquered thixotropic topcoat with excellent resistance to water and humidity and a high level of wetting of the item. The particular formulation allows to obtain a very high resistance to UV radiation. All these features make it possible to achieve excellent outdoor resistance.

AZ26**

Water-based pigmented thixotropic topcoats characterized by excellent elasticity, absence of removal phenomena, good vertical hold, good distension, no tin sedimentation and fast drying. In order to guarantee a good duration, it has been formulated with the use of pigments suitable for the outside with good covering power.

AZ32**

One-pack clear thixotropic topcoat. It has excellent distension, transparency and water resistance characteristics. The wet film has an exceptional transparency. This peculiarity allows to apply high product thicknesses without the visual whitening effect during the application phase, typical of water-based products. The high solid residue makes it possible to obtain excellent coverage even in two-coats systems.

AZ34**

One-pack water-based topcoat with qualities of transparency and water resistance that make it innovative in the field of outdoor wood protection.

AZ34** is able to combine high verticality with unparalleled wettability and high blocking resistance to surprising elasticity, setting new milestones for outdoor water products.

AZ97**

Water-based topcoat with elasticity and durability that make it ideal in the field of outdoor wood protection. It possesses the characteristics required in specific industrial uses such as distension, transparency, softness to the touch and resistance to water, in addition to high qualities of elasticity and durability.

AZ8130/00

One-pack water-based topcoat specific for colorless coating systems. For this purpose it’s formulated with a specific mix of colorless UV absorbers that protect coating and wood while maintaining their natural appearance. The coating system includes AM508/00 and AM610/00.