Spraying with glazes: It’s so easy with our tips

As beautiful as wood is, it can be susceptible to mould and algae, pests such as woodworm and simple weathering. The application of a glaze helps to protect the wood and maintain its durability in the long term. Read on to find out more about glazes and how to apply them.

What are glazes?

Glazes are a mixture of solvents (or a water base), binders, possibly colour pigments and fillers as well as additives. Solvents can dissolve substances without chemically binding them and are therefore used to liquefy the glaze. After applying the glaze, the solvents or the water base evaporate, leaving behind only the solid components. The binders – usually alkalis or, in the case of a water base, water-diluted acrylics – bind the glaze to form a homogeneous, processable liquid. The colour pigments and fillers provide the colour tint, and typical additives may include fungicides and biocides. When applied, these kill algae, bacteria, insects and fungi – and continue to protect the wood against pests.

  • A general distinction is made between the thick and thin-layer glazes. The latter penetrate into the wood and, as the name suggests, remain there as a thin layer. This means the wood grain is still visible after application, even with coloured glazes. Water cannot penetrate into the wood fibres; however, water vapour can pass through the glaze. This is particularly important if sapwood is used alongside heartwood. As this protective coating on the wood is only very thin, glazes must be applied at regular intervals to ensure long-term protection of the underlying material.
  • The situation is different with thick-film glazes, which are more similar to paints. These leave behind a solid film (usually dyed), which also conceals the wood grain. This layer serves as a complete sealant and also protects the wood against scratches and UV radiation. This type of glaze is often used for decorative purposes (due to the colouring) or for doors and windows.

What advantages do wood glazes offer?

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New lustre

Older woods can be discreetly refurbished using glazes – and thus revived with new lustre.

Older woods can be discreetly refurbished using glazes – and thus revived with new lustre.

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Prevent pest infestation

The durability of the wood is thus ensured in the long term and pest infestation prevented.

The durability of the wood is thus ensured in the long term and pest infestation prevented.

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Fresh wood

Fresh wood often has a very light colour, which can be darkened quite naturally with glazes.

Fresh wood often has a very light colour, which can be darkened quite naturally with glazes.

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Easy application

Glazes are fluid materials and therefore very easy to apply.

Glazes are fluid materials and therefore very easy to apply.

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Colourless protection

Glazes can be used in many ways: while thin-layer glazes can be used both for colourless protection and to add a colour hue to the wood grain, thick-layer glazes provide the option to create a smooth colour layer.

Glazes can be used in many ways: while thin-layer glazes can be used both for colourless protection and to add a colour hue to the wood grain, thick-layer glazes provide the option to create a smooth colour layer.

Spray or brush on the glaze?

Glazes can be applied quite well with special glaze brushes. Due to their longer bristles, these brushes are better able to reach between the wood fibres on the surface than conventional brushes.

Nevertheless, applying a glaze with a spray unit is not only easier, it also saves time, material and effort. Spraying the wood glaze lets you cover a larger surface faster. You will also avoid dripping brushes and a build-up of glaze in cracks and corner. If you want to apply a glaze to your new wooden fence, for example, it can be tricky to properly coat the areas where the slats have been screwed together. While a brush has to be repeatedly stroked over the area, causing a build-up of material there, a spray system can cover every nook and cranny in a single pass. This guarantees complete protection and a sealed finish. Further advantages of spraying can be found here in our FAQs.

Instructions: How to spray wood glazes

WAGNER spray units make spraying wood glazes a quick and simple process. We’ll guide you through the application step by step so that you can safely protect your wooden furniture with a glaze and achieve ideal results.

Step 1: Personal safety and wood preparation

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Because glazes are so fluid and easily atomised, it’s important to wear protective clothing, including safety goggles and a breathing mask. Lightly sand the surface so that the wood can better absorb the glaze and then remove any dust and dirt.

If the wood was previously sealed with varnish, the remnants should be removed – if it was a thin-layer glaze (recognisable by the fact that the grain shows through), it is sufficient to lightly sand the surface.

Before applying glaze to furniture indoors, remember to cover the surroundings (such as the floor) with painter's fleece or standard foil. You can find more information about covering a room here in our FAQs.

Step 2: Prepare the glaze and fill the device

Prepare the glaze

Depending on the manufacturer's instructions and the viscosity of the glaze, you may need to dilute it before spraying. The most convenient way to do this is to pour the glaze into your spray unit’s paint container. If you look at the included stirring rod, you will see some notches on it – each one indicates a 10% dilution. Simply place the stirring rod in the glaze and add a little water until the mixture reaches the next notch.

Stir the diluted glaze well and screw the paint container to the spray gun.

Step 3: Adjust the device

Adjust the device

Depending on which spray system you are using, you will need to adjust your device to suit the application. With HVLP units, this means setting both the material quantity and the air flow; with airless units you only need to set the pressure level. Since glazes are fluid materials, you can set a relatively low pressure and/or air flow on both types of device.

Spray downwards. For example, if you are glazing a wooden terrace, you should align the suction pipe of the HVLP unit accordingly. If you are using a WAGNER spray system for the first time, we recommend starting with a low volume of material and increasing the amount as you become more familiar with the process. You can test your settings beforehand using the supplied test poster or a piece of cardboard.

Step 4: Spray on the glaze

Spray on the glaze

During the spraying process itself, always ensure a constant distance and a constant angle of 90° to the surface. Start moving and then press the trigger to avoid applying too much glaze at the starting point when spraying.

When spraying wood glaze outdoors, make sure that there is as little wind as possible and that you do not accidentally coat your house wall, for example. To protect your neighbour’s plants, you could also place a large piece of cardboard behind the section of fence you are spraying.

Step 5: Clean the spray unit

Clean the spray unit

The HVLP spray systems are very easy to disassemble – simply place the components in warm water and then rinse them out. With the airless units, you can remove the suction systems, the gun filter insert and the nozzle for easy cleaning. The pump cleans itself via the self-cleaning function – just remember to place the suction and return pipe hose in a bucket of water. Further information on cleaning WAGNER paint spray systems can be found here for airless sprayer and here for HVLP sprayer.

Tip: It’s easier to clean the device while the glaze is still liquid.

Which paint spray system for wood glazes?

At WAGNER you will find two different types of device that can be used to spray glazes – the HVLP and airless units. Both are ideal for spraying glazes.

Spraying wood glazes with our HVLP units

If you want to use compressed air to spray wood glazes, one of our "High Volume Low Pressure" (HVLP) units is ideal. The glaze is atomised by means of a large air volume and low air pressure through the nozzle. As the glaze is under low material pressure, the droplets are slightly larger – which in turn reduces the amount of spray mist.

The following HVLP sprayers from WAGNER are ideal for glazing wood:

Fence & Decking Sprayer

Fence & Decking Sprayer

Wood&Metal Sprayer W 100

Wood&Metal Sprayer W 100

Wood&Metal Sprayer W 150

Wood&Metal Sprayer W 150

Universal Sprayer W 575 FLEXiO

Universal Sprayer W 575 FLEXiO

Universal Sprayer W 590 FLEXiO

Universal Sprayer W 590 FLEXiO

Universal Sprayer W 690 FLEXiO

Universal Sprayer W 690 FLEXiO

Universal Sprayer W 950 FLEXiO

Universal Sprayer W 950 FLEXiO

Spraying wood glazes with WAGNER airless devices

In this case, “airless” means the glaze is dissipated into a spray jet via the material pressure alone. These appliances are particularly suitable both for ambitious DIY enthusiasts carrying out major renovations (such as your own terrace) and for trade professionals.

If you need to spray glazes regularly or on a larger scale, we recommend the following airless units:

Airless Sprayer Control 150 M

Airless Sprayer Control 150 M

Airless Sprayer Control Pro 250 M

Airless Sprayer Control Pro 250 M

Airless Sprayer Control Pro 350 M

Airless Sprayer Control Pro 350 M

Airless Sprayer Control Pro 250 R

Airless Sprayer Control Pro 250 R

Airless Sprayer Control Pro 350 R

Airless Sprayer Control Pro 350 R