Spraying varnishes: Instructions & tips

Whether it be wood, metal or other surfaces: varnishes are suitable for a range of applications and great for sealing tasks. The easiest way to apply lacquer paints is to spray them on directly. Learn here how best to proceed when spraying varnish, what you should look out for, why it's worth spraying varnishes and what the best equipment is for it.

What are varnishes?

Varnishes are made up of volatile solvents and aqueous materials. Varnish is based on a solvent and binding agent. The solvent evaporates during the drying process and leaves behind the non-volatile components as a solid film. The binding agent ensures that all components combine to form a homogeneous mixture, guarantees bubble-free drying and is also responsible for the shine after drying. Other, non-volatile components include pigments, oils, resins, fillers and additives. The pigments provide the colour while resins are important for the varnish's adhesion to the base and producing a glossy finish. Often, calcium carbonate, barium sulphate or kaolin are used as fillers and help to adjust the degree of shine and surface structure, as well as acting as pigments providing colour. Additives are auxiliary ingredients that are added for specific extra functions. These might be biocides, for example, which prevent the formation of micro-organisms and therefore give the varnish a longer shelf life.

There are three main tasks that a varnish should accomplish:

Protection

Protection

A coating of varnish protects surfaces from the effects of weather, stress and other external influences.

Decoration

Decoration

The varnish beautifies the surface with colour and shine.

Function

Function

With certain varnishes, a surface can be given specific properties. Electrical insulating varnish, for example, changes the surface's electrical conductivity.

Various compositions mean that there is a varnish available for every purpose. Effect varnishes are ideal for decorative elements, while clear varnishes are good for colourless sealing. Piano lacquers, on the other hand, produce a particularly smooth and glossy finish. In the industrial sector, the most well-known varnishes are car varnishes, which protect the panels from corrosion.

What advantages do varnishes offer?

  • Varnishes are low-viscosity materials. This means they are generally easy to work with.
  • Varnishes can be used in an incredible number of ways thanks to their many different compositions.
  • With one varnish you can give surfaces brilliant protection against stress, corrosion and other influences.
  • With others, you can even influence how an object works.
  • Varnishes stick to smooth surfaces such as metal, but also to rough surfaces such as wood.

Painting vs. spraying varnishes

Especially with varnishes that are intended to offer protection, even and seamless application is essential. You would want an even result with decorative varnishes, too. When varnishing with a brush or roller, however, the object's own structure is also spread around - everyone is familiar with the little notches in the varnish caused by brush hairs. To achieve a smooth, glossy layer, spray systems are ideal because they guarantee even application. The atomised droplets of varnish also effortlessly reach every corner, ensuring that even hard-to-reach parts are sealed cleanly.

Spraying varnish saves you time and effort and even, full coverage is guaranteed. With WAGNER paint spray systems, the spray mist is minimal and you can therefore work fatiguefree - and many users find it great fun. Further advantages of spraying can be found here in our FAQs.

Instructions: how to spray varnishes with our paint spray systems

Have you decided to spray varnishes with the WAGNER paint spray systems? With the following 5 steps, ensure that you are applying the varnish perfectly.

Step 1: Personal safety and object preparation

Prepare object

When working with varnishes and glazes especially, it is important to wear protective clothing - so safety goggles and a face mask. On untreated surfaces, wipe any dust or dirt off using a cloth. On objects that have already been treated, take some sandpaper and roughen up the surface well. The varnish can only stick onto a well-prepared surface. Otherwise, you risk the varnish peeling off quickly and the object not being protected properly.

Prepare work surface

Also think about your surroundings (such as the floor or furniture) and cover them with a dust sheet or conventional cling film.

Step 2: Dilute the varnish

Dilute the varnish

Varnishes can be diluted by up to 10% before they are sprayed in order to achieve as even coverage as possible. Simply use the stirring rod included in the scope of delivery. It has notches on one side, with each notch representing 10%. So pour the varnish into the spray unit's varnish container and place the stirring rod in it. You can now see which notch the varnish reaches up to. Simply add water up to the next notch and stir well.

Tip: Paints and varnishes are easier to work with at room temperature. If necessary, you can easily dilute your varnish with warm water.

Step 3: Preparing and setting the device

Preparing device

You need to set your device differently, depending on the spray system. On HVLP devices, the parameters to be adjusted are the air flow and the volume of material, while on airless devices it is the pressure level.

If you are spraying varnish for the first time, we recommend starting with a low volume of material and increasing the amount as you become more practised. Test your settings beforehand using the test poster supplied or using a piece of cardboard.

Step 4: Spray the varnish

Spray the varnish

It is important to maintain an even distance from the surface at all times. With HVLP spray systems, this distance is 5 - 10 cm, while with airless devices it is 25 - 30 cm. Hold the device at an angle of 90 degrees to the object and ensure that you do not make any swivel movements in the process. Do not activate the trigger guard until after you have started your movement and release it before the end of the movement. This will avoid excess varnish application at the spray points at the beginning and end.

Spray the varnish

On larger surfaces, we recommend using a cross-wise pattern. Cross-wise is a painting and varnishing technique in which you first spray on a horizontal layer, then a vertical layer.

Step 5: Cleaning the unit

Cleaning the unit

The HVLP paint spray systems can be conveniently dismantled and the varnishes removed and cleaned using a warm and suitable cleaning product, such as water or a solvent. This is very simple with airless devices. Simply plug the varnish intake hose and the return pipe hose into the container with cleaning fluid and allow the pump to run. The device then cleans itself. Here too, you can easily remove and clean the suction system, nozzle and gun filter. Further information on cleaning WAGNER paint spray systems can be found here for airless sprayer and here for HVLP sprayer.

Tip: Ideally, clean your device immediately after using it because varnish is easiest to remove when it is still fluid.

Which paint spray system for varnishes?

At WAGNER, we have two different types of device for spraying varnish: the "High Volume Low Pressure" (HVLP) spray units and the airless spray units. Both are ideal for spraying varnishes.

Spraying varnishes with our HVLP paint spray systems

Our HVLP (High Volume Low Pressure) devices are designed for low-pressure spraying. With a high volume of air and low air pressure, the varnishes are atomised by the air as they exit the nozzle. The low material pressure means that the material droplets are slightly larger and the spray mist is significantly reduced as a result. We recommend the following HVLP spray units for spraying varnishes: 

Wood&Metal Sprayer W 100

Wood&Metal Sprayer W 100

The handy solution for small and medium projects

Wood&Metal Sprayer W 150

Wood&Metal Sprayer W 150

The compact spray system for paint and varnish

Universal Sprayer W 575 FLEXiO

Universal Sprayer W 575 FLEXiO

Universal Sprayer W 590 FLEXiO

Universal Sprayer W 590 FLEXiO

The compact hand-held paint sprayer for interior and exterior use

Universal Sprayer W 690 FLEXiO

Universal Sprayer W 690 FLEXiO

The universal paint sprayer for interior and exterior use

Universal Sprayer W 950 FLEXiO

Universal Sprayer W 950 FLEXiO

Effortless paint application on walls and ceilings

Spraying varnishes with our airless devices

With airless devices, the varnish is not atomised by the air, but rather simply by the material pressure. The material is broken up in a spray jet. The airless spray devices are especially useful for craftsmen and enthusiastic DIY-ers undertaking larger renovation projects. This means you can varnish fences, garage doors or car ports perfectly, for example. We recommend the following airless devices if want to apply varnish regularly or in large quantities:

Airless Sprayer Control 150 M

Airless Sprayer Control 150 M

The perfect gateway to WAGNER's world of airless paint spraying

Airless Sprayer Control Pro 250 M

Airless Sprayer Control Pro 250 M

Perfect control when spraying with Airless technology

Airless Sprayer Control Pro 350 M

Airless Sprayer Control Pro 350 M

Professional airless paint spraying with up to 55% less overspray and maximum control

Airless Sprayer Control Pro 250 R

Airless Sprayer Control Pro 250 R

Airless paint sprayer from the latest generation — user-friendly and precise

Airless Sprayer Control Pro 350 R

Airless Sprayer Control Pro 350 R

With the latest Airless spray technology for uniform and effective paint application