The complete guide to reducing overspray (2023)

Reduce oversprayB. improving your spraying technique by setting the right pressure, choosing the right spray nozzle, or using a handy accessory. This article covers each of these suggestions in detail and includes a video presentation on the topic (Reducing Overspraypart OneEpart II)

What is overspray?

"Overspray" is technically defined as fine paint particles that collect on nearby surfaces due to atomization of the material created during paint spraying.

The term overspray is sometimes loosely defined among amateur and professional painters as "whenever you apply paint to an area you didn't originally intend to apply there". However, not all overspray is the same, and the causes are often very different and require workarounds.

To reduce overspray, let's look at proper spraying technique, choosing the right equipment, and your choice of optional accessories that can make spraying airless paint easier and reduce overspray in the process.

spray technique

Airless sprayer manufacturers have designed the spray tip, tip guard, and gun to operate at the optimum distance and angle from the work surface. You'll be off to a good start if you can remember and practice the following:

Hold gun 10 inches from surface; AND

Align the spray nozzle and bracket perpendicular to the wall.

By pulling the trigger, you move the gun at the same time. Move your hand in the same rhythm as closing a curtain. Use your feet and move your body to maintain spray distance and spray gun angle to the surface. Using extensions and swivels will help you reach larger areas and avoid obstacles.

Typical action resulting in overspray

Point the gun away from the surface.

Spray too far away from the work area (i.e. more than 25cm).

injection pressure

Optimum spray pressure is essential to reduce overspray so as not to release too many paint particles into the air. Obviously, airless paint spraying requires atomizing action to create the spray fan and even coverage of the area, but when spraying at very high pressure, a fine mist of particles quickly develops and falls onto surrounding surfaces.

To find the right spray pressure for your job needs, you need to understand what factors affect spray pressure and what to look for when spraying. If the pressure is too low, your spray pattern will be uneven, with "fingers" forming within the spray pattern and thin segmented bands forming at the top and bottom (when spraying in a horizontal motion). If the pressure is too high, the material will be pushed out of the nozzle orifice with much more force than is needed to do the job.

All else being equal, your working pressure will change based on these factors:

1. Higher viscosity materials (eg plaster, weather resistant emulsion paints) require higher pressures, while thinner materials (eg paints) require lower pressures.
2. machine delivery speed.
3. Spray nozzle selection.
4. material temperature. Heating a material increases its viscosity, which means less pressure is required to achieve the same spray pattern.
5. A longer hose reduces working pressure. When spraying over scaffolding with the airless sprayer on the ground, the material must also fight gravity as the hose rises, which also reduces pressure at the gun (point of material delivery to the surface).
6. Inlet tube diameter. Smaller sizes reduce working pressure.

When the machine does not seem to be working efficiently. Check for clogs, clean filters and replace worn spray tips.

Tiny

Its spray pattern looks segmented with a thin stripe across the top and bottom. Stripes or "fingers" are present in the spray pattern. The paint looks too thin and your immediate instinct is to repaint it. (This differs from jobs that only require two coats of paint.)

Too much

The paint begins to run, with drops running down the spray pattern. A visible fog envelops the work area.

Precisely

At an ideal pressure setting, the spray fan pattern has uniform coverage with no visible fingers or segments on top or bottom.

Finding the right spray pressure: step by step

How to find the ideal spray pressure:

1. Start with a low setting and do a test spray.
2. Check the finger spray pattern and decide if you are satisfied with the coverage.
3. Gradually increase pressure until surface is evenly covered with no fingers or visible segmented areas of color.

If you have experience with the same machine, you'll have a good understanding of which materials require a particular print without having to do rigorous testing every time.

Typical action resulting in overspray

Airless device pressure setting too high. Find the ideal spray pressure using the steps above.

spray tip

There is some disagreement among professional painters about which spray tips produce the most and least overspray. There is no one-size-fits-all approach, as your spray tip will depend on your gun setup, spray method and the material you are using. You may also be limited in your choice of spray nozzle if it's niche work eg road markings or heavy materials.

At a minimum, be sure to match the spray tip to the material you are using and the requirements of the job. Paint and other materials will have a “recommended spray tip size” on their specification sheet. Make sure the gun filters are clean and that you are operating the machine at the proper pressure. To reduce pressure, choose a smaller hole point. To reduce spray, choose a spray tip with a lower starting number.

When examining and researching spray nozzles that produce less overspray, the two most commonly cited options are flat nozzle and low pressure nozzle.

flat tips

Some older professional painters opt for the flat tips used with fine cone filters in the spray gun tip (barrel of a regular spray gun). Flat tip edges are claimed to be smoother and have less interference than reversible tips and therefore produce less overspray. As this nozzle design is out of date, we are not convinced that this nozzle produces less overspray than newer designs and may have more to do with the technical knowledge of experienced painters.

Examples of products:

• titanium flat tips
• Graco flat tips

low pressure spikes

Spray nozzle manufacturers have improved the technology of spray nozzle designs so they can operate at lower working pressures. At lower pressures, less material is finely separated into the air, reducing overspray. Low pressure tips last longer and are easy to use - color and number coded to ensure you know which tip you are using.

Examples of products:

• GracoFF LP-TippsELP-Tipps
• wagnerHEA ProTip
• Titan TR1 HEA-Spitze

Typical action resulting in overspray

(Video) Reducing Overspray - Tips, Tricks and Accessories with Airless Discounter Part 2

Incorrect nozzle size selection for job or material requirements.

For more information on choosing the right spray tip, see ourultimate guide to choosing the right spray tip (article)

Masking, plastic cover and shields

For the sake of completeness it should be mentioned that in most cases overspray can never be completely eliminated. Therefore, it is better to cover important furniture with a plastic cover and cover and cover fixtures and fittings accordingly. If you work outdoors, you can use the same plastic pull caps to cover small trees and shrubs.

A cardboard "shield" attached to an extender is used as a cheap and reliable trick to control overspray, especially when working outdoors. Cardboard can also be used as a surface to start and stop the spray pattern, creating a uniform pattern on the work surface. This is especially true when using an extension without a second valve.

Typical action resulting in overspray

Covering all surfaces with plastic, cardboard, and other protective coverings is an expensive and time-consuming process. It is always best to make sure you have the spray technique correct and are using your equipment correctly, with the optimal spray pressure setting, before resorting to masking all surrounding objects and blocking overspray on all the opportunities. Sure, you can mask and mask as you normally would when working indoors or outdoors, but if you're worried about overspray ending up on cars parked across the street, you probably sprayed it wrong to begin with!

extensions or spears

When you're working in larger areas, especially exterior walls, an extra reach ensures you keep your gun spacing and spray angle at an optimal working position.

An extension that sits between the bit holder and the gun itself is available in a variety of sizes from 25cm to 180cm!

Extension threads come standard at 7/8" to fit most modern pistols. If you have older pistol models, you may need an adapter to convert the 11/16" to a 7/8".

Product example:FARBMAX Extensions

Some professional painters find that using extensions always results in overspray, while others find that using extensions makes the workflow much easier and allows you to maintain an optimal working distance from the spray surface. It's probably best to try it yourself and see what works best for you.

An unfortunate new problem arises with the use of extensions, which is the formation of droplets on either side of the spray pattern. When the trigger is pulled or released, the pressure delay created in the extension causes thicker drops of paint to come out of the gun, known as a "squirt". Manufacturers have developed a second valve at the end of the extension, which also has a rotary function. This means you can adjust the spray angle without getting the residual splatter that often occurs when using simple extensions.

Product example:Graco „Clean Shot“-Ventil

(Shown in image at left, with red nozzle holder and yellow spray nozzle.)

Airless manufacturers have combined these two concepts above to produce an overspray reduction kit. In the product example, Graco includes a Contractor gun and a LineLazer spray tip.

Product example:Graco Overspray Control Kit (OFS)

Kit comes complete with gun and spray tips (321 and 419).

To combat spitting, you have two options:

1. Start spraying right where you want to work and finish right where the painted area is.
2. Use a second valve connected to the front of the extension.

Typical action resulting in overspray

Overspray is reduced, but spatter may occur. It is recommended to use a second valve with its extension, an overspray kit or a roller attachment.

to roll

When priming the drywall, painters opted to spray and re-roll to ensure the material is properly adhering to the surface. This usually means two painters working together, one spraying and one rolling. Reversal was also used as a precautionary measure to create a paint texture that could be brushed off with a smaller roller if touch-ups were needed after the first few coats of paint were applied. By using a roller you ensure that the same texture is maintained in all layers.

To reduce the need for a second sprayer and reduce extension spatter, companies such as Graco and Storch have introduced a combination sprayer and roller accessory kit. A roller is attached to the extension arm and remains stationary while the spray mechanism is adjustable. The standard pistol is replaced with an "in-line" pistol that makes firing the trigger and grip easier while rolling. Spray and roll with the spray nozzle and holder under the roller, spray and roll with the downward motion, and roll with the upward motion only. Some of the paint and spray is trapped on the roller, reducing the release of spray into the environment.

Product example: Stork LeOS

"LeOS" stands for "LEss OverSpray" and is a kit that comes with an extension, a second swivel valve and a roller attachment.

Another way to completely eliminate overspray is to replace the spray nozzle and bracket with a full roller extension, allowing material to enter the roller itself. So there is no atomization and no overspray. The advantage of the combined effect of roller application with the airless sprayer is that you don't have to worry about overspray and the working time is reduced because you don't have to put the roller back in the paint bucket every time - the paint is delivered directly on the roller, through the in-line gun and extension and applied to the surface with a rolling motion.

Product example:

In-line Roller Wagner IR100

Typical action resulting in overspray

none. Control overspray and minimize atomization with a roller attachment, or eliminate it completely with the Direct Paint Compensation Full Roller Head.

Heated hose systems

Another alternative is to simply heat the material you are working with. When the material is heated to a temperature between 20 and 60 degrees, its viscosity increases and thus moves more easily in the pump and hose, requiring less pressure to achieve the same desired spray pattern. Heated hose systems are sold individually and are compatible with most machines or are purchased with the airless sprayer.

Product example:

Wagner SF23 TempSpray (on cart – pictured left)

Wagner SF23 TempSpray (in support - portable version)

This can be an ideal solution when working in colder environments and/or with longer hoses.

Diploma

Overpainting furniture, fixtures, plants and vehicles can be a painter's nightmare. Reduce concerns about overspray by following guidelines, taking precautions, and learning to control your equipment. Tech upgrades and accessories are designed to make your job easier, but first make sure you learn the proper airless spray technique!

If you have any questions about overspray, please contact us at +49 (0) 30 220 15436, complete our contact form below or send us an email. If you want to buy any of the above products, you can check them out atour online store. You can also visit us at ourservice baseduring office hours.

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Questions or concerns?

If you have any further questions or would like to obtain any of the products presented in this article, please contact us at +49 (0) 30 220 15436, fill out ourContact Formor send us an email. If you want to buy any of the above products, you can check them out atour online store. You can also visit us at ourservice baseduring office hours.

references

1. What is overspray. https://www.detailingwiki.org/detailing-miscellaneous/what-is-overspray/
2. Gracchus. CleanShot valve with low overspray.
3. Gracchus. Low Spray Kit PDF.
4. Storch. Airless-LeOS SprayRoller (German version)
5. Wagner. TempSpray Airless Heizschlauchsysteme PDF.