Ah yes… that perfect finish! We get it, but we also know that achieving this result for your coatings is not always easy. Don’t worry though, we are here to help!
Before we begin, you should know the main characteristics of the Airless spraying system,
What are the main features of an airless system?
It allows you to apply coatings with different viscosities; from lacquers and paints, to putties and plasters.
The benefits of using an Airless Spray System are:
- The fluid atomization in drops is done by applying pressure of up to 160 bar. No air mixture is used and therefore less fog is produced.
- Airless spray systems are highly efficient as a smaller amount of fluids is wasted and because since those fluids are quickly applied, the whole operation requires less labor.
- It allows applying coatings even on rough and ridged surfaces.
- With great versatility, airless technology can be applied indoors, out-doors, facades, industrial buildings, floors and houses.
By contrast, an Airless System can present the following drawbacks:
- Fog is not 100% reduced. A little fog will always be there, but it will be far less than when using low-pressure paint systems.
- Airless equipment requires maintenance. Good maintenance and cleaning your equipment after each use will save you loads of money on repairs.
- Airless coating systems are used on large surfaces. They will not be useful on small areas. These systems are best used for large projects.
Now you have read and understood the main characteristics of the airless equipment, let’s get to it! The next step is to find the right airless nozzle size. First, please check your product’s Technical Data in order to choose your sprayer. After this, it’s time to find the right airless nozzle size!
Getting the right Nozzle size and pressure!
Today, we will show you how choosing the right nozzle or tip size is imperative if you want to obtain the best spraying results. But first, keep in mind that the kind of project at hand needs to be considered.
SAMOA airless tips have a durable tungsten construction with a stainless steel gasket, that allows for a reliable application when spraying a wide range of coatings, including low or high pressure applications. Note that a high-pressure nozzle is identified by the numbers stamped on it:
- The first number indicates the hole size average diameter in thousandths of an inch (mils).
- The second indicates the spray angle
Nozzle size: the spray angle and the amount of paint
Remember that if you want to achieve the best coating results, you MUST choose the right nozzle size first, it is necessary to consider the kind of project that needs doing. The correct nozzle size and spray pressure, are usually indicated on the product’s technical sheet. As a general rule, you can follow the following tips:
- Airless nozzle size 11-20. This nozzle has an average pitch diameter of 11-mil and 20° spray angle. It is suitable for spraying low-viscosity products, such as lacquers and varnishes on small surfaces or with little space to work.
- Airless nozzle size 11-40 This nozzle has the same average pitch diameter of 11-mil, but the spray angle is greater: 40º. When used as above, because the spray angle is greater, the amount deposited per unit area decreases compared to the 11-20 nozzle.
- Airless nozzle size 21-40. This nozzle has an average pitch diameter of 21-mil and 40ºspray angle. As the passage diameter is larger, the amount of coating supplied will be greater under the same circumstances. This size can be used to dispense medium viscosity paints.
- Airless nozzle size 35-40. This nozzle has an average pitch diameter of 35-mil and a spray angle of 40º. As the diameter of the passage is much larger, it can be used in the atomization of highly viscous products such as putties or intumescent paints.
Helpful tip from our Spraying Experts:
- Always use a small nozzle size when applying thin fluids (low viscosity) and a large nozzle size for high viscosity.
- Don’t forget to use the appropriate gun filter for the fluid and the chosen nozzle size. The filter must have a sieve with lesser pitch between its meshes than the nozzle passage. The sieve meshes size should not be larger than the nozzle size, as this could lead to clogging problems.
- In general, the finer the nozzle and the higher the pressure, the smaller the fluid droplets.
Paint sprayers and the MAXIMUM FLOW CAPACITY
Did you know that each painting sprayer has a maximum flow capacity? Be sure to never use a bigger nozzle size than the supported by your equipment!
Every single airless sprayer or product used has its own correct nozzle size range. Please be aware of this and always check it on your product’s technical data sheet!
When choosing the necessary equipment for Airless spraying, remember to account for the following indications:
- Consider, depending on the fluid to be used, the appropriate nozzle size. Once the nozzle and the working pressure have been chosen, you will have an estimate of the necessary flow.
- Determine if you need to work simultaneously with one or more Airless guns. If using more than two guns, you should choose spraying equipment with a displacement 3 times greater.
- If ever in doubt, select the highest pressure and displacement ratio; it’s always more beneficial.
Nozzle Size and the percentage of solids in paints and coatings
As you already know, paints and coatings contain solids in different percentages. De-pending on these values, the recommended nozzle size varies. This is important, because the type of material you are going to spray, determines what type of machine can efficiently handle your spraying project and the nozzle size you need to use.
- Low Solids: 20-30% solids like lacquers, stain, enamels, fixatives, inks…
- Recommended nozzle size from 11-20 to13-60
- Medium solids: 30-50% solids like acrylic paints, emulsions, exterior latex…
- Recommended nozzle size from 15-20 to 21-60
- High Solids: up to 100% solids like fillers, elastomers, plaster, mastics…
- Recommended nozzle size from 23-20 to 51-80
If you want to have a consistent, well-functioning sprayer, you MUST equip it with the right accessories. We generally recommend that you acquire different size nozzles, so you can swap them around and choose the right ones them for the variety of fluids al-lowed by your equipment.
Selecting the right nozzle size will benefit your spraying equipment:
- Saving time and fluids
- Less replacement
- Reduced workload, fewer coats, less overspray
- Improved finishing quality and increased productivity
PLEASE know your application process very well: then choose your equipment!
It is mandatory that you as a coatings applicator shall carefully consider all different jobs you will be performing with your spraying equipment. You will need an airless sprayer suitable for your different needs. Did you know that there are many different pumps depending on the fluid to spray? Pneumatic, electric-piston, electric diaphragm… Please, research your intended application before you purchase your equipment!
For example, you have purchased some new spraying equipment for paint, but you know you will be also spraying stucco in the near future. If I were you, in this case I would not then be purchasing an electric diaphragm pump, as it’s unsuitable for this application.
Get some helpful tips from our Spraying Experts:
- Nozzle size and pressure determine the material flow rate
- Check the product’s technical data sheet.
- Each sprayer has its tips range based on its power and the products it can spray
- The fluid used must be suitable for an airless application.
- Use the appropriate filter size
- Use original accessories only to guarantee the best performance for your equipment
- Don’t forget to clean your sprayer with a fluid compatible to the material you are going to spray. This way you avoid any fluid residues drying out inside the pump, its components and accessories.
- The airless nozzle durability depends on the fluids it will spray. However, increasing it is possible if the sprayer works at its lowest pressure with a good atomization
Talking about a GOOD ATOMIZATION, which by the way cuts down the paint expenses, want to know the rules?
- Reduce the spray pressure. Do so only so the jet obtained is adequate. Depending on the product to be applied and the size of the nozzle used, there will always be an optimal application pressure. Pay special attention to the pressure, as it needs to be as low as possible.
- Adapt the jet width to the dimensions of the area to be painted.
- Always be sure to maintain the same distance of 30 cm between the spray nozzle and the surface.
- Keep the gun straight and perpendicular to the surface, making a 90 ° and moving it parallel to it.
- Maintain the correct product application ‘rhythm’
- Only squeeze the trigger if you keep the gun moving. Otherwise you will have areas with a high load of product that can lead to streams of material and generally a defective finish.
Just some final thoughts to help you look after your equipment
Based on the applicators experience, a nozzle generally tends to exhaust its spraying effectiveness after 300 to 500 litres of paint. Nonetheless, such values can drastically decrease if the paint sprayed is very abrasive, or the sprayer is used at a high pressure and the surface to be covered is really extended.
Still have doubts or are considering renewing your spraying equipment?
CONTACT US and we will provide all the information you need or download our Protective Coatings catalogue!
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