Paint consumption
Consumption of paint or other material (for example, mortar for plaster) when the spray gun is operating in normal mode.
The higher the flow rate, the more material the tool can apply per unit of time, the better it is suitable for processing large areas and for applying thick coatings. On the other hand, not all types of work require high productivity, and sometimes relatively low consumption is optimal. Detailed recommendations on this subject for different situations can be found in special sources.
Maximum viscosity
The maximum viscosity of the paint or other working material at which the spray gun is able to work normally. Specified in DIN units; a certain DIN in this case is the number of seconds it takes for a standard volume of paint (usually 100 mL) to pour out of a funnel with a strictly defined pour hole diameter (usually about 4 mm). Such a funnel (viscometer) can be supplied with the spray gun, but if necessary, it can be purchased separately.
Thus, the larger the DIN, the more viscous the composition is. And the larger the number indicated in the characteristics of the spray gun, the wider its capabilities, the thicker liquids can be poured into it without fear of clogging and breakage. At the same time, it should be taken into account that in fact it is not so often necessary to work with thick liquids — on the contrary, excessive viscosity worsens the quality of the coating, leads to streaks and increases the drying time. For example, most enamels and oil paints are used at a viscosity of about 20 DIN, latex paints up to 45 DIN, etc. General recommendations on this matter can be found in special sources, and specific ones can be found on the packaging of a particular brand of paint or other composition.
Nozzle size
The diameter of the nozzle at the outlet of the spray gun.
It is from this nozzle that paint or other working material comes out. And the productivity and spot size at the exit depend on the diameter. Accordingly, larger nozzles are better suited for processing large surfaces, while smaller nozzles provide greater precision and accuracy. Thus, this parameter is directly related to the type of device (see above). There are also
spray guns with a replaceable nozzle, when more than one nozzle is provided in the kit, which expands the possibilities of using the device.
Spray system
The type of spray system used in the device. Different spray systems differ in the format of work and, as a result, in individual practical nuances of use:
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HP (High Pressure) / CONV (conventional). One of the most famous and popular spray systems. The air pressure at the inlet and outlet of such spray guns is approximately the same. The advantages of HP systems are the simplicity of design, large working width, high paint application speed and relatively low air consumption. At the same time, the percentage of paint transfer in such sprayers is very low — more than half of the applied material bounces off the surface due to high speed and settles on surrounding objects. Another disadvantage is that the flow from the HP atomizer picks up fine dust and other "flying debris" heavily; because of this, additional grinding and polishing of the painted surface is often required.
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RP (Reduced Pressure). Modification of conventional (HP) atomizers, characterized by a slightly reduced outlet pressure. This allowed for some improvement in the transfer coefficient and reduced debris levels while maintaining the advantages of good performance, uniformity and low air consumption. Nevertheless, according to these indicators, such devices are still inferior to low-pressure models.
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HVLP (High Volume Low Pressure). Spray system with reduced outlet pressure (a
...pprox. 0.7 bar) and large air volumes. One of the key advantages of such devices is a high ink transfer coefficient of at least 65%. In addition, the low speed of the paint supply reduces the level of debris: there are relatively few turbulences that “pull” debris along with them. The main disadvantage of HVLP systems can be called high air consumption; not every compressor can handle such an atomizer. In addition, they require additional filters to protect against oil and moisture entering the air during high compressor loads; and you can work with such a device only at a short distance (usually up to 15 cm), and in order to avoid drips, a certain skill is required.
— HVLP-II (New High Volume Low Pressure). The second generation of HVLP (see the relevant paragraph), which has a number of improvements compared to the original, but is generally similar.
— LVLP (Low Volume Low Pressure) / Trans-Tech. Spray systems developed as an improvement to HVLP. With the same advantages (high transfer coefficient, minimum debris), they consume much less air and have softer requirements for compressors and hoses. In addition, LVLP systems are less sensitive to pressure drops, and the effective spraying range in them reaches 25 – 30 cm. Of the notable disadvantages of this option, one can only mention a rather high cost.
— HVMP (High Volume Middle Pressure). Spray systems with high air flow and medium outlet pressure. Compared to HVLP, due to the higher pressure, they give a slightly lower ink transfer efficiency, but greater uniformity and range.
— LVMP (Low Volume Middle Pressure). Spray systems with low air consumption and medium pressure; a kind of modification of LVLP, characterized by higher pressure. Due to this, the cost is somewhat reduced, productivity, uniformity of application and capture width are increased; however, paint consumption is higher and the finished surface is rougher than original LVLP.
— HTE (High Transfer Efficiency). This marking is used in spray systems for which a high transfer coefficient is claimed by the manufacturers. In terms of characteristics, they are most often similar to LVLPs (see the relevant paragraph) — in particular, they have a rather large effective range. However, specific features in each case should be clarified separately.
— EA (Excellent Atomization). The main feature of such systems, in accordance with the name, is a very high degree of atomization of the material. Other performance characteristics in such systems may be different, these points should be clarified separately.
— HEA (High Efficiency Airless). Proprietary airless spray technology (see "Spray") used in the Wagner brand technique. Reduces paint wastage by more than 50% compared to more traditional systems, as well as more even material distribution, according to the creators. Suitable for water and oil based coatings.
MP (Middle Pressure). Transitional option between the HP and RP described above: it provides a slightly lower working pressure compared to HP, but not as low as in RP. For a number of reasons, it did not receive distribution.
HD (Heavy Duty). A marketing designation used on individual sprayers, typically high-capacity, high-volume sprayers. The specific characteristics of such systems should be clarified separately.Container volume
The total volume of the paint reservoir supplied with the gun.
Large tank, on the one hand, allows you to "charge" a lot of material and work for a long time. On the other hand, it increases the size and weight of the device; and a large amount of paint will also weigh accordingly (although for models with a separate tank location - see above - this is not critical). Therefore, the thinner and more delicate the work for which the spray gun is designed, the, as a rule,
the smaller the tank volume : for example, in airbrushes (see "View") it rarely exceeds 50 ml, and in plaster models, in turn, can be measured liters. Therefore, most models have a volume of no more than a liter, namely
500 ml,
600 ml,
700 ml,
800 ml,
1000 ml.