If you decide to paint the car yourself, you cannot do without a spray gun. The first thing you need to understand for yourself when starting work is the rules for setting up a spray gun for painting a car. That is, it is not enough to purchase a tool, you also need to know how it functions; if you want the paint to apply in an even, smooth layer, you need to carefully prepare the device for work. Preparation includes four main stages, any of which should under no circumstances be neglected if the master wants to achieve a high-quality result. To achieve this, when starting painting, you need to fulfill several prerequisites:
- prepare paint for work;
- adjust the required torch size;
- create optimal air pressure for painting;
- Correctly set the paint supply parameters.
If the above points are carried out properly, there will be no problems: the painted surface of the car will become smooth and even. Otherwise, unevenness and drips cannot be avoided. And such a coating will take twice as long to dry. So, first things first.
Getting the paint ready for use
To work, you will need a plastic container or a regular ruler. On the paint packaging, the manufacturer usually indicates the proportions that must be observed when diluting it. To accurately maintain the proportions when mixing paint with the activator, you need a ruler. You can replace it with a plastic container with pre-applied graduations, with which you can measure car paint and hardener.
In order for the spray to be of high quality, it is necessary to add a certain dose of solvent to the already prepared composition. The problem is that the manufacturer does not always indicate the recommended ratio of paint to solvent on the packaging. Experienced craftsmen usually add thinner little by little, monitoring the resulting consistency. Beginners are advised to find a dye with the dilution parameters indicated on the packaging. For example, the inscription on a can 2 x 1+10% means that 1/10 of the amount should be added to the paint diluted with activator in a ratio of 2:1 total number solvent.
To create protection against external influences or “metallic” effect, two layers of coating are applied to the surface of the car: the first is a coloring substance, the second is acrylic varnish. The varnish is diluted in accordance with the manufacturer's instructions. In this case, there is no need to activate the paint: drying is ensured by the solvent added to it.
Adjusting the size of the torch in the spray gun
First of all, you should adjust the optimal width of the spray gun torch. This directly depends on the surface area that needs painting. If a car or part is completely covered with paint, the maximum width is set.
When processing a small area, choose a small torch width, having previously tested the quality of spraying on whatman paper. This will allow you to apply the paint evenly and quickly. It must be remembered that by reducing the width of the torch, you must simultaneously reduce the air pressure.
Adjusting the air pressure
Choosing the optimal pressure supply is not easy. There are many parameters on which this depends: the model of the spray gun, the type of paint, the viscosity index. On whatman paper from a distance of 25-30 cm horizontal position Several test injections are made while simultaneously adjusting the air pressure. Then the resulting prints are carefully examined:
- drops with drips, large – the pressure is insufficient;
- the outline of a figure eight indicates too high pressure;
- a print in the shape of a pear, banana, or crescent indicates a malfunction of the device or a clogged nozzle or air cap;
- ideal shape - an elongated beautiful torch without drips or drops.
Depending on the model of the device, the pressure regulator may be built into the handle or have a removable design. If the regulator is removable, it opens at the junction of the hose with the receiver. If the regulator is built-in, the pressure is changed when the trigger is pulled.
Setting the paint supply
After the torch width and air pressure are set, the paint supply is adjusted. The adjusting screw, screwed in all the way, is released 2 turns. When adjusting, it is not recommended to give a large feed; it is better to do this gradually during operation. Otherwise, you can waste a lot of paint and ruin the surface of the car.
The adjusting screw acts as a limiter for the needle, which partially covers the inlet hole for the paint. Thus, it is convenient for the master to adjust the paint flow by opening the screw and pressing the trigger. In this case, operate only with pressure on the trigger.
Rules for using paint sprayers
When preparing a paint sprayer for work, first of all, check the spray heads, they must be clean, the holes of the material nozzle and the air cap must be coaxial. The end of the tip of the material nozzle should protrude somewhat from the air cap (for paint sprayers with an upper or lower paint pouring cup) or slightly recess into it (for paint sprayers with paint supplied under pressure). The axis of the side air holes must intersect the axis of the central hole of the head. When you press the trigger, the locking needle should move away quite freely and smoothly, and when it is released, it should tightly close the hole of the material nozzle. Oil seals, gaskets, seals of the air valve shut-off needle and head must be tightened sufficiently well to prevent paint from entering the air line or air from entering the paint line, as well as leakage of paint and varnish material during operation. When the trigger is pulled, the compressed air hole in the spray head must open before the material nozzle hole opens and paint begins to flow out. Otherwise, unsprayed drops of paint will inevitably be released when the spray gun is turned on and off.
Before starting work It is necessary to check that the spray gun is adjusted. To do this, perform a test application of paint and varnish material on a separate sheet.
After finishing work An appropriate solvent is passed through the paint sprayer and the hose through which the paint and varnish material is supplied for rinsing.
Washing is carried out until clean solvent appears from the spray gun. After washing the paint sprayer, its channels are blown with air, then the air cap removed from the body is washed in a solvent if its holes are clogged with paint. Thus, they are cleaned with a wooden pin or copper wire; it is prohibited to clean the holes with steel wire. During short breaks in work, especially when applying quick-drying paints and varnishes, it is advisable to place the head (item 2) of the paint sprayer in a tank (item 1) with a solvent (see figure), which protects the paintwork material from drying out in the nozzle, otherwise it is necessary to disassemble the spray gun. You need to lower the head into the tank so that the solvent does not get on the seals.
Rules for spray painting
The correct technique for performing spray painting jobs according to several simple rules allows you to increase productivity, improve the quality of coating, and minimize losses of paint and varnish material.
The main conditions for achieving coloring effects are:
1. Selecting the appropriate spray gun.
Depending on the size of the products to be painted, a spray gun of appropriate dimensions should be used. Small items and small surfaces should be painted with small-sized paint sprayers, as this will ensure economical consumption of paint and compressed air.
Large surfaces should be painted with large-sized sprayers that ensure high labor productivity.
2. Selecting appropriate nozzles for paint and air supply.
The type of nozzle for supplying paint depends on the type of paint and varnish material, as well as on its quantity, which must be applied to the surface (coating thickness) in accordance with technological requirements.
The type of air nozzle is determined by several factors, namely: the amount and pressure of compressed air, the dimensions of the products being painted, the type of paint and varnish material, the required painting speed and the method of applying paintwork materials.
3. Adjusting the spray gun, compressed air pressure and paint supply.
Before painting it is necessary to make adjustments:
- pressure of paint and varnish material;
- atomizing air pressure;
- width of the jet of sprayed paint.
Spray guns are equipped with an adjustment nut to reduce or increase the flow of material. It is recommended to install the needle in a position that ensures full opening of the nozzle to supply paint, and regulate the shape of the torch with air pressure. To regulate the atomizing air pressure, some spray guns are equipped with a spray air pressure regulator, while others are equipped with a reducer mounted between the air duct and the spray gun.
Too high atomizing air pressure causes excessive paint mist and paint reflection from the surface being painted, and reduces the coating thickness in the center of the print. Too low pressure causes the formation of a rough, uneven coating - “shagreen”.
The speed of movement of the paint sprayer over the surface to be painted depends on the amount of paintwork material coming out of the nozzle. In order to prevent the occurrence of local thickening of the coating, it is necessary to think through the sequence of strokes (movements) of the paint sprayer and, with the smallest number of such strokes, achieve complete coverage of the surface without twice overlapping the paint spray at any point.
The result of such a work plan should be: fast, free movement of the sprayer and obtaining a coating of uniform thickness without streaks and drips.
4. Spray gun stroke consists in its movement parallel to the painting plane at a certain distance, the axis of the spray gun should remain at right angles to this plane, and the distance from it to the spray head should be 20-25 cm.
The spray gun should be moved evenly from left to right and back along the entire length of the stroke so that the previous stripes (prints) of paintwork overlap the previous ones by 50%.
The shorter the distance between the spray gun and the surface to be painted, the thicker the coating. In order to prevent the occurrence of streaks and drips, the movement of the sprayer must be accelerated. Too large a distance leads to the formation of a “dry” coating - a rough one, as well as the formation of too much diffuse paint mist (see fig.)
The relationship between the speed of movement of the sprayer and the distance from the surface to be painted is easy to feel and a moderately skilled painter learns it very quickly.
The hand spray gun should be positioned parallel to the surface of the product. Obvious errors, such as the movement of the sprayer in an arc and in a vertical plane, are presented in the figure.
To obtain a uniform coating thickness, the first layer of paint and varnish material is applied in vertical stripes, and the second in horizontal stripes.
- The first strip is applied from top to bottom along line 1-2 to the end of the surface to be painted or to a certain horizontal line 2-3, then to apply each subsequent strip, the hand with the spray gun is moved to the right. At this moment, by lowering the trigger, the supply of paint and air is stopped, the second strip (section 3-4) is applied from bottom to top, etc. To obtain a continuous coating, it is necessary that the edge of the subsequent strip overlaps the applied paint strip by 5-8 mm.
When painting, do not move the spray guns in a wave or loop manner. The spray gun must be held perpendicular to the surface to be painted. If you hold it at an angle, the width of the print of the ink torch increases, and the thickness of the coating will be uneven. With the spray gun in a perpendicular position, the coating has almost the same thickness. Moving the spray gun is done by moving the body and arm, not the hand
When painting protruding parts and corners of products, the spray gun must be operated without moving the torch beyond the contour of the product.
The speed of movement of the paint sprayer should be uniform and within the range of 14-18 m/min.
The distance from the spray gun to the surface to be painted should be 200-250 mm depending on the viscosity of the paint and varnish material, a smaller distance for higher viscosity and a larger distance for low viscosity.
If the distance to the paint sprayer is greater than necessary, then the amount of paint and varnish material that does not reach the surface to be painted increases, and, consequently, its losses due to fogging increase. If the spray gun is located close to the surface to be painted, drips and unevenly covered areas will appear.
Starting and stopping the spray gun
The trigger is used to start and stop the spray gun. when this hook is returned in the direction of the handle, the paint output increases and therefore, during painting work, at the beginning of each stroke it is necessary to press it all the way and release it immediately before the end of the stroke.
The correct move should be carried out in the following way:
Painting the edges should begin by making two vertical strokes along the left and right edges.
Correct setting of the spray gun is the key to excellent results. The spray gun provides an even coating of the surface, without streaks and marks that arise during painting with a brush. A spray gun is an indispensable thing for those who care about comfort in their apartment. There are rules for setting up this device.
For getting desired result When working with a spray gun, you must configure it correctly.
Spray gun design and adjustment tasks
Modern models of spray guns have a similar structure. Their main elements are:
- paint tank;
- lever;
- paint supply regulator;
- air supply regulator;
- a nozzle on which holes are placed for breaking the paint;
- mechanism for regulating the spray pattern;
- material nozzle with diffuser and needle.
All modern models of spray guns are designed in such a way that, if necessary, you can easily adjust any parameters necessary for normal operation using three regulators.
The spray gun can be adjusted only after paint has been poured into the tank. To set up, you will need a surface on which to test the work. A section of wall with a sheet of Whatman paper attached to it is quite suitable.
The correct approach to setting up the spray gun determines the final result of the work. Fine tuning requires compliance with 4 basic conditions:
- paint preparation;
- installation of a torch of the required size;
- setting the correct air pressure;
- regulation of paint supply.
Compliance with all these conditions can guarantee excellent results. In addition, a surface painted with a properly adjusted spray gun looks smoother and dries faster, and the process itself is much easier and faster.
Return to contents
Preparing paint for work
Before setting up the spray gun, you should pay attention to preparing the paint. First of all, you need to properly mix the coloring matter and activator. Craftsmen and those who already have considerable experience in painting with a spray gun can measure the number of components by eye. Usually, the coloring component is poured in first, then the activator is gradually added to it - and so on until the desired consistency.
For beginners, it is better to hold off on experiments and dilute the composition, clearly measuring the number of components. How to do this and the necessary proportions - usually all this is written on the packaging. For example, if the marking is 2x1, then you should take 1 part of the activator and 2 parts of the mixture.
A measuring stick is usually used to mix volumes. But if you don’t have one, you can get by with a measuring container. In this case, a graduation is applied to the container, with its help it will be easier to measure the required portions of the mixture and activator.
An important factor that determines the quality of the finished surface is the level of viscosity of the composition. If we take it into account, work will go much faster, and the surface of the walls will acquire an attractive gloss. To achieve the required viscosity, you need to add a solvent. The volume of solvent is also indicated on the packaging. It is designated as follows: 2x1 + 10%. In this case, 2x1 is the ratio of the volumes of the mixture and the activator, and the volume of the solvent is 10% of the total volume of the mixture.
By paying due attention to paint preparation, you can be sure of a good result. But if you don’t have the relevant experience, you should refer to the instructions. Therefore, when choosing a mixture, you should pay attention not only to color and price. The packaging should have detailed guide on preparing material for work.
Return to contents
Torch size and paint supply adjustment
Adjusting the spray gun begins with setting the width of the torch. Optimal size the torch directly depends on the surface area that needs to be painted.
Full surface painting requires maximum torch. This will ensure optimal speed and uniform application. When dyeing different colors When there are fairly narrow color transitions, the width of the torch must be reduced and checked on whatman paper. Please note that along with reducing the width of the torch, it is necessary to reduce the air supply.
Once the spray width and optimum pressure are set, the paint flow can be adjusted. The adjustment screw must be tightened completely, then released 2 turns. You shouldn’t install a high feed rate right away: this will only ruin the surface and waste paint.
This can also lead to contamination of the spray booth and an unsightly appearance of the surface. Therefore, to begin with, it is better to set a low feed rate, and then, if necessary, increase it during the painting process.
The paint supply adjustment mechanism operates as follows: the movement of the steel needle is limited by a screw. Therefore, it cannot completely open the hole through which the paint comes out.
Return to contents
Pressure control
Adjusting the air pressure is a more difficult task. If this indicator is set correctly, the color uniformity will be maximum. The difficulty is that for each case this indicator is unique. Indicators in in this case serve:
- spray gun model;
- viscosity index;
- type of paintwork material (paint and varnish material).
Setting the optimal pressure in the spray gun is done using a regulator that is built into the handle or can be removable. In the first case, the pressure changes when the trigger is pulled. If you do not do this, then when you press the trigger, the pressure in the spray gun will increase sharply and the paint will spray unevenly. If the regulator is removable, then it must be opened completely in the place where the receiver connects to the hose. Then you need to pull the trigger and set the desired value.
The pressure required for proper operation of the spray gun is usually indicated in the accompanying documentation. But if documents are lost or for some other reason the pressure indicator is unknown, it can be determined experimentally.
To do this, you need to pour paint into the tank and open the regulators. We regulate the pressure: this indicator can be assessed using a short (1 second) injection onto the surface. The resulting print must be carefully examined, assessing all splashes, the size and shape of the droplets.
If the print resembles a pear or crescent moon, then the head or nozzle is faulty or possibly dirty. Flowing drops are produced due to insufficient pressure, and a number eight indicates that the pressure is excessive. You need to adjust the pressure until you get a well-defined mark on the sheet without smudges or compactions. Test injections should be made approximately 20 cm apart.
- traditional type (high pressure): it is recommended to set the value within 2.5-3.5 atm.;
- spray guns low pressure: recommended value - from 1.5 to 2.5 atm.
In addition, it is worth considering that for every 6 m of hose it is recommended to add 0.5 atm.
The correct choice of pressure and the correct setting of the spray gun allow you to obtain high-quality coating.
In order to understand how to paint with a spray gun and get a perfectly flat and smooth surface, you need some experience with this tool. It is also necessary to understand the technology of the process itself. Precautions should be taken. You only need to work in special glasses and a respirator with two filters.
It is necessary to prepare and properly workplace. It is best to carry out painting in a special chamber with good exhaust hood. However, when using water-based paint, any clean and ventilated area will do.
Install good lighting to better see all the smudges, unpainted areas and sagging. To do this, it is better to place the light source at a small angle to the surface to be painted. In addition, you should carefully clean the surface to be treated with fine-grained sandpaper, since the paint, which is applied using a spray, will reveal all its irregularities.
Preparing paint for work
You need to know how to properly dilute spray paint. It should be carefully filtered to remove lumps. Many paints have a rather thick consistency and therefore need to be thinned. What solvent and how much of it is needed to thin the paint is indicated on the can.
In order to determine the thickness of the paint, you need to pour it into a container and mix it with a stick. If a drop flows from the stick at intervals of about a second, then the viscosity is normal. After the spray gun bottle is filled, you need to start painting. However, there is no need to paint the car itself right away. It's best to start by practicing on a piece of plywood or iron.
It is also necessary to control and properly regulate the mixture of paint and air. For this purpose, the spray gun has special handles that control such processes. It is worth remembering that one adjustment affects the other.
Preparing paint for a spray gun necessary procedure. In order for the paint to be ready for filling into the spray gun, it is necessary to add either a solvent or an activator (hardener, accelerator) to it.
It is best to follow the instructions given on the paint can if you have no experience in this matter. If it is written that the activator should be added in a two to one ratio, then you need to take one part of the activator and mix it with two parts of paint.
In addition to the activator, the paint may need to be diluted with a solvent. If the label says 2 to 1 plus 10 percent, this means that to one part of the activator you need to add two parts of paint and 10% solvent, depending on the volume of the working solution.
How to set up the instrument
Correct setting of the spray gun is very important for easier and most importantly high-quality painting vehicle. This process must be approached comprehensively, since all stages of the spray gun adjustment process are interconnected. Before setting up the spray gun, you need to check 4 main parameters.
- Prepare all necessary materials.
- Mix the selected paint and varnish material with the necessary activators in the correct proportions.
- Next you need to adjust the torch.
- Set the desired pressure level and determine the intensity of paint supply. All these parameters must be adjusted carefully to ensure even and correct paint spraying.
Before setting up the spray gun, you need to find out what elements it consists of. This tool consists of a paint filling cup, which has a capacity of 100 to 250 ml with a replaceable filter, a nozzle with a stainless steel needle and a pneumatic diffuser, and a handle with a trigger. There are also three regulators: for the torch, for supplying paint and for pumping air.
After pouring the filtered paint, you need to test the spray gun on a sheet of cardboard or paper. If you need to paint a relatively small area of the car and you need spot spraying, it is better to set a small spray width.
If painting occurs on large surfaces, then it is best to work with a wide torch. This will make the process faster and the coating will become uniform. It should be remembered that the smaller the torch size, the less air supply should be.
Main malfunctions during operation of the spray gun.
You need to know how to properly configure the spray gun to understand whether it works.
- The pressure in the spray gun must be set individually depending on the model and the paint that is used (its viscosity).
- The spray gun should be kept 30 cm from the surface to be painted. You need to make a couple of sharp short-term bursts of paint to evaluate the result.
- If thick spots of paint remain on the surface, this means that the pressure is quite low.
- A spot that has an irregular shape, for example, in the form of a crescent, indicates a malfunction of the nozzle, nozzle, or spray gun head.
- If the paint print has the correct round shape and the paint is distributed evenly and supplied continuously, then the air is supplied optimally.
- To adjust the air supply, remember that the regulators can be built-in or removable.
How to adjust a spray gun with a removable regulator? To control the pressure, you need to run the regulator at full power where the receiver connects to the hose. For an inline regulator, the pressure is changed only by keeping the trigger pressed. This is necessary in order to avoid sudden sharp changes air supply when starting work.
Adjustment of the spray gun is necessary before each painting. . The paint supply must begin with a small injection. This will save paint. The adjusting screw should be tightened completely and then loosened slightly. After all, the more you tighten the screw, the smaller the hole in the needle becomes for feeding paint into it. So, by pressing the trigger with varying strength and slowly loosening the regulator, you can gradually achieve a good and suitable level of paint flow.
Problems with the instrument
The spray gun, like any tool, needs periodic cleaning and careful maintenance. It may become clogged and begin to malfunction. The shape of the torch will help you understand why the spray gun does not work. Also, testing the color spot can help you configure the instrument correctly and understand what is wrong with it.
It should be remembered that the ideal is considered to be a paint print with a regular rounded shape, which was applied without sharp transitions, smudges, or large drops.
If there is any deviation from this, it means that the spray gun was adjusted incorrectly or some part is faulty.
- When spraying paint to the side, you need to clean or replace the air cap or nozzle.
- A bent color spot indicates a clogged air cap.
- A thick flame indicates a clogged air vent or one of the air cap wing channels.
- If there is a color spot in the shape of a figure eight, there is a suspicion of low paint density, or there is very high pressure in the air chamber of the instrument.
- If the spot is very dense in the middle, it means that the paint is quite thick, or the pressure in the spray gun is very low.
If the paint is applied unevenly, there are several reasons.
- Does not work, or the nozzle is poorly secured,
- there is a lot of paint in the tank,
- the instrument is strongly inclined,
- the channels that supply paint to the nozzle are dirty,
- The needle is faulty because it is clogged with paint particles or its adjustment screw is not tightened tightly.
Instrument care
All parts of the paint sprayer that interact with paint and varnish materials must be cleaned using a solvent immediately after the procedure. If the instrument is used frequently, then you need to completely disassemble it and wash it at least once a week.
If there is lubricant in the kit, it is worth periodically treating the parts of the spray gun with its help. If lubricant is not provided, it is better to purchase it in special stores. In addition, all seals, needles, gaskets, and air cap require replacement as they wear out, but at least once a year.
You need to know how to clean the spray gun and all its individual parts . The tank ventilation hole should be cleaned immediately after use. Otherwise, even the smallest particle leads to the fact that the paint will constantly flow incorrectly, interrupting and laying down unevenly.
Before putting the spray gun away for a long time, all its parts should be washed and cleaned.
All major malfunctions of the spray gun occur due to its clogging with particles of dried paint. Therefore, you need to clean the instrument thoroughly. First, you need to disconnect the paint tank and drain the remaining paint into a container. Press the trigger and blow out the remaining paint in the supply tube.
Next, you should pour solvent into the container (about half of its volume) and spray it for ten seconds. Then remove the cylinder and blow out the supply tube. This process must be done until completely pure solvent comes out of the sprayer.
It should be remembered that paint made with water can cause destruction of aluminum parts. That is why it is necessary to ensure that the parts are well cleaned and dried. If the lever is not working well, when it is too tight, you need to either change the air valve stem, clean the needle, change the paint head, or loosen the nut.
If there is a defect in the air cap holes on the side, they should be cleaned. If the torch moves away from the axis of the tool, then you need to clean (change) the pneumatic head.
If the torch produces an incorrect asymmetrical spot, it means that the painting head is faulty or the nozzle is damaged. The center hole of the air cap may also be damaged. We need to change them.
If the spray gun does not spray paint, this may be due to a lack of pressure, a clogged nozzle, blocking the access of paint or air, or a faulty needle. It is necessary to adjust the pressure indicators, then you can try to clean the needle, nozzle, and check the paint flow process. If such measures do not bring results, it is best to purchase a new needle and head.
If the torch operates intermittently, then most likely the nozzle cone is faulty, the gaskets are worn out or damaged. They need to be replaced.
This way you can get rid of more paint. However, to completely clean the entire spray gun, you must completely disassemble it, following the manufacturer's instructions. After the disassembly process, all parts are placed in a jar filled with solvent.
Cleaning of the supply channels is carried out using a nylon brush. The air cap and nozzle should be cleaned very well, for example with a toothbrush. Before assembling the tool, lubricate the nozzle, fluid needle, and threads on the air cap with Vaseline. After assembly, wipe the entire spray gun soft cloth soaked in solvent.
How to paint a car correctly
Before setting up a spray gun for painting a car, you should study the entire algorithm for such actions. In order to paint your car efficiently, you must first test the nozzle. To do this, you need to set the torch to spray in a horizontal position and open the air supply screw to full power.
Then adjust the paint flow screw so that the next time you press the trigger you get exactly correct form color spot. To obtain a thin and uniform final layer, it is necessary to carry out local circular spraying without using spraying in one direction.
Paint should be applied evenly circular movements and perpendicular to the surface with a radius of less than 8 cm. The trigger should be released after each local spraying, which will ensure the quality of painting.
To begin with, it is better to paint small and barely noticeable parts, because later it will be much more difficult to paint them. Before finishing painting, you should make sure that the base layer has already dried and become uniform in structure.
To accurately maintain the proportions, a measuring ruler is needed. You can also use a special plastic vessel, which should be graduated evenly. This will allow you to accurately mark the portion of paint, hardener and solvent.
When painting a car with a metallic effect or with special protection against exposure to factors external environment A two-layer coating is required. First, apply the base paint, and then acrylic varnish.
All parts of the composition must be mixed according to the instructions, which should be indicated on the pack. Activation is not needed for the paint, since it dries under the influence of the evaporating solvent.
Feed regulation is based on the fact that the adjustment screw acts as a limiter under the action of a needle made of stainless steel. Due to this design, the needle does not completely cover the outlet hole for paints and varnishes.
With this design, the person working with this tool has the opportunity to adapt by opening the screw to full power and manually pressing the trigger with varying strength.
To avoid paint smudges at the edges of the surface, it is better to press the trigger of the spray gun before moving it along the part. Then, having started the transition, do not release the trigger until it is completely completed.
When painting the inner corner, to prevent paint accumulation, you need to direct the center of the torch, shifting it to one side. Painting is done in two steps, once for each side of the corner. Sometimes when painting interior corners, the trim will create a hazy cloud. To avoid this, it is necessary to reduce the paint supply and air pressure.
When painting outside corners, it is almost impossible to prevent excess paint from appearing on an already painted surface. It is better to paint all sides of the corner at one time. You need to start painting the corner from the top.
If you follow all the points listed above, then there should be no problems when painting. The surface should be flat and smooth. If you do not follow them, then it is unlikely that you will be able to avoid unevenness, and the coating will take much longer to dry.
Let's find out how to set up the spray gun so that the layer of coating being laid is as even as possible. After all, it doesn’t matter how high-tech and expensive the sprayer you purchased, without correct settings tool, the quality of the painting work will be unsatisfactory.
However, before setting up the spray gun, let’s try to understand what this device is.
It’s easy to set up and use the sprayer for its intended purpose.
Devices for applying coatings by spraying are presented on the market in wide range. The difference between the presented modifications lies in both price and the principle of paint application.
The work of painting sprayers is carried out in two stages:
- the paint breaks into tiny fragments;
- a torch shape is formed.
In the photo - types of torch in accordance with the type of spray gun
All sprayers on the market can be divided into three main categories according to their operating parameters:
- Conventional systems (CONV) – characterized by high pressure in the spray head up to 3 bar.
- High volume, low pressure (HVLP) devices up to 0.7 bar.
- Low volume and low pressure (LVLP) devices up to 1.2 bar.
Regardless of the design of the spray gun, a torch of compressed air and paint and varnish materials is formed in the spray head. Leaving the spray head, the mixture in the form of a torch is distributed over a certain distance, and when it hits the surface, it forms a paint coating.
For household use, it is advisable to use large-volume, low-pressure paint guns, since they are more versatile in terms of the paint used and their price is more affordable compared to the cost of devices of other designs.
Preparing the room for the test
Before setting up the spray gun correctly, you need to prepare optimal conditions for testing.
It is advisable to experiment with applying paint and varnish in a workshop or garage, having previously cleared the room of various things and objects within a radius of 2 meters. We will try the spraying parameters on a vertical plane, for example on a wall or on a garage door.
In order not to unnecessarily dirty the surfaces, you can attach some unnecessary material measuring 2 by 1 meter to the wall or to the gate with your own hands. It doesn’t matter whether it’s old paper or plastic film - everything will do, because we’re not experimenting with color, but with hiding power.
So, the conditions for test staining are ready, let's start making adjustments.
Spray gun device
A pneumatic paint sprayer (spray gun) is a technically simple device in which compressed air, when supplied from a nozzle, sprays paint materials. Let's consider the design features of the painting tool shown in this figure.
Paint gun diagram
Here we see a traditional paint gun consisting of the following structural elements:
- paint tank;
- spray body;
- a spring that drives the needle;
- adjustment bolt for needle adjustment;
- fitting for attaching a pressure gauge and an air supply hose;
- spring holding the valve;
- kernel;
- mixture feed lever;
- a needle that limits the flow of the mixture;
- nozzle;
- nozzle casing (head);
- connecting adapter;
- fastening nut.
Modern spray gun models supply paintwork materials from the tank to the nozzle. The mixture is supplied by compressed air, which is pumped by a pump or compressor.
Most tools for setting parameters are equipped with adjusting screws. Some high-tech modifications are equipped with an electronic torch adjustment system.
Diagram of an electronically controlled paint gun
Depending on the shape, the nozzle can be narrow-jet or flat-jet. That is, by choosing a suitable nozzle, you can achieve paint spraying in a strip of a given width.
The paint filling cup (tank) of the spray gun is usually made of transparent plastic. These tanks allow you to see how paint is being used.
General rules for adjusting the spray gun
In principle, the settings for paint guns are similar, regardless of the modification used. Therefore, let's look at the general rules.
The photo shows the location of the adjusting screws
The adjusting bolts are located in the following order:
- adjusting the air supply from below,
- adjusting the supply of paint and varnish materials in the rear part of the gun handle;
- Adjustment of the torch parameters is again located behind the handle or on the side.
Symptoms of problems and solutions
As a rule, it is difficult to make a mistake with the location of the controls, since the design of the pistols is standard.
But, just in case, read the instructions for the device you purchased.
- First of all, everything set the regulators to minimum. As a result, when you press the mixture feed lever, you will practically not hear the hiss of escaping air, and a layer of paint will not appear on the test surface.
- Next, unscrew the adjusting bolt on the air supply from the compressor by 2-3 turns, so that the arrow on the pressure gauge is located between 1 and 2 atmospheres. There is no need to set the maximum pressure from the very beginning, since we will adjust this parameter later in combination with other adjustments.
- So, We gave the air pressure and when we press the mixture supply lever we hear a characteristic hissing. Now open the adjusting screw responsible for the paint supply by 1-2 turns, and immediately open the torch by one turn.
- Trying to paint. We place the gun at a distance of 25-30 cm from the test surface and briefly press the lever to spray the paint.
In the photo - the result of a close position of the sprayer - “orange”
Important: By placing the spray gun closer than 20 cm, you will get an orange-colored coating texture. Placing the gun further than 30 cm from the surface will result in insufficient coverage. As a result, you will have to apply paintwork in a large number of layers, which will result in excess paint consumption.
- If paint comes out of the nozzle but does not reach the test surface, add air pressure. If the air from the gun bends the film attached to the wall, but does not paint it, add paint.
If the problem is not solved, increase the torch. By following these tips, you can find the setting that will get the paint onto the test surface.
- Now Let's start adjusting the shape of the trace of the applied paint.
Features of torch adjustment
An optimally tuned gun leaves paint in the shape of a vertical oval. Moreover, the shape of the oval should be the same in the upper and lower parts.
It may be that the oval is uneven and Bottom part extended. There are two reasons for this phenomenon.
First of all, try to hold the gun perpendicular to the surface being painted. If you hold the spray gun level, but the oval is still narrowed downwards, in all likelihood you need to reduce the paint supply.
If you do not do this and start painting, there is a high probability that multiple smudges will appear, which will not be easy to remove from the painted surface.
- By almost completely removing the torch, we get a dot-shaped coloring. Such an add-on is necessary if we apply coatings to pipes or process internal cavities on any complex parts. Having removed the torch before painting in the shape of a dot, you should not linger in one place for a long time, since, again, there is a high probability of smudges.
When working with such a torch add-on, we paint in two layers. The principle is as follows: draw a line. Then, we place the next line so that it falls halfway on the previous line. This method allows you to achieve good coverage with low paint consumption and no smudges.
Important: Often it is not possible to adjust the spray gun properly due to the incorrect consistency of the paintwork material. When diluting the paint, make it so liquid that it flows like water, but at the same time paints the walls of the jar or vessel in which mixing takes place.
Conclusion
As you can see, the instructions for setting up the spray gun do not seem particularly complicated. Having a technically sound tool, paint diluted to the required consistency, and a little patience, you will certainly achieve optimal quality paintwork (see also the article “Spray gun for painting a house”).
