Do-it-yourself spray gun repair

In detail: do-it-yourself spray gun repair from a real master for the site my.housecope.com.

For uniform spraying of various paints and varnishes (paintwork materials), primers, liquid putties, protective compounds and impregnations, painting devices called spray guns are used. This equipment may differ from each other not only in the device, but also in the principle of operation, which affects the quality of the applied coating.

Most often, both in the household and in the professional sphere, electric and pneumatic spray guns with different positions of the tanks are used. Also, these devices can have a pressure gauge built into the handle or connected to it.

The electric spray gun consists of a plastic or aluminum housing that houses the following items (see picture below).

Electromagnet. Works in impulse mode, pulling the bar.
Oscillating bar... It is attracted by a magnet and pushes the piston forward.
Ink supply regulator... Limits the mobility of the oscillating bar.
Nozzle. Sprays paintwork materials or other compounds.
Cylinder... It is the pump body in which the piston moves.
Valve... Opens and closes the paint supply.
Suction tube... Designed for suction of paintwork materials. A filter can be installed at the end of the tube.
Piston spring... After the piston moves forward, it returns it (together with the bar) to its original position.
Piston... Sucks in and pushes paintwork from the spray gun.

Also on the device there is a power button, a fitting for connecting a tank.

Spray gun working according to the following principle... After pressing the start button, current is supplied to the electromagnet (1) in short pulses. At the same time, the electromagnet then attracts the bar (2), then releases it. The range of movement of the bar, and therefore the piston, is regulated by the screw (3). The bar, pressing on the piston rod (9), sets it in motion. The reciprocating movements of the piston suck in the paintwork material from the tank and push the composition towards the valve (6). When the piston moves forward, the valve opens and passes the paint to the nozzle (4), through which it is sprayed. With the reverse movement of the piston, which is provided by the expanding spring (8), the valve closes, and the paintwork material is sucked from the tank through the tube (7). Further, the process is repeated.

Video (click to play).

Important! Electric spray guns also include models with an external compressor. In this case, the device of the spray gun is slightly different, and the principle of operation of a spray gun is similar to the operation of a pneumatic spray gun.

The tool is powered by compressed air from a compressor. Below is a sectional diagram showing the construction of the device.

The pneumatic spray gun has the following elements in its design (see diagram above).

Spray head together with a nozzle (nozzle). The spray gun nozzle and air cap are removable. They can have different outlet diameters, which are selected in accordance with the viscosity of the composition to be sprayed.
Tank for paint... It is made of either plastic or metal, and can be installed both at the top of the tool and at the bottom.
Spray gun body... Serves as the basis in which all the elements of the device are installed.
Locking screw. Regulates the intensity of the ink supply by limiting or increasing the movement of the locking needle. Some spray gun models have an air regulator.
Lever... Designed for comfortable holding of the tool in hand.
Pad. Serves as a seal in the mechanism that moves the needle.
Trigger trigger... Drives the shut-off needle.
Locking needle... Opens or closes the nozzle opening.

The work of the pneumatic spray gun is as follows. With a slight pull on the trigger, the air valve opens and air begins to flow through a separate channel into the air cap. With further pressure on the lever, the needle moves back, opening the nozzle, through which paint begins to flow. The paint, mixing with the air flow in the air cap, is crushed into small particles, forming an aerosol torch.

For convenient work with a paint sprayer, use a special wall holder.

Also widely used by painters stand for spray gun, which you can easily do with your own hands.

Spray gun device with top tank, as well as the principle of its operation, was discussed above. The only thing that needs to be clarified is the way the paintwork material is fed into the tool body. Since the paint container is located at the top of the appliance, it flows naturally to the shut-off needle due to the force of gravity.

Spray gun device with bottom tank differs only in the location of the latter. The intake of paint from it occurs due to the vacuum created by the air flow inside the device. In the future, the operation of the spray gun does not differ from the operation of the device with the upper arrangement of the container.

In addition, not so long ago on the market of equipment for applying paintwork materials appeared vacuum tanks... They are successfully used instead of standard spray cans. The vacuum tank is a hard glass-flask with a hole at the bottom, into which a soft glass with a lid is inserted. There is a scale on the flask, by which it is convenient to determine the amount of paint.

The advantage of vacuum tanks is that they allow the spray gun to operate in any position. Regardless of how the device is turned, upward or downward, the colorant still enters the gun due to the vacuum formed in the soft glass. In this case, the glass is deformed, and the paint is squeezed out of it completely.

If you look at the body of a modern paint sprayer, you can see 2 or 3 adjusting screws. The first regulator can be located either on the top or on the side of the housing, such as for SATA spray guns (see illustration below). He is responsible for the shape and size of the aerosol torch.

The second screw allows you to adjust the range of movement of the needle, which depends on the amount of paintwork supplied to the nozzle. Some spray gun models also have a third regulator. It can be used to regulate the air supply to the tool.

Setting up the spray gun means setting the correct material-air balance. By adjusting the optimal ratio, you can achieve the ideal shape of the aerosol spray, which will promote uniform spray of the composition onto the surface to be treated.

Important! The parameter of the inlet pressure is indicated by the manufacturer in those. the documentation for the device and is standardized.

The adjustment of the inlet pressure, ideally, should be done using a regulator with a built-in pressure gauge that is connected to the handle of the instrument. This is explained by the fact that the pressure loss in the line can reach 1 bar and higher. The longer the duct and the more bends it has, the greater the pressure loss. Also, this parameter is influenced by the installed filters and moisture separators.

Adjusting a spray gun with an upper tank with an installed regulator and a pressure gauge is not difficult:

first, unscrew as much as possible the adjusting screw (1) (see figure below), which is responsible for the air supply;

further, the torch shape and size regulator is unscrewed (2);
after unscrewing the screws, pull the trigger (3), after which the air supply will start;
at the last stage, set the value on the pressure gauge (4) corresponding to the recommended one by turning the pressure regulator.

Some “advanced” spray gun models have a built-in electronic pressure gauge.

It is even easier to adjust the spray gun with the built-in electronic pressure gauge (see figure below).

Open the torch regulator as far as possible.
Pull the trigger.
Referring to the readings of the pressure gauge, turn the air regulator until the pressure level at the inlet to the device reaches the recommended values.

In the case when there is a pressure gauge without a regulator on the handle of the spray gun, then the spray gun can be correctly adjusted as follows (see the figure below).

Unscrew the air regulator to the maximum.
Unscrew the torch regulator as much as possible.
Next, pull the trigger to supply air to the gun.
Adjust the pressure using a reducer or filter group installed at the compressor outlet, referring to the readings of the pressure gauge.

If the spray gun is not equipped with a pressure gauge, then a rough, approximate adjustment of the device can be made. using a compressor reducer, taking into account the pressure loss in the line.

You can set up a spray gun for painting, if it does not have a measuring device, using the following method (see the figure below).

Open gun air supply.
Open the torch width adjuster.
Pull the trigger to open the air supply.
Using a reducer located at the compressor outlet, set the pressure taking into account its losses in the line. That is, the pressure on the pressure gauge should be 0.6 bar higher than the recommended pressure, provided that a 10 m hose with an inner diameter of 9 mm is connected to the device. For a more accurate calculation, take into account the presence of filters installed between the spray gun and the compressor.

Sometimes situations arise when there are no instructions for the device, or it is impossible to determine its manufacturer in order to find out what pressure is needed for the spray gun. Knowing the inlet pressure required for such an unknown tool can only be experienced.

First of all, you should pick up Paintwork materials of standard viscosity and pour it into the tank.
Next, you need to unscrew all the regulators on the instrument and use the adjustment screw on the pressure gauge to “experiment” with the pressure. It is required to achieve such a value at which a uniform torch print will appear on the painted surface. In this case, the instrument should be kept at a distance of 15 cm from the surface prepared for the test.
When the desired result is achieved, record the value of the inlet pressure. This will be the working pressure for this device.

Important! You should be aware that most of the cheap, unknown origin of spray guns, for normal operation, require an increased air consumption, more than 200 liters per minute. Accordingly, not every compressor will be able to provide such a tool with the required amount of compressed air, which will affect the result of painting.

It is no secret that the efficiency of coating with a paint sprayer largely depends on the state of the torch. The larger its size, and the higher the density of the aerosol, the more evenly the coating is applied to the surface with a small number of passes. But in some cases it is necessary to set a small torch size, for example, if you want to coat small parts or paint in hard-to-reach places.

Torch size is easy to adjust: by turning the screw towards the “+” sign, the spray width increases, and, conversely, when the regulator moves towards the “-” sign, the spray zone decreases.

For standard repairs, various coatings and body painting, it is recommended to open the material regulator fully. Usually this 3-4 turns of the adjusting screw... In this case, the nozzle should come off completely after pressing the trigger.

An important role in setting up a spray gun is played by the diameter of the nozzle. It is matched to the density of the composition to be used for spraying. Below is a table to help you quickly determine which nozzle diameter is required for different coatings.

Despite its simple design, the spray gun is still susceptible to breakage. Frequent spray gun malfunctions can be counted on the fingers.

This happens in the following situations.

The air pressure in the system is extremely low. The compressor must be adjusted to correct the problem.
Ink flow is interrupted due to clogged needle and nozzle. It is necessary to disassemble the spray gun and clean the listed items.
Needle or nozzle is damaged. Replacement parts required.

Several malfunctions can cause the spray gun to spit.

Air cap not tightened properly. It is required to screw the part well.
The viscosity of the paint does not match the air pressure. It is necessary to achieve an acceptable pressure-viscosity ratio.
The paint is too thick. It is necessary to prepare the paint of a lesser density.
Dye reservoir breather clogged. It is necessary to remove the plug and clean the hole in it.
The pressure in the receiver has dropped below normal. It is required in the compressor settings to set the lower pressure threshold corresponding to the performance of the spray gun.

If the torch of sprayed paint moves away from the gun, then the reasons for this may be the following.

Clogged air cap side holes. It is required to remove the head and clean it.
Damage to the side holes of the air cap. The damaged part must be replaced.

In this case, the problem may be caused by the following malfunctions.

Clogged nozzle. Repairing the spray gun in this case consists in removing the nozzle and cleaning its hole.
Damage to the nozzle. Part replacement required.
Clogging of the air cap, namely, its center hole. Remove the air cap, rinse and clean it.
Damage to the center hole of the air cap. This part requires replacement.

Construction and painting tools are gradually being improved. The usual brush and roller displaces the spray gun, which allows you to evenly paint large areas in a short time. The device is easy to use, but, like any technique, it sometimes fails and stops performing its functions. What if the spray gun is not spraying paint as needed? Why, instead of a uniform ejection of paint from the nozzle, "spits" fly out or just air blows?

To deal with these issues, you need to decide on the types of devices. There are two types of spray guns.

with the upper location of the tank, when the colorant enters the nozzle under the action of gravity and its supply is regulated by changing the air pressure;
with a bottom tank, when the container is attached from below, the solution is pumped into the nozzle using compressed air.

Also called electric. Sprays the colorant using the pump built into it.

Both of these varieties are very different from each other, and with outwardly identical malfunctions, repairing a hand-held spray gun will be very different from repairing an electric spray gun.

Regardless of the principle of operation of the painting mechanism, before proceeding with diagnostics and troubleshooting, the following tools and spare parts must be prepared:

a set of wrenches of various sizes;
pliers;
screwdriver;
repair kit and other sets of spare parts.

A spare parts store for repair and construction equipment will be able to offer several options for repair kits for troubleshooting problems with spray guns. This could be:

A standard repair kit consisting of several bolts and rubber seals (it is better to stock up on such repair kits in advance because the seals quickly deteriorate under the influence of dyes).
Specialized repair kit. The kit includes spare parts for spray guns necessary to fix a specific problem or replace a failed part.

With your own hands, using a set of tools at hand, you can eliminate most of the problems with spray guns by simply cleaning the nozzle or installing replacement parts instead of those that have become unusable.

The following malfunctions may occur with hand spray guns:

The pump has stopped sucking in paint. The reason for this can only be a pump cuff that has lost its qualities. It can be softened in oil (if it is dry) or a replaceable one can be installed (if worn out).

The spray bottle spits out uneven streams of paint. This occurs when the spray gun nozzle has an outlet that is too large (greater than 0.7 mm) due to a broken washer. In order to correct the problem, the washer must be replaced using a repair kit.

Paint leaks from the crane of the fishing rod. There can be two reasons for the malfunction:

The tap is badly ground in. It is not difficult to fix this problem with your own hands - just grind the faucet with the help of tools.
Looseness of the spring on the tap. It must be tightened or replaced using the necessary tools from the repair kit.

On electric spray guns, unlike manual ones, not all problems that arise can be eliminated by hand.Some of them will require the services of an electrician to repair.You can fix the following problems with your own hands:To eliminate the following problems in the operation of the electric spray gun, you will need to contact the services of an electrical equipment repairman:

When the device is turned on, no noise is heard from the operation of the electric motor. This happens if the fuses are blown or a breaker breaks.

When touching the unit connected to the mains, current discharges are felt. In this case, it is life-threatening to use the device; it must be returned for repair immediately. The cause of the breakdown, most likely, is the short circuit of the parts responsible for conducting the current.

With a strong heating of the body of the device during operation, timely repairs will prevent wear of the parts of the electric motor, which occurs due to insufficient lubrication between them.

The unit works, but the pressure gauge does not indicate that there is pressure. The cause may be a malfunction of the electric pump or pressure gauge.

A spray bottle is a complex tool that requires careful handling. In order for it to be able to work for a long time without breakdowns, the following rules for caring for the device must be observed:

Clean immediately after finishing painting. For this purpose, the tank of the device, after removing the coloring material, is filled with a solvent having a composition similar to the used dye, and then the device is turned on and used on an unnecessary surface. The pressurized contents of the tank will do a good cleaning of all valves and hoses.

Never use a solvent that could cause a "chemical conflict" with the staining solution being used. Curdled paint residues can damage the mechanism.

After completing the flushing, the device must be well purged, and the container must be left open for a short time to evaporate the remaining solvent.

The paint sprayer with the coloring composition inside can be left only for a short time, but before that, take the following measures to prevent the composition from drying out: tighten the needle adjuster as far as it will go and tightly close the hole to prevent air from entering the tank.

Before refueling, to remove condensation or accumulated dust, the spray gun must be thoroughly blown out.

Low Pressure AOND Electric Sprayer

The most common parameter that people pay attention to when requesting a tool for painting work is pressure, and they are all classified as low, medium and high pressure devices.... It is very important to take into account that the quality of the atomizer is influenced not by its power, but by the correct selection according to any parameter for a specific case, that is, in different situations, different parameters are most acceptable. Of course, at home it is quite difficult to have several units of different calibers available, but given the needs, you can find the golden mean.
At home, with small amounts of work, as well as if it is necessary to frequently change paintwork materials, use low pressure guns from 2 to 5 atmospheres or bar (1 bar is equal to 0.986923267 atmospheres)... This is quite enough not only for DIY repair of walls and ceilings, but also for painting a car, motorcycle, moped, from spare parts and so on. But in such cases, rare paintwork materials are used, since this pressure is not enough to spray viscous liquids.

PILOT Maxi MD medium pressure gun (inlet 8 bar, outlet 0.7 bar)

Medium pressure gun PILOT Maxi MD, spray gun nozzle V1161505143 - 1.4 mm, operating pressure 8 bar at the supply and 0.7 bar at the outlet of the nozzle is used for finishing painting work, although it can be adjusted to almost any possibilities... Nevertheless, if there is a need for frequent replacement of paintwork materials, then such units are unprofitable to use - losses almost double.

High pressure spray gun. Adapted to GRACo, WIWA, WAGNER, KREMLIN, TITAN nozzles

On construction sites, in spray booths, as well as for thick (viscous) paintwork materials, high-pressure units are used, as a rule, the spray gun nozzle is 4 mm, although it may be less... It is noteworthy that such sprayers, in the absence of a pressure control unit, are used only for long-term painting processes, since with frequent changes of paintwork materials or workpieces, material overruns can reach 60%.

All Visible Airless Sprayer Components

In addition, the tank for the spray gun can be located at the bottom or top, which changes the paint supply scheme, and sprayers are pneumatic and airless, manual and electric.... All of these parameters will certainly affect the spraying process, the degree of contamination and wear of the spray gun.
Also, the service life and repair methods will depend on the pressure regulator (if any), or rather, on its location, and it may turn out to be:

Built into a pistol;
Removable unit attached to the pistol handle;
On the compressor, and the spray gun hose is connected downstream.

Pneumatic low pressure sprayer Caliber EKRP-400 / 1.8

We will not be able to consider the maintenance and repair of the spray gun in relation to each of the above parameters, therefore, as an example, we will take a pneumatic low pressure spray gun Caliber EKRP-400 / 1.8 as an example.

The biggest problem for such a sprayer, and for others too, is alkyd paints, if you forget, do not count the time, or simply do not consider it necessary, to clean and wash the gun after each use. This desolation leads to problems such as blockages, uneven spraying, and so on.

Disassembled valve

All spare parts for spray guns are subject to cleaning and washing, since they are practically "overgrown" with paint, which at first glance and even to the touch seems to be monolithic, but all these layers are washed off with solvent or gasoline.

Perhaps, the valve creates the most problems - it dries to the cylinder and it is almost impossible to move it, but here, too, solvents come to the rescue, which weaken the dried layer of paintwork materials, after which you can start cleaning. The most basic thing here, as with a surgeon - “do no harm” - you need to act carefully so as not to break this small detail.

This is how the spray gun nozzle is cleaned

In the formation of a torch, which determines the overall quality of painting with this tool, the main mission is performed by the needle, nozzles and nozzle (nozzle), which also clog no less than the valve.

And again you have to deal with small parts (see photo above) that need to be cleaned with a solvent and a brush, but here you need to be extremely careful not to scratch the nozzle itself, otherwise such grooves will serve as a place for the paintwork material to settle, which will lead to shape distortion torch.

Recommendation. For the best possible handling, this manual assumes the use of specially designed SATA needles and SATA brushes that will not scratch the nozzle.

In addition, the water separator for the spray gun can become very clogged, it is also a filter for the spray gun through which paintwork materials pass and for cleaning you can use all the same tools and materials - a brush, a needle and a solvent, only, of course, it is advisable to use them from SATA.

In addition, it is important that the paints and varnishes that enter the spray nozzle are clean, without lumps, and for this the tank must always be clean. The fact is that the paint frozen on its walls will peel off and mix with the liquid in any case, getting into the conductive parts.

Also, when servicing, do not forget about the pressure gauge for the spray gun and the pressure regulator, if any. There, too, there should not be dried layers of paint and varnish materials, as this leads to failures in their supply and, as a result, to poor-quality finishing. If you remember how the gun was when you brought it from the store, then try to make it look exactly the same after years of work - clean and well-groomed.

After cleaning the atomizer, you need to reassemble it in the same order in which you disassembled it, but do this after all parts are completely dry (you can dry it with a hairdryer). All rubbing parts, including the gun trigger stem and needles, should be lubricated with a non-silicone grease (learn how to use the gun here).

When you have to cover many square meters with enamel, experienced comrades, of course, will advise you to use an electric spray gun.This section will help you get started with this tool or expand your existing knowledge.It is hard to imagine a large-scale renovation, and even more so construction without painting. Moreover, today more and more surfaces have begun to trust paint. There are many reasons for this. For example, thanks to modern materials, the walls are easy to clean and always ready for your creativity. It is on such a finish that vinyl stickers or art painting fit well. Even wallpaper is covered with paint today. Ceilings are also less and less whitewashed, and if this is not a suspended structure, then most likely you would prefer to paint it. Image - DIY spray gun repair

What else might require a fair wave of the brush? Of course the floor! If you have a flooring made of solid wood, then it is a sin to remove it and lay parquet or laminate, usually restoration is done. This is a troublesome business: sanding, scraping and so on - but it all ends with nothing more than painting. Whether it is varnish or paint, you will have to walk the entire area repeatedly. Agree, it's not easy to do this with your own hands. During the renovation, not only the wooden floor is restored, but also the doors from the solid wood. Here the task is further complicated by the fact that you need to apply the finish evenly, because you see all this every day and uneven brush strokes or a pile forgotten in the thickness of the paint do not cause delight at all.

As you can see, the repair is burdened with a huge amount of painting work, and if you turn to specialists, you will not find a single team that would do it with a brush. Even paint rollers are rarely used, except for decorative finishes, when you need to create a certain surface texture. And if you are going to do everything with your own hands, then all the more the paint gun, which has been adopted by professionals for a long time, will greatly facilitate your task.... Our goal is to tell everything about it and its capabilities, as well as the features of the device and repair.

Naturally, the first thing you did, deciding to buy yourself such an assistant for repairing a house or apartment, was to open a catalog or go to a store. The first thing you have to deal with is a large assortment, and these are far from just different manufacturers. It's okay, all types of devices lend themselves well to classification, and we have done it for you. In our articles you will find information about all types of spray guns - from manual to powerful electric. The publications do not contain advertising, we do a balanced analysis, consult with professionals, and try a lot ourselves.This heading will tell you not only about the principles of work, but also give valuable advice on how to optimize the use of a particular unit.... For example, you will find out why a hand-held spray gun consumes more material, and an electric one is so expensive, how to choose a device for your needs and not overpay for unnecessary functions, and what else it may come in handy in the future. Image - DIY spray gun repair

Manual spray gun

Our authors will discuss the types of spray guns not only by the type of drive, but also by other criteria, detailed photographs will make it easy to disassemble the device of such finishing devices, and videos will make it possible to evaluate the convenience of their use and adjust the work with their own hands.

We will list everything that a spray gun can do, as well as how to master these functions, because not everyone is ready to cope with a powerful directed stream of intensively sprayed paint the first time. Are you already uncomfortable with the amount of information you have to master? Do not rush to panic, our articles are written easily, read in one breath and are devoid of meaningless digressions, so you will spend time very efficiently, and skills will not keep you waiting. Each type of work is described by our authors in a separate article, a convenient search will allow you to quickly open the desired publication and start mastering the basics. We describe in the same detail both the painting of large areas and the restoration of small items, and all the tricks of the repair lie on the surface.

The more complex the unit, the more complex its structure - an obvious thing. That is why I don’t want to spend a lot of money on a paint gun of a sophisticated design, although it can do more than a team of painters. But do not rush to draw conclusions. Since you have undertaken to make repairs yourself, then mastering the device and fixing an electric spray gun with your own hands, and even more so a mechanical one, is a task within your powers. True, you need a reliable advisor ... And we offer you a large series of articles not only about the use of such equipment, but also about its repair. It was not for nothing that our authors meticulously collected information on grains, leafing through numerous forums and instructions for a huge amount of painting equipment. Now there are repair manuals for all typical designs, everyone can handle a spray gun breakdown with their own hands. Image - DIY spray gun repair

As you can see, the new technique is designed to facilitate and speed up the finishing process, especially for those craftsmen who dared to start a large-scale project and act with their own hands. Check out our heading and all fears will disappear, you will feel at ease holding a spray gun in your hands. You will know its device, the technique of use, too, this will help to avoid annoying breakdowns, and if such happen over time, then you will not need the help of a paid service. We have collected all the information you need to calmly and efficiently paint any number of square meters.

(17.05.13) Inessa
Hello! There is no paint supply to the spray gun. What to do?

Hello Inessa. The reasons for the absence of a paint composition in the spray gun can be associated with both the device itself and the material used. In addition, improper gun operation can affect this process.

Each individual brand of device has its own instructions for setting the correct paintwork, in particular, the supplied air pressure and paint composition. The instructions supplied with the device itself must be followed closely. In the process, the user begins to "feel" the device and adjust it, relying only on trial and error. Here are the most common reasons for the lack of release of the dye material:

Clogged nozzle
The presence of large inclusions in the paint composition
Mesh damage
Blocking the ink supply channel
Closing the air intake channel
Needle damage
Factory defect in the device

If you operate the spray gun for the first time after purchase and have not properly tested it in the store, there may be a manufacturing defect. Although this is rare. You can replace the spray gun if you have kept the warranty card and receipt.

But, most likely, the reason is not a factory defect, but the user's inexperience. Try adjusting the machine using the adjusting screw. Attach a small piece of Whatman paper to the wall and try to improvise with paint, gradually opening the screw. Regulate the supply of paintwork, not pulling the trigger of the gun. The screw creates barriers to the movement of the needle, preventing it from opening the paint outlet.

If adjusting the pressure supply does not change the situation, you need to check if the needle is dirty. Try to clean the needle and nozzle, repeat the test on a Whatman paper. If the reason is a damaged mesh, it must be replaced.

Sometimes the spray gun refuses to work when the paint outlet is fully open. This may mean that you may be using an overly viscous substance. If large lumps are visible in the mass, grind the paint composition, then strain on a vibrating sieve. Try applying a new consistency to the drawing paper, adjusting the pressure with a screw.

Also check the condition of the air supply. After pouring paint into the reservoir and connecting to the air line, gradually add air pressure. In parallel with the pressure increase, do periodic short bursts of paper on the Whatman paper.

Video (click to play).

Carefully read all storage and maintenance instructions for a particular brand of appliance. Try to rinse all the indicated elements of the apparatus immediately after use. Use materials recommended by your gun manufacturer.