Which compressor to choose for car painting

Choosing a compressor for car painting

Painting a car is a responsible undertaking. The main task of the master is to choose the right compressor for applying the paint layer. The quality, strength and consistency of the coating depend on this unit. If the choice of compressor for painting a car is made incorrectly, then pressure fluctuations and poor quality of painting are possible.

Compressor classes

There are professional, household and semi-professional models:

Household ones are intended for periodic use with a working pressure of up to 8 bar and a continuous operation time of up to 20 min/hour. The volume of the receiver in such devices varies in the range of 6-100 liters.
Semi-professional (semi-domestic). Operating time – no more than 40 min/hour, pressure – up to 16 bar. Supplied with a receiver with a volume of 50-100 l.
Professional (industrial) compressors are used in production. They are characterized by a large resource and high productivity. Receiver volume – 25-900 l. Suitable for long-term intensive work.

In addition, compressors are divided into mobile and stationary:

Stationary ones are installed on a special platform;
Mobile ones are equipped with wheels and a special handle for transportation.

Application

Which compressor to choose for painting a car so that it fully complies with the parameters required for the job? After all, it will allow you to perform not only high-quality final painting of the car, but also a number of other tasks or related procedures:

Launching equipment that operates using compressed air;
Applying primer, varnish or paint;
Blowing/purging of parts;
Tire inflation;
Removing any kind of contamination from mechanical components;
Application of anti-corrosion agents in hidden and hard-to-reach car cavities;
Working with pneumatic impact wrenches, polishing or grinding pneumatic tools;
Other.

Characteristics

Belt driven compressor

Choosing a compressor for car painting will be simplified if you pay attention to the following technical characteristics:

Weight and dimensions;
Receiver volume (l);
Productivity (l/min);
Compressed air pressure in the receiver (Atm);
Engine: petrol or electric
Power supply (220 V, 380 V or mixed - 220/380 V);
Power consumption (kW) of the primary power plant.

Performance

Before choosing a compressor for car painting, you should first consider one of the most important factors - performance. It is measured by the amount of air compressed per minute (in liters). Please note that when working with different spray guns, different volumes of air will be consumed.

Pressure

In receivers, the maximum discharge pressure is approximately the same - 8-12 atmospheres. As soon as the air is compressed to 8 atmospheres, the compressor unit will automatically turn off. The threshold for turning on the unit is 6 atm.

When this indicator is reached, the missing gas is replenished. You can set the desired value yourself; it will be controlled using a pressure gauge.

A thermal relay will be very useful - the option of automatic shutdown in case of overload.

Power supply

It is worth remembering that when the pressure increases by 1.0 bar, the compressor will consume 8% more electricity.

After all, while the compressed air reaches the consumer point, a significant pressure drop occurs, both in the filters and in the dryer and pipelines.

An accurate determination of the required power and, accordingly, the correct choice of compressor will help reduce energy costs.

Volume

To paint a car, it is better to choose a receiver with a volume of at least 50 liters. Often, an increased volume of the receiver allows you to compensate for the insufficient performance of the device.

Kinds

In addition to the above, there are several types of compressors for car painting, which are classified according to various criteria, for example:

According to the lubrication system (oil-free and oil);
By type of drive (belt, coaxial);
By the number of compression stages (one-, two- or multi-stage);
By the nature of air compression (membrane, piston).

Oil-free

One of the most popular are oil-free piston compressors. They are used for work where the oil content in the paint is not allowed to exceed 0.01 mg/m3. The units allow you to carry out high-quality painting and achieve the ideal appearance of the painted surface.

To remove excess moisture from the compressed air stream, an adsorption dryer is used, which is characterized by a dew point of no more than -70⁰С. The compressors are very reliable and easy to operate, and do not require professional maintenance.

But the list of their functions and service life is limited.

Oily

Piston coaxial compressor Fubag with direct drive

More interesting would be an oil unit that uses a lubricant spray system. It is presented in several versions. A common distinctive feature of such devices is the oil that is poured into the piston pump crankcase.

Due to it, during operation, a film is formed that prevents direct contact of metal with metal. Consequently, wear of parts and heat generation are reduced, but high compressor performance is maintained. Since some of the lubricant can enter the compressed air, various filters and oil separators are used.

The main disadvantage is that in frosty weather this device starts worse than an oil-free one, since the oil thickens in the cold.

Oil compressors for car painting are equipped with a belt or direct drive type.

Direct drive (coaxial)

In this case, the shaft of the electric motor and the crank are combined through a coupling, forming a single unit. Their main advantage is compactness and simplicity of design, but such a design makes heat removal difficult.

Belt driven

They operate using a standard belt drive system from a pulley and an electric motor. They are distinguished by reliable air cooling, high performance, reduced noise levels and a long service life due to the reduced engine speed. Belt-driven compressors, in turn, are divided into one-, two- and multi-stage.

Piston

These are the most popular models due to their simplicity and reliability. The principle of their operation is that the electric motor activates the piston through the crankshaft and connecting rod.

Under pressure, the exhaust and suction valves close or open. This type of compressor for car painting can be equipped with one or several cylinders arranged in a V- or W-shape.

To increase productivity, such units use two-stage compression technology.

Screw

Air compression in these models is carried out due to the simultaneous rotation of rotors, which are located parallel to each other in the housing. In this case, special cells are formed, the volume of which gradually decreases, creating increased pressure.

The devices are equipped with monitoring, control and protection systems (ACS), which allows you to quickly and easily configure them to operate in the desired mode, depending on the conditions. This will ensure an uninterrupted supply of compressed air over a long period of time.

They are characterized by low energy consumption, minimal vibration and noise levels, high quality of exhaust air, durability and reliability. They are used in large enterprises where continuous operation is required.

Membrane

They are classified as household tools and are intended for occasional use. A distinctive feature is low performance coupled with high pressure.

Have you made your choice?

The modern market offers a wide selection of compressors, both foreign and

Application of paint and varnish coating

domestic producers. But when deciding which compressor to choose for painting a car, it is important to remember that you should not save on it. A unit with good characteristics will pay for itself very quickly (perhaps after the first painting of the car or its individual elements). Indeed, often, even the cost of painting a bumper is comparable to the price of a medium-power compressor.

We invite you to watch a video that will help you make the final choice of compressor for car painting:

Source: http://KrasimTachky.ru/materialy-i-oborudovanie/kak-vybrat-kompressor-dlya-pokraski-avto.html

Compressor for painting a car: which one to choose?

Painting a car is a responsible undertaking. Regardless of the area and configuration of the body, which is subject to independent application of the paint layer, choosing a compressor for painting a car is the main task of the master. The quality, consistency and strength of the applied layer depends on the compressor.

Types of compressors for car painting, price

There are the following types of devices that apply pressure to the spray unit:

A piston receiver oil device with one cylinder, a capacity of 25 liters, which gains 130 liters in 60 seconds under a pressure of 8 atmospheres, is an excellent option for learning to paint or applying a local paint layer to individual parts of the body (its cost rarely exceeds $100).
Two-cylinder oil unit of receiver type with a capacity of 50 liters, gaining 330 lmin under a pressure of 8 atmospheres. Also a similar device with one cylinder, pumping pressure with an indicator of 10 atmospheres (200-300 cu – its real price). These units are suitable for C grade work or overlapping painting.
Receiver oil devices with a capacity of 200 liters with a speed of 515 lmin, operating on pistons (their cost is around $ 1,200). This compressor is suitable for professional painting of both cars and trucks.

Depending on the specifics of the work, the planned period of use and the desired quality, it is recommended to choose a compressor for painting a car, the price of which will correspond exactly to your needs.

Types of designs of pumping units for painting

There are several compressor designs that are used for painting different surfaces:

Piston devices are considered the simplest and most reliable, but they are not ready for high performance (this type of pumping units is rarely used, like a compressor for painting a car, only in the case of masking peeling paint).
Screw-type devices are used to apply a paint layer to car bodies. Their operation is more economical than piston ones, and installation and operation are simpler.
Turbine compressed air machines are great for painting jobs. The performance of this compressor for painting a car is high, but it is not suitable for mobility and control.
Oil-free and other designs that pump clean air are not suitable for pneumatic supply of paint to a car body due to the high hydrogen content in the stream. This may cause bubbles to appear on the surface.
Combined oil-piston designs are the best for painting cars: the paint is supplied evenly, these compressors are easy to operate and last a long time.

Performance of compressors for car painting

If you are faced with choosing which compressor you need to paint a car, we recommend relying on power and performance .

Units with a pressure of up to 8 atmospheres are used to apply paint to individual areas of the body - from 5 sq. cm, to painting one side (hood, door, roof or side part).

If the performance indicators are in the range of 250 - 330 lmin, then the blower can be used in large-scale work (but not in an entire cycle).

With power parameters above 330 lmin, the device is recommended to be used to apply a layer in a full cycle at a time to the entire body.

Which compressor to choose for car painting

Watch the video on how to choose the right compressor for painting a car.

The answer to the question “How to choose a compressor for painting a car?” It will be that the device must be universal in any conditions. Outdoors, indoors, in summer and winter, in rain and drought, the unit must function fully.

be recharged from any source: from the cigarette lighter to the transformer box. It is necessary that its application be as wide as possible - from inflating bicycle tires to painting a refrigerator van in one pass.

Output pressure and performance are the leading indicators by which you need to navigate when choosing a compressor. The optimal parameters will be 10 atmospheres and 250 lmin.

Units operating without oil are more resistant to low temperatures than their oil counterparts. But their wear is higher than that of oil piston devices due to high friction in the piston block.

When choosing a compressor for painting a car, do not be guided by price - the cost of devices operating with and without oil is approximately the same.

But in terms of quality of work, “dry” compressors lag significantly behind their “lubricated” counterparts.

Which compressor to buy for car painting

belt-driven units . They come with one and two feed stages.

For work in close proximity to residential premises, devices with two-stage feed are most suitable - they are the most productive and produce virtually no noise during operation.

The best option would be an electric screw unit. It is ready for uneven loads, has high pressure and performance, is economical and easy to operate.

The tandem piston two-stage compressor ranks second in popularity among professionals.

DIY compressor for painting a car

If you don’t have a compressor for painting it, but you really want to paint it, then we can offer two options:

Progress:

It is necessary to cut a hole in the car inner tube into which a nipple nipple is glued to connect a manual or electric pump.
A nipple for feeding into the spray gun (without nipple) is also mounted.
Air flows from the pump into the chamber, the flow of which can be adjusted by arbitrarily pressing it.
From the chamber, air under pressure enters the spray gun and provokes a stable release of a jet of paint.

To do this, you will need an old refrigerator compressor and an iron tank that can withstand the air pressure you need.

The video shows how to make a compressor for painting a car with your own hands:

Source: https://za-rulem.org/tuning/elektronika/kompressor-dlya-pokraski-avto.html

How to choose a piston air compressor for your garage

Having finally decided to buy a compressor for your garage, you will of course be faced with the question: how to choose exactly the compressor that would meet all the parameters necessary for your work. Using the knowledge gained in this article, you will be able to make a fairly accurate choice.

What is a compressor for?

By using a compressor in combination with special interchangeable tools that require compressed air to operate, you can expand your capabilities as a repairman as much as your wallet will allow. Here are just a few points about using an air piston compressor:

Applying paints, varnishes and primers using a spray gun (car painting).
Blowing, wherever you need to blow well.
Application of anti-corrosion compounds even into hard-to-reach hidden cavities of the car.
Working with polishing and grinding pneumatic tools.
Working with a wrench.

Probably, if you think about it, there are many ways to use the compressor in the garage besides painting.
So, we have already realized that we cannot do our work without this device. Moreover, many car repairmen jokingly call this unit the “breadwinner”. All that remains is to choose a compressor for painting according to our needs, and of course according to our wallet.

What types of compressors are there?

Now let's look at the types of compressors for garage repair and car painting, and how they differ from each other.
The most popular compressors for painting are piston type air compressors .

They are divided into two types: oil and oil-free . Such compressors are extremely simple, reliable in operation and do not require professional maintenance.

Oil-free piston compressors are usually used for the simplest needs - pumping up tires, blowing out a jet, and finally painting the gate in the garage. Therefore, we will not consider them as a great assistant in car repair and painting. I will only note that oil-free compressors are the cheapest in terms of cost.

Now, let's take a closer look at what piston oil compressors are, what their characteristics are, as well as their differences.
They have one thing in common - oil is poured into the compressor piston drive crankcase.

Also, compressors are available with direct drive and belt drive.

Belt-driven compressors are also divided into two types: single-stage and two-stage.
Two-stage ones make less noise during operation and are more productive. Belt-driven compressors are considered more reliable, which is determined by the features of its design. A belt drive is installed from the engine to the flywheel of the compressor head.

Here are some positive differences between a belt-driven compressor and a direct-drive compressor:

The electric motor rotates at a lower frequency.
The diameter of the flywheel is greater than the diameter of the engine pulley.
Reliable air cooling system.

Design and characteristics of a piston oil compressor

Important characteristics to consider when selecting and purchasing an oil compressor:

Power supply (220-230 V, 380 V, mixed - 220/380 V)
Power consumption (kW)
Productivity (amount of air produced - liters per minute)
Maximum discharge pressure into the receiver (atm)
Receiver volume (liters)

Now let's look at each one separately.

Power supply

Well, here, in principle, everything is clear, if you have three-phase power in your garage, then the choice is obvious, if only 220 volts, then no questions arise either.
I recommend monitoring the voltage in your garage using an AC voltmeter.

Data should be taken for the morning, afternoon and evening. If the voltage is even and does not drop below 200 Volts, then everything is OK. If the readings jump from 230 to 160 Volts, then stable operation from the compressor cannot be obtained and in this case you should take care of purchasing a voltage stabilizer.

Power consumption

When choosing, you should again rely on the quality of the electrical network where you will use the compressor. If the electrical network is old, the wires are thin and they consist of twists, then the high power consumption can cause a fairly serious voltage drop and high current, resulting in overheating of the wires and the possibility of a fire.

When purchasing a high-power compressor, first make sure that the wires running from your garage to the distribution panel are not twisted and have a sufficient cross-section. If it is not possible to do this work yourself or you are not qualified enough, then seek help from a qualified electrician.

Performance

One of the most important indicators in the characteristics of the purchased compressor. It is measured by the amount of compressed air produced, liters per minute.

If you are going to paint cars, then you should take into account that when working with various spray guns, air consumption is required, sometimes quite significant.

And different spray gun systems have their own requirements for the amount of compressed air consumed.

For example, spray guns of the HVLP (low excess pressure - high air flow) consume from 170 to 550 l/min, depending on the design. Read more about choosing a painting system and a spray gun for a compressor here.

IMPORTANT! When purchasing a compressor, be sure to compare its capabilities with the air consumption requirements of the spray gun you are going to use.

If these requirements are ignored, the compressor will constantly thresh without breathing, the outlet pressure will float, and the unit will overheat, which is not good. Well, the quality of painting will be appropriate. To protect against overheating, all compressors are equipped with a thermal relay that will turn off the unit if overloaded.

Maximum discharge pressure into the receiver

Measured in atmospheres (atm), this indicator is approximately the same for all compressors of this type and amounts to 8-12 atm. The output pressure regulator sets the desired value, which can be monitored on the pressure gauge.

Receiver volume

It is measured in liters; for garage and painting work, I do not recommend taking less than 50 liters. Partially insufficient performance can be compensated by increasing the volume of the receiver.

Based on the above characteristics and the contents of your wallet, you can begin to select and purchase the much-needed unit.

We have already got an approximate picture, let's draw a balance.

So, for normal operation with various spray guns, we need a belt-drive compressor with a power of approximately 2 kW, a capacity of at least 240-260 l/min, and an outlet pressure of 8 atm.

and a receiver volume of at least 50 liters.

Here I have given the minimum acceptable values for normal work in a garage; if, with your choice, they differ more, that’s only better.

Some tips for operating a piston oil compressor

If during your work the compressor does not operate in a short-term-repeated mode (turns on and off), but threshes constantly, this means that the air consumption exceeds its production by the compressor. Consequently, wear of the cylinder-piston group increases, and the unit overheats. To protect against overheating, the compressor has a thermal relay that will turn off the device if overloaded. If the thermostat is constantly tripping, then this is a signal that something is wrong and can lead to compressor failure. If the thermal relay protection has tripped, you must wait until the compressor has cooled down, and then start the compressor again.
At temperatures less than +5 degrees, there may be problems with starting the compressor motor. At low temperatures, the oil thickens and it is difficult for the engine to turn the piston group. If you need to operate the compressor at low temperatures, I recommend forcibly warming up the oil sump, for example with a heater, lamp or hairdryer before starting it.
Drain the water from the receiver regularly. Before painting - definitely!
During continuous operation, clean or change the air filter located at the inlet at least once a month.
Check the oil level in the compressor crankcase regularly.
At least once every six months, thoroughly clean the compressor to remove any remaining paint, dust and other deposits, which will increase the efficiency of the cooling system and, accordingly, extend its service life.
At the end of the work, do not forget to unscrew the outlet pressure regulator to zero. Otherwise, after some time it may become coked and stop performing its function. Also, this may cause failure of the pressure gauge indicating the outlet pressure.

I specifically did not focus your attention on manufacturers in this article, since this is a matter of taste and some personal preferences.
If you have questions, ask in the comments below, I will try to answer. And please don't ask me for advice on specific compressor models, I don't sell them and I don't keep track of models. I gave you a fishing rod, and you can catch the fish yourself.

Source: https://sam-avtomaster.com/oborudovanie/kak-vybrat-kompressor

Features of air compressors for car painting: types of compressors, operation and selection rules

Purchasing a compressor is a very important process, because purchasing a high-quality device will allow you to independently service the car without the need to use the services of various workshops, which are very expensive today.

The main problem with choosing an air compressor for painting is that this device is available in huge quantities in modern markets.

If you approach this issue thoroughly, taking into account the necessary technical characteristics, you can find a model that will provide high-quality car painting and will not put a big dent in the buyer’s pocket.

This device can be called a universal unit, the main task of which is to deliver gas and air under pressure to the surface being treated .

When painting is used, a compressed mixture is prepared in it, which subsequently enters the spray gun.

Devices with a small chamber and low pressure are not able to cope with this task efficiently, leading to the appearance of unevenness and smudges.

They can only be used for pumping up wheels. But powerful structures have a very wide range of actions:

applying a coloring composition or primer to the vehicle (provided that a spray gun is used);
purging of pipes of various machine systems, cleaning of mechanical components;
ensuring the operation of car diagnostic devices;
working with screwdrivers, impact wrenches and other construction equipment;
car wash;
spraying anti-corrosion agents, which is especially important when treating hard-to-reach places.

The compressor is also often used as an auxiliary device for grinding and polishing with pneumatic tools.

Common device designs

There are several types of this equipment, each with its own characteristics:

piston;
screw;
oil-free;
turbine;
oil-piston.

As for piston devices, they are reliable and easy to use. However, before choosing a compressor for painting, you should especially carefully read the main criteria of this type of apparatus. Weak devices will not provide high-quality painting and can only be used to slightly mask the peeled coating.

The main advantages of such a mechanism include low cost, easy replacement of failed parts and low electricity consumption. Its operation is based on the conversion of electricity by an electric and diesel drive into a compressed air mixture, which, moving through a tube, drives the compressor.

Screw modifications are most often used when it is necessary to apply a paint layer to the car body. Such devices are very easy to operate and install.

The air in the system is compressed due to the simultaneous rotation of parallel gates in the apparatus body.

This provokes the formation of slowly decreasing compartments, creating strong air pressure.

This type of compressor is equipped with an automatic control protection system, which ensures an uninterrupted supply of gas, allowing, if necessary, to set the required mode even in difficult conditions. Most often, these devices are found in large enterprises, the work of which is associated with the need for uninterrupted and long-term operation.

Oil-free compressors are not used to treat the surface of a car, since during operation they supply a lot of hydrogen, as a result of which bubbles remain in the paint layer applied to the body.

Turbine devices with high performance have proven themselves quite well

However, they have a certain drawback - lack of mobility.

Oil-piston are distinguished by their compact design and excellent quality of work performed . They are ideal for painting.

Selecting the right spray gun

To operate the compressor, you must additionally purchase a spray gun. There are many sprayers on the market, so before buying a specific model, you should decide on the task it will need to perform: masking minor flaws or high-quality painting of an entire car.

There are seven types of spray guns, differing in the mixture spray system. The most popular include the following:

LVLP , which have low pressure and small volume. Their advantage is that there is no need to use powerful compressors, since they do not require high pressure at the inlet and outlet of the spray nozzle. Also, when using them, a minimal amount of material applied to the car body is wasted. The most relevant use of LVLP devices is when it is necessary to remove minor scratches.
HP spray guns have high pressure, are quite convenient and functional to use. But a significant drawback can be called a large volume of paint flying outside the object, that is, excessive consumption of the mixture used. Moreover, as a result of the turbulence formed, dust rises in the air, which subsequently settles on the surface to be painted.
HVLP , equipped with large volume tanks, but having low pressure. They are quite economical in using the color mixture, but require the use of powerful compressors. In addition, the engine requires a large amount of oil to operate, which means it is inevitable to equip the equipment with additional filters.

What to choose

When purchasing this device separately from the spray gun, you need to focus on the meaning of the spray gun. People who do not understand anything about the features of this equipment can purchase a kit right away.

When choosing a compressor, you should initially ask the seller about the performance of the device. This term refers to the amount of air coming out.

For HVLP type spray guns, a device with a capacity of 360-515 liters per minute should be used. In this case, the required pressure is 2.5-3 atmospheres at the inlet to the spray gun nozzle and 0.7 units at the outlet.
HP sprayers can operate on compressors with a capacity of up to three hundred liters. The required pressure on them should be 5 and 1.5 atmospheres at the inlet and outlet, respectively.
The required output for LVLP spray guns is equivalent to 150-350 liters in 60 seconds. In this case, the optimal pressure at the inlet is two atmospheres, and at the outlet 0.7−1.2.

It is worth considering that often the technical information indicated in the device passport may not correspond to reality. The described indicators only indicate theoretical power and performance data, calculated in accordance with the volume of the piston and cylinder. In fact, the power turns out to be half as much as the set values.

What to pay attention to

When understanding what kind of compressor is needed to paint a car, you should initially decide on the goals that should be achieved when performing repairs. Depending on the task, performance indicators, power supply quality and receiver volume are taken into account.

The most important parameter is power consumption. This indicator must correspond to the quality of the electrical network installed at the site. Old wiring with thin wires twisted into it will not support powerful models.

Air compressors, depending on the design features, are capable of producing up to 550 liters of air per minute. The performance indicator must necessarily match the parameters of the spray gun used, otherwise the device will work without stopping. As a result, the equipment will overheat and the quality of the final product will decrease.

The majority of compressors are equipped with an electric motor, which means that they need to be connected to the network. Depending on the specific model, the device can be three or single-phase.

With an available voltage of 220 V, it is necessary to select a unit with parameters corresponding to this indicator. If there are constant voltage drops in the operation of the electrical network, it is better to connect the equipment through a stabilizer.

Regarding the volume of the receiver, models with a capacity of over fifty liters are considered optimal. Sometimes, thanks to this, it is possible to partially compensate for the low performance of the device.

The discharge pressure in almost all compressors is the same and can be adjusted manually.

Features of operation

In order for the equipment to serve for a long time and perform the tasks assigned to it, when using it, the requirements put forward for this process should be taken into account.

Work must be carried out with short pauses. If this advice is not followed, paint consumption may exceed production.
Using the unit at low temperatures requires warming up the oil sump using a lamp or a regular hair dryer.
Frequent use of equipment entails the need to regularly replace filters.
Every 5-6 months the device should be completely cleaned.
When performing the work process, it is necessary to periodically look at the readings of the device from which the compressed air comes. They should not exceed the norm.
It is important to monitor the condition of the oil in the system and fill in new oil as needed.
Do not suddenly change the pressure force in the pneumatic system.
Do not allow the air supply hoses to be twisted or broken.
It is contraindicated to start the equipment if there is a malfunction of safety valves, chips, cracks, or leaks in the connections of the main working elements of the compressor.

By complying with these requirements, you can increase the service life of the unit, as well as achieve good quality of work performed.

Source: https://tokar.guru/stanki-i-oborudovanie/kompressory/kak-vybrat-vozdushnyy-kompressor-dlya-pokraski.html

Which compressor is best for painting a car?

In this article we will talk about one of the most important tools - an air compressor for painting a car . Without it, and without a spray gun for painting a car, it is not possible to carry out painting work. Therefore, it is mandatory to have a compressor in your garage or workshop.

There are a huge number of different types on the market, and how to choose the compressor for car painting that you need is quite difficult. Next, in order not to be mistaken, we will consider the main characteristics that you should pay attention to when choosing a compressor for painting.

Why do you need a compressor and what is it anyway?

In Russian words, a compressor is a device for compressing, storing, and supplying gases (air, steam, refrigerant) under pressure.

In body repair, the main task of an air compressor is to prepare an air mixture (compressed air) for its further use.

When blowing parts, painting, connecting various pneumatic tools (grinding machines, blow gun).

In addition to being used in painting work, you can use it to inflate car tires, blow out dirt from any hidden places in the engine, connect a sandblaster and a lot of other useful actions. The compressor will be a must have for anyone doing body work and will be a useful piece of equipment in the garage for any purpose.

Main characteristics of air compressors

The market offers a large selection of air compressors from different manufacturers at different prices. As with other products, there are products for different purposes and in different price categories.

In a special store they can sell you a small screw compressor with a refrigeration (in the form of a refrigeration unit) air dryer “at an exorbitant price.” This device will decorate any garage.

However, the economic component should be the main criterion before choosing a compressor for the garage.

Regardless of the device and operation, all compressors have five technical parameters:

Productivity - measured in liters per minute. The performance is divided into output and suction performance. The latter is equal to multiplying the volume of the cylinder by the number of strokes per minute. The output performance of the compressor takes into account all the losses associated with the entire operating process, and is always 1 - 1.5 times lower than the suction capacity. For example: the suction capacity of an air compressor is 400 l/min, then the real one will be 300 – 340 l/min.
Working pressure – measured in kg/cm? that is, the atmosphere. And also in bar and psi. 1 bar=0.98 kg/cm. Psi pressure is pressure in pounds per square inch. 1 bar=14.2 psi.
Receiver volume is measured in liters. One of the most important indicators required for painting a car.
Electrical power consumption – measured in kilowatts.
Operating voltage 220v or 380 volts.

Important note! The technical data contained in the instrument passport often differs from the actual data. The numbers show only theoretical performance and power, calculated by volume, cylinder and piston size. And the real power due to losses can be half of these values. It is the real indicators that are associated with the tool you will use.

Air piston compressor device

Air piston compressors for car painting are the most popular in both professional and private activities. The photo below shows the structure of a typical Fubag piston belt compressor.

Main advantages: wide price range, from the most inexpensive to the most powerful expensive ones, simplicity of design and ease of maintenance. With proper and careful use, they will last a long time.

A piston compressor for painting is quite unpretentious and can work in difficult conditions (dusty rooms, cold and heat).

A cylinder with a piston and rings inside for pumping air.
Impeller (blades) for cooling the piston group.
Reducer with pressure gauge and hose connector.
Oil filler neck.
Oil level indicator
Foam filter for suction.
Electronics, capacitors for starting the engine.
Electric motor.
Automation, on/off relay.
Pressure gauge (receiver pressure).
Tank (receiver).
Condensate drain valve.

The operating principle of an air piston compressor is very simple. An electric motor drives a piston located in a cylinder (like a car), which compresses the air, then is supplied through pipes to the receiver. The automation turns off the compressor when the required pressure is reached (8-12 atmospheres).

As the pressure decreases, the automation starts the electric motor and the process repeats. These parameters can be adjusted on the automation unit. The compressor is lubricated by oil, which is poured into the crankcase.

There is also an emergency valve that is triggered when the pressure rises above 12 atmospheres if the automation fails.

Piston belt compressors are available in diesel and gasoline, and also exist without belts (coaxial) in the photo below. For coaxial ones (without a belt), the engine and compressor head are on the same axis. This greatly reduces the cost and reduces the size. Without belt devices, they make a lot of noise, have high speeds, as a result of which they fail faster in relation to belt (axial) ones.

Air screw compressor working principle

Screw compressors for painting are an ideal option. They have high productivity, power and efficiency. Screw ones are designed for long-term operation without interruptions and overheating.

They are practically silent and do not vibrate during operation. Due to their design, screw air compressors are reliable and durable. This is the best choice for painting work, both professional and private.

But this type has one thing. The prices are very high.

Briefly, the principle of operation is that they operate using two screw rotors, a leading and a driven one, the leading rotor is connected to the engine. We won’t go into more detail into the operating principle; it’s not that important; there’s plenty of this information on the Internet.

What kind of compressor is needed for painting in a garage?

From the above, one thing follows: the best compressor for painting a car in a garage or in a small private auto repair shop is a piston belt oil compressor. By choosing this type you get a reliable and simple tool. Which, if handled properly, will last quite a long time.

Before purchasing, you need to decide on the following:

For what purposes is it needed?
How much work will you do?
Will additional equipment (pneumatic tools) be used?

The main parameters that you should pay attention to before choosing a compressor for painting a car.

Performance
Receiver volume
Power consumption.
Voltage 220 V or 380 V

To comfortably use pneumatic tools, you need a compressor that is a little more productive than just for painting.

Theoretically, it is believed that the compressor performance should cover the air consumption by at least one and a half times. Let's do some small calculations. Let's say a paint sprayer consumes 300-400 l/min.

, which means for comfortable use you need a painting compressor with a capacity of 400-600 l/min.

If possible, you should always choose a compressor with a power reserve, with good performance; it works with long breaks (without overvoltage). And with low productivity it works almost constantly, the air heats up more and contains more water and oil vapors than cold air. Therefore, the less moisture and oil in the air, the better the coloring.

An important selection criterion is the volume of the receiver. It determines how much air is available. An important indicator for complete painting of a car, where non-stop work with a spray gun is required. If you wait until the compressor pumps up the required pressure, the paint or varnish will already begin to set. Hence, deposits and other defects are possible. And in general this causes a lot of inconvenience.

The best choice would be an air compressor for painting in a garage with a capacity of 500-600 l/minute and a receiver volume of 300 liters or more.

Such a device will be enough for comfortable full or partial painting of a car. It is also possible to use a pneumatic tool. However, the bulk of those available at a price have a performance lower than the required 150-250 l/min and a receiver of 30-50 liters; these indicators will clearly not be enough for high-quality painting work.

Such a low-performance tool may be suitable in one case if you are going to work with very small volumes. Suitable for painting motorcycles, detailed painting of cars, aqua printing.

Another thing to pay attention to before choosing which compressor is the electrical power. This indicator is especially important for ordinary garage conditions. If the garage has weak electrical wiring, then a powerful compressor above 1-15 kW is not recommended and even dangerous.

Let's summarize all of the above and conclude which good compressor to choose for body painting work.

Piston type, oil with belt drive
Capacity from 500 liters per minute
Tank volume (receiver) from 200 liters or more

This tool will be sufficient for any painting work in a garage or small service station.

What to look for when buying a used compressor

If you don’t have enough money to buy a new one, you can buy a used compressor. There is, of course, a risk of taking a “tired”, worn-out tool (few people will say under what conditions it worked and whether it was serviced correctly). If you don’t know how to choose a used compressor, then you need to pay attention to some things and check it.

When buying a used compressor, first evaluate its appearance. If it is dirty, stained (with oil, paint, etc.), it means it worked in difficult conditions, or it was simply not looked after.

Ask the seller if the rings, pistons, seals have been changed and what kind of repairs have been made. If the piston group was replaced, then the compressor has worked quite a lot, I would not recommend buying one.

How to check a used compressor? Do the following test: Completely bleed the air receiver, start the compressor and note the time. If it pumps for a very long time (before shutting down) and as the pressure in the receiver increases, “the work seems to slow down,” then the compressor requires repair. A clear sign of poor compression in the piston group.

Pay attention to the color and level of the oil in the crankcase; if it is very dark, it needs to be replaced or topped up if the level is low. When buying a used instrument, listen for extraneous noises, knocks, etc., there should not be any.

Source: http://www.myavto.net/instrument_i_oborudovanie_dlya_pokraski_avtomobily/72-kompressor-dlya-pokraski-avtomobilya.html