Today everyone has heard about the existence of sandblasting. This is a great way to finish various surfaces. Using this method, you can effectively degrease, clean, remove old coatings, and prepare products for subsequent finishing work. Sandblasting equipment is used even for glass matting. It is not necessary to have a stationary device. If you have a compressor, just buy a sandblast gun and enjoy all the benefits of this processing method.
Scope of application
Let's start with the areas in which this equipment can be applied. The most well-known method is the cleaning of metal surfaces in car body repair. Also, the technology is good for preparing car rims before painting. In stationary devices, high pressure is created, with the help of which a jet of sand knocks off varnish residues, soil, scale and corrosion products from the metal.
Metal, which was processed in this way, after passing the full cycle of work will servelonger due to the fact that this cleaning method is much better than any other. Small grains of sand at high speed crash into the surface being cleaned, beating off rust, which is necessarily found in the pores of the metal or in cracks. Often this cannot be achieved in any other way.
Sandblasting gun may be needed not only by auto repair specialists. It should be in the arsenal of every motorist and home master. In addition to the fact that with the help of such processing it is possible to qualitatively remove old coatings and traces of rust, the surface after sandblasting will be smoother. There are no scratches that occur after cleaning with brushes, sandpaper. This facilitates the application of the base coat of primer and improves adhesion to the metal.
In addition to bodywork, sandblasting is widely used in other areas of activity. With the help of large devices, ships, various elements in factories and industrial enterprises are effectively cleaned. In addition to metal, sandblasting allows you to clean other materials. This is wood, brick, concrete.
You can get interesting effects and ornaments on wood and glass. Using sandblasting, glass is matted, which will then be used as a decorative element.
Device
Sandblasting gun consists of several basic elements. This is the body and handle. There is also a nozzle. A fitting is provided for connecting compressed air, and in some models there is also a valve for adjusting the pressure.
The control bushing is required to ensure that the abrasives flow rate is adjusted. Union nuts or pins that secure the internal nozzle to the body of the instrument reduce the risk of leakage of the working mixture. There is also a threaded sleeve, which is needed to attach the container with abrasive.
In addition to the outer one, there is also an inner nozzle for a sandblasting gun. It has an injection profile and a truncated cone shape. The diameter of the latter narrows as the airflow goes.
General principle of action
Compressor sandblasting gun is used for surface pretreatment. Today, this equipment is mass-produced - it can be easily purchased in stores. But the choice must be approached as responsibly as possible. Budget devices cannot boast of quality, and professional ones are too expensive.
The sandblast gun works as follows. The device is based on a nozzle and a trigger hook. Compressed sand and air are supplied through this nozzle by means of a compressor. The latter is fed through a hose connected to the gun to a special fitting. When the trigger is pressed, air is supplied at high pressure to the nozzle. This is how most models of pneumatic equipment work.
Injection guns
The principle of injection is used here, when pressure drops are artificially created in the compressed air flow supplied from the compressor through the gearbox. Due to this, the speed of the air flow and kinetic energy increase. The air is made heavier by sand orother abrasive materials.
Such sandblasting guns will be more effective than sandblasting chambers. Cameras are bulky, uncomfortable structures. In addition, these tools require special care. The injection gun is more compact. light, and all care is reduced to blowing.
A nozzle is mounted on the body of the device, the size of which is selected in accordance with the pressure that the compressor develops. The choice of nozzle depends on the diameter of the inner injection hole.
Connect a tank or a hose to the handle. Since abrasive dust can enter the lungs of a person, it is recommended to work in a safe manner. Then the compressor is turned on and the air flow pressure is adjusted using the control sleeve.
Ratio of nozzle and capacity and compressor
For nozzles with diameters of six and two millimeters, the compressor must provide a flow rate of 0.2-0.3 m3/min. If the nozzle of the sandblasting gun has a diameter of eight millimeters, and the inner hole has a diameter of three, then the air flow should be 0.6-0.6m3/min. For 10mm holes, 0.6-1.3m3/min. For 12 mm nozzles - 0.9-1.8 m3/min.
A lower flow rate corresponds to a lower air pressure and distance from the end of the nozzle to the surface.
Ejection principle
Another principle can be used. Abrasive material is ejected from the nozzle along it. If availablea sufficiently powerful compressor, characterized by a significant air flow (from 600 to 800 liters per minute), the mixture can be pumped directly through the gun. The ejection sandblast gun for the compressor works according to this principle. But they are not so widespread - it costs a lot to clean one unit of area.
Pistol with tank
Work with such equipment is limited by the capacity of the tank. When the sand runs out, it should be refilled. These devices are perfect for working in relatively small areas. Also, the device will work well if the surface is flat.
Hose gun
These air blast guns are less mobile but can work longer. At the same time, there are no restrictions on the complexity of the processed surface.
There are two hoses connected to the device. One of them serves to supply air from the compressor. The other supplies the abrasive. These are more convenient and compact solutions - there is no bulky tank and it is better suited for processing hard-to-reach places. A sandblast gun with a hose is a great purchase for the garage.
Nozzle and features
To a large extent, the efficiency of using these tools depends on the quality of the nozzles used. This is a very important design element. They are made from ceramic materials or brass. The most important characteristics for this element are the type of hole, its diameter, length, and material.
The diameter of the nozzle is selected depending on the capabilities of the compressor. The performance of the installation depends on how much power the jet has or how much air can pass through the nozzle in one unit of time.
As for the power of the air jet, it is directly proportional to the volume of air passing through the nozzle in one unit of time. To increase power, you need to choose a hole with a larger diameter.
So, if we assume that a nozzle with a hole of six millimeters is 100 percent power, then other nozzles are selected as follows. Eight millimeters - 157 percent, 9.5 - 220, 12.5 millimeters - 400.
The nozzle can be made by hand. But it is better to buy a standard factory product. The sizes offered in stores are from 6 to 12.5 millimeters.
The length is chosen according to how dirty the surface to be cleaned is. For surfaces that are only slightly contaminated, choose short nozzles seven to eight millimeters long. If processing of more complex areas is required, then the length can be significant - up to 230 millimeters. Short nozzles are used when you need to work in hard-to-reach places.
Straight nozzle
Nozzle with a constant diameter along the entire length is able to provide abrasive output at speeds up to 320 kilometers per hour. In this case, the outlet pressure will be about six atmospheres.
Venturi nozzles
These products form a higher speed jet. So the speed canreach up to 720 kilometers per hour. Such products improve the quality of processing. It is important that the use of nozzles with this type of channel does not require the presence of special abrasive materials and does not lead to increased air consumption. Also, the peculiarity of these nozzles is that they cannot be made by hand.
How to choose the right one?
Any type of sandblasting gun will only be effective with the right choice of nozzles. Cast iron and ceramic products are suitable for household tasks. But they are not recommended for large-scale work. So, they are quickly destroyed, which leads to an increase in the consumption of air and abrasive material.
For professional blast guns, more expensive solutions are recommended. They are predominantly made from carborundum, tungsten carbide or boron. They are characterized by high durability as well as versatility in terms of choice of abrasive materials.
What to look for when choosing?
When choosing a sandblasting gun, it is important to consider not only the characteristics of the device, but also the capabilities of the compressor. An important parameter when choosing is the air flow. For normal operation with this kind of tool, the capabilities of the compressor should exceed this indicator of the gun by 20-30 percent.
The pressure of modern models that are on the market today can vary from three to ten atmospheres. If you need to perform work on the decorative design of various surfaces, thenthe choice is recommended to stop on low-power models. For processing concrete, metal and other materials, you need to purchase models designed for high pressure only.
A lot depends on the design of the gun. It has already been noted above that there are pistols with a tank and models with a hose. The former are needed for processing small surfaces. The latter can handle fairly large areas, as well as hard-to-reach places.
Model Overview
There are several models on the market. All of them have different characteristics and features. Compiled a small rating on reviews of sandblasting guns.
Abac 756062
This is the perfect tool. It is equipped with a reservoir that allows the pistol to be more mobile.
The handle is quite comfortable and does not slip in the hand. Combined connections based on rapid and bayonet make the work much easier. The hook allows you to hang the device.
Shneider SSP-Strahiflix
This device is one of the best for decorative processing. It is also equipped with an abrasive tank. This is German quality, although the model is not professional, but rather household. The cost of this solution is very affordable and is about three thousand rubles.
SuperMistral ASTUROMEC SuperMistral 50300
This sandblast gun with dust collector is suitable for professionals. It will be irreplaceable in automobile workshops and on small productions. The set includes severalnozzles.
So we found out what a professional sandblast gun is, how it works and how to choose the right one.
