How does a sandblaster work

When that canister is connected to a gun via a specialized hose, the trigger can be pulled and the sand and air will come out of the canister together. You will not experience hardly any maintenance needs when opting for this style of sandblaster, but the cost of operation tends to be higher.

Also, you cannot refill the canister once it has been exhausted, meaning there is more waste created with this method. For the last option, suction is going to be the main source of the action within the siphon sandblaster.

In this case, a gun is connected via two hoses to both an air compressor and a sand reservoir of some kind. More expensive models are equipped with an automation and control system. Automation increases safety: when the worker releases the gun, a shutdown occurs. The control system not only turns on and off the compressed air supply, but also allows you to go to idle. Hoses must withstand pressure, have minimum internal resistance.

Their diameter and length affect the overall performance. The operation of a sandblaster is related to its type. Nevertheless, sandblasters share pretty much some common principles. They use the finely ground silica sand to scrub and clean rust, paint and other material from surfaces.

These are mainly made of metal. The sandblasters to get to the end of the stain are equipped with a gun designed in ceramic with an interior coating which minimizes the risk of liquefaction of the sand. This gun is compressed air, which allows it to shoot the sand on the surface to be abraded with high speed. The distinguishing principle of the different types of sandblasters is the process by which the sand is introduced into the gun.

The sandblasting gun is equipped with a small tank that must be connected to an air compressor, for this reason it is very often called a compressor sandblaster gun. A special material is placed inside the tank, sold in building material resales, and consists of silica sand or synthetic abrasive sand , both dry, previously filtered and with a defined but variable grain size, so as to be able to choose the most suitable one for the job to be performed.

In this way, the pressurized air, passing quickly into the gun, sucks the sand which, impacting on the material to be treated, is able to remove paints , rust and oxides. Remember to set the compressor at a pressure of at least 8 bar in order to always work at full capacity; furthermore, to obtain optimal results, it is important to keep the jet of air and sand never perpendicular to the material to be processed but always in angled positions.

Finally, as it lends itself well to any surface, as long as it does not contain plastic elements, one must keep in mind not to insist too much on the same area, especially when dealing with delicate materials such as aluminum, in order not to risk removing the structural material. There are basically three types of sandblasters.

These are: the gravity-fed sandblaster, the pressure sandblaster and the siphon sandblaster. This type of sandblaster is gravity fed. The gravity-fed sandblaster is made up of three important parts:.

The principle of operation of the gravity fed blaster is the following: the hopper which is filled with silica sand and the air pipe is connected to the tank. Two reactions occur when the gun trigger is pulled. The gravity-fed sandblaster has three main components.

These comprise a hand-held pressure gun with air hose, a hopper and a pressurized air tank. The hopper sits on top of the pressure gun and holds silica sand. Simultaneously, the area at the top of the gun that connects to the hopper opens up.

The air combines with gravitational force unlike pressure washing to pull the sand down, through the tool and out the barrel. However, they also cost more. This tool applies a concept similar to that of an aerosol can. A special hose connects to a port that is located at the top of the canister and attaches the container to the sandblasting gun.

Automation can more precisely control gun standoff and travel speed back and forth across the part surfaces. This can result in more consistent cleaning and surface preparation with few or no missed spots requiring touch-ups. The additional cost of automation can be offset by reduced labor cost, higher throughput, few rejects and rework, and increased quality. Fixed Station and Robotic Blasters — In fixed station and robotic blasting systems, the blast gun or guns are mounted onto the end of a robot arm.

The parts are loaded manually or automatically into the blast machine and then the robotic gun nozzle scans and blasts the areas requiring surface treatment.

Robotic blasters are commonly found in aerospace and automotive industries for abrasive blasting and shot peening delicate and complex components such as turbine blades, pump impellers, engine parts, and valve components.

Batch and Pass-through Blast Chambers — Batch production systems include tumble blasters and table blasters. In these systems, batches of parts are placed in the blast machine and processed. In pass-through blast systems, parts are pushed through an opening with special brush or rubber flap seals to prevent abrasive leaks.

Inline and Continuous Blasting Systems — In very high-volume and continuous production applications, blasting machines can be integrated into production lines or placed in-line. Alloy strip, plate, or sheet in a primary or secondary metal mill can be continuously blasted. Inline and continuous blasting system is used for descaling and cleaning steel metal stock sheet, strip, plate , structural steel I-beams, channels, angle , pipe and rod skew rolls.

Large in-line abrasive blasting systems are available for production lines where parts or materials are passed in front of abrasive blasting guns or blast wheels. Production blasting systems have automatic guns or remotely operated blasting guns. For sandblasting steel or metal sheet or other continuous or semicontinuous stock materials, blasting nozzles or blast wheels are mounted above and below the stock material.

The abrasive blasting system continuously cleans the steel or stainless sheet as rollers move it along the mill production line. The EPS blasted sheet and strip has a more uniform surface profile, better coating adhesion, and improved weldability. Blast Rooms — Blast rooms can clean part parts too large for blast cabinets, table blasters and hanger blasters. Blast rooms are large enough to accommodate an operator and sometimes even vehicles or material handlers.

Used blast media drops through the grating on the blast room floor. The used media is mechanically or pneumatically conveyed to the reclaimer or separator. Blast operators don a complete sandblasting suit including a blast sandblasting hood, sandblasting gloves, respirators or air supply, and hearing protection. The surface blasting is accomplished with a portable blasting pot or blasting machine integrated into the blast room.

The operator is enclosed in a protected enclosure with windows. The operator can manipulate the gun and move the entire booth vertically and horizontally across the blast room.

Blast booth lifts are useful for impact cleaning tall tanks, structures, ships, and vehicles. Media Separators and Dust Collectors — Most production blast rooms and blasting systems have media separators to allow recovery or reclamation of used blast media. Recovered media and returned to the blast media pot or bin. Dust and disintegrated media are sent to a dust collector and filtration system, which removes the dust for disposal. Tumble Blasters - Tumble blasters have a tumbling basket or continuous rubber tumble belt to tumble parts while being blasted.

The part must be suited for the tumbling action. Certain parts with thin fins, protrusions, or complex geometries can be damaged during tumbling or get jammed together. A hanger blaster or wire mesh belt blaster for those parts.

The basket should be fully loaded to protect the belt or basket from excessive wear. Overloading the tumble belt or tumble basket is not advised because the surface or part might not see the blasting media.

Overload can also damage the tumble belts or baskets. Table Blasters — Table blast systems are used with blast clean heavy castings and forgings. The parts are mounted on a rotary table inside a blast chamber. The chamber doors are closed and the part blasted while the table rotates inside the chamber. The bottom of the part sitting on the table is not exposed to blast media.

The part has to be flipped over to clean the underside of the part. Hanger Blast Systems — In hanger blast systems, parts hang down from hooks. Virtually all of the part is exposed to the blast stream or multiple blast streams, so almost every surface can be cleaned.

Wire Mesh Belt Blasters — Wire mesh belts have a wear-resistant manganese steel mesh belt to convey parts past a stream of flowing blast media. The belt should not be blasted without parts. If only a few parts need a surface treatment, then the belt should be loaded with dummy parts or scrap to reduce belt wear. Monorail Blast System — Monorail blast equipment has an overhead rail.

Parts hanging from the monorail enter the blast machine through doors or a pass-through opening. The parts are blasted and then they exit the other end of the machine where the cleaned parts are removed from the monorail. Roller Conveyor Blast System — Roller conveyors allow heavier metal stock such as billets, thick plates, and structural members I-beams to be blast cleaned. Portable Blasters and Blast Pots — Mobile and portable sandblasting equipment are used in sandblasting large surfaces in the field such as the side of a ship, storage tank, truck, railroad car, bridges, buildings, and farm equipment.

Smaller portable sandblasters consist of portable blast pots, air hoses, blast hoses, blast guns, and air compressors. Portable sandblasters can be carried to the site. Walk-Behind and Vertical Blasters — Walk-behind blasters have a blast wheel to clean concrete floors and an integral vacuum to collect spent media and dust.

Vertical blasters are designed for cleaning concrete and brick walls in industrial buildings. Blasting Trailers and Blasting Trucks - Large mobile sandblasting trailers are towed to worksites. Even larger sandblasting trucks are driven to the remote field sites requiring blasting work. Mobile blasting machines often have engine-driven compressors to provide a compressed air supply.

Internal and Pipeline Blasters — Specialized tools or blasting lance are available for blast cleaning and rust removal on the internal surface of pipes. The tools have collars to center the blast nozzle.

The tungsten carbide deflecting tip directs the blast against the inner wall of the pipe. Spin blast units have rotating heads with several nozzles directed at an angle to the pipe surface. Sandblasting equipment is constructed from a wide variety of parts cabinets, pressure vessels, hoses, guns, nozzles. These individual components are made using sheet metal fabrication, casting, welding, mechanical fastening, machining, and specialized processes.

Blast cabinets and blast rooms essentially start as fabricated metal boxes. They are typically made by cutting, bending, and forming steel sheets, plates, and structural steel into sides, legs, and doors needed to form a box.

With the addition of blast guns, windows, glove ports, doors, turntables, grating or screen, gun or part holders, pneumatic valves, foot pedals, lights, hoses, and reclamation devices, the box is transformed into a powerful tool of industry: a blast cabinet or blast room. Blast cabinets parts can be welded or fastened together.

Fastening allows the parts to be more easily removed for cleaning, repair, and replacement. Welded blast cabinets tend to be more airtight with less leakage of blast media and dust into the shop, but replacement of worn cabinet sides or bottoms is difficult. The abrasive blast stream wears the bottom and sides of the cabinet over time. The seals and windows on the cabinet will also age, wear and require replacement. Blast cabinets and blast rooms for dry or air blasting are made of steel with powder coatings, zinc galvanization, or industrial paint.

Wet blasting cabinets are made of more corrosion-resistant materials such as stainless steel. In certain dry blasting applications such as surgical instruments and medical implants, stainless steel construction materials might be used to avoid iron contamination of a surface.

A system for blasting stainless steel parts would typically use stainless steel shot or grit or nonmetal abrasive media as well. Steel parts or steel shot impacting stainless steel parts can transfer metal to the stainless surface, which can alter passivation and lead to rust on the surface.

Wear-resistant steel liners or wear plates are strategically placed within blast chambers to reduce wear of the blast machine. Wear-resistant alloys include manganese steels such as Manganal and nickel and chromium white cast irons such as Ni-Hard alloys.

Sandblasting equipment tends to be self-destructive due to the aggressive blast media. Blaster parts are consumable and will wear out over time as abrasive or media flow over or through these parts. Of course, the blast media or abrasive grits are consumable as well. Some types of blast media like steel shot, ceramics, and aluminum oxide can be recycled through the blaster a hundred times or more.

Soda, dry ice, sand, and coal slag are only used once. The parts in abrasive blasters, wheel blasters, and shot peeners need to be regularly inspected for wear.

When the nozzle's inner diameter changes or the throwing blades change geometry, the efficiency of the blasting process can be compromised. Boron carbide, alumina, pure WC, and silicon carbide ceramics are amongst the most wear-resistant materials.

Depending on the blast media, cemented tungsten carbide and SiAlON nozzles will last 10 to 20 times longer than ceramic or alumina nozzles. Boron carbide is the hardness and the most wear-resistant of the nozzle materials. Boron carbide typically costs 3 times as much as cemented WC, but boron carbide lasts 3 to 25 times longer than cemented WC or sialon. They do not have the toughness and impact resistance of cemented tungsten carbide. Binderless tungsten carbide WC nozzles have double the life boron carbide nozzles.

Steel nozzles are acceptable for air blow guns, washout guns, and blasting of exceptionally soft media such as soda, dry ice, walnut shells, and plastic media. Steel nozzles will not break when dropped. Economy and non-industrial sandblasters for home or DIY use often come with low-cost steel nozzles.

Based solely on wear resistance boron carbide and binderless WC last up to seven-time longer than cemented WC. If you bang a boron carbide or silicon nitride nozzle into a part, grate, or cabinet wall, then the nozzle is more likely to crack compared to a cement tungsten carbide nozzle. Nozzle service life will depend on the media blasted through the nozzle as well. Sharper angular steel grit will wear nozzles faster than spherical cast shot.

Aluminum oxide and silicon carbide will wear out nozzles more quickly compared to garnet or coal slag. Cleaning equipment blasting plastic media, soda, corn cobs, or walnut shell media could last indefinitely.

In addition to consumables and wear components, a variety of sandblasting accessories and ancillary equipment can improve the blasting process:. Sandblasting and shot peening processes also require abrasive blasting personal protective equipment PPE for operators:. Sandblasting equipment modifies surfaces of parts or structures in a variety of ways depending on the media type and blasting parameters. Softer media at lower pressure can gently remove coatings. Extremely hard abrasives projected at high pressures can aggressively etch and pattern or carve surfaces.

For example:. Some of the end-use or surface modification functions sandblaster can provide to optimize your production operations are:. Abrasive blasting is highly effective at cleaning surfaces and stripping or removal of rust, oxide scale, mineral deposits, corrosion grease, dirt, coatings, sealants, carbon deposits, and varnish.