Sandblasting work: choosing sand for household and household needs
Sandblasting machine is a device for cleaning surfaces from paint, rust, scale and dirt by exposing the surface to a directed spray of abrasive. A sandblaster sprays small granules of a substance under high pressure and speed. Particles of the sprayed material - abrasive - hit the surface so hard that they knock off the surface layer from it. This layer can be dried dirt, rust, scale, or just paint. Previously, only sand was used in sandblasting devices, which is why they were called sandblasting. But in fact, the number of abrasives for sandblasting is much greater. The speed and quality of surface cleaning depends on the material and the size of its granules.
In this article we will look at what types of abrasive there are, which abrasive for sandblasting is better, the characteristics of the types of abrasive for sandblasting, and whether the size or grain size of the abrasive particles is important.
The content of the article
Types of abrasives for sandblasting
There are 7 main types of abrasives for sandblasting:
- Sand.
- Slag (nickel and copper).
- Plastic shot.
- Glass shot.
- Garnet.
- Alund.
- Metal shot.
Let's look at them one by one:
- Sand. As mentioned, sand was used for a long time as the only abrasive material. Quartz sand is the most popular and cheapest material for sandblasting.When using sand as an abrasive, additional protection is required - a gas mask and special clothing. When sand granules hit the surface, they break down - breaking into even smaller particles. This dust becomes airborne and can enter the lungs, causing harm to the user. Because of this, some countries have banned the use of quartz sand in sandblasting machines. Sand as an abrasive is most effective when cleaning stone and concrete surfaces.
- Abrasive slag. Made from slag of copper, nickel or their alloys. The result is a powder with small granules, which is used in classic open sandblasts. Abrasive slag granules are better than sand at cleaning the surface of rust and paint. This is due to their increased hardness. And due to its relatively high mass, powdered slag forms a small amount of dust, which does not settle in the air. Abrasive slag can be reused. Reusing abrasive material is called recovery.
- Plastic shot. The plastic is turned into a powder with soft granules. This material is used for delicate work - cleaning thin-sheet soft metals, plastic, surfaces made of glass, wood, ceramics and other materials. Plastic beads are often used to clean car bodies or remove powder coatings from them. The plastic abrasive material is environmentally friendly. The cost of such a fraction is high, and it cannot be reused.
- Granulated glass. The glass is broken into very small particles. These granules are used mainly in industry, in production. They cover the glass, making it matte, finish the surfaces, and process high-precision glass elements - lenses.Abrasive glass is used in glass processing in mechanical engineering. It does not pollute the environment.
- Garnet sand. Also known as garnet. Specially formulated mineral powder. It is characterized by high hardness and mass of granules, and the possibility of reuse. When using garnet in sandblasting, dust is generated. Garnet is produced abroad, the average cost of this material is 45 rubles per kilogram.
- Alund. Alundum or corundum is a powder made from aluminum oxide. Its granules are distinguished by high hardness and increased mass. Electrocorundum can be reused. Electrocorundum has a high cleaning cost.
- Metal shot. Most often it is made of steel or cast iron. Small fractions of various shapes. Used for sandblasting surfaces of high and medium hardness. Metal shot granules come in different sizes, which determines the efficiency and speed of cleaning with this abrasive. Fine metal shot is used for cleaning thin layers or soft surfaces, while coarse shot is the opposite.
Characteristics of types of abrasive
In the table below we will compare for you all seven types of sandblasting abrasives.
| Sand | Slag | Plastic shot | Abrasive glass | Garnet sand | Alundum/corundum | Metal shot | |
| Dust when using | Formed in large quantities | Formed | Minimum | Small education | Small education | Small education | Not formed |
| Pure Quartz Content | Up to percent | Up to percent | No quartz included | High (more than percent) | Up to percent | No quartz included | No quartz included |
| Hard/brittle material | Unstable, fragile | Hard, brittle | Not hard, not fragile | Medium hardness and brittleness | Medium hardness and brittleness | Increased hardness, non-brittle | Increased hardness, non-brittle |
| Reuse (recovery) | No | Yes, up to three times | Yes, up to 10 times | Yes, up to 30 times (depending on glass type) | Yes, up to 6 times | Yes, up to 6 times | Yes, cast iron up to 12 times, steel up to 100 (depending on the steel) |
| How much is spent per square meter | ±90 kilograms | ±45 kilograms | 5 kilograms | 7 kilograms | From 0.5 (steel), to 7 kilograms (cast iron) | ||
| Material price | 2-5 rubles/kilogram | 2-7 rubles/kilogram | 5-10 rubles/kilogram | 100 rubles/kilogram | 45 rubles/kilogram | 150-200 rubles/kg | 100-150 rubles/kg |
| Terms of Use | Indoor dust suppression or outdoor cleaning | Outdoor cleaning | Specialized equipment with cameras, ventilation or dust-free sandblasting | Specialized equipment with cameras, ventilation or dust-free sandblasting | Specialized equipment with cameras, ventilation or dust-free sandblasting | Specialized equipment with cameras, ventilation or dust-free sandblasting | Specialized equipment with cameras, ventilation or dust-free sandblasting |
| What is it used for? | Superficial primary cleaning | Superficial primary cleaning | Removing paint, removing uneven surfaces from soft surfaces | Finishing, removing the top layer | Superficial primary cleaning | Removing the dense top layer | Material strengthening, finishing, cleaning |
Are the size and grain size of the abrasive particles important?
Yes, they are important. Different granule sizes and grain sizes affect efficiency, surface processing speed, relief and texture. The larger the abrasive granules, the deeper they penetrate the layer. Sizes of granules of abrasive materials:
- Big ones.
- Average.
- Small ones.
They can be compared to brushes when drawing - large brushes are inconvenient for painting small areas, and you can accidentally ruin the drawing. Large granules will knock off the layer, but can also damage the material itself, so they are used to clean hard surfaces - metals, steel, concrete. Small granules will not be able to remove several layers of paint due to their size - they do not go deep. Fine granules are used to remove the thin top layer of medium-hard materials.
