Sandblasting is a surface finishing method that cleans the surface of metals, what is sandblasted metal and what does sandblasting do? Let’s get into some basics of metal sandblasting.
What is Sandblasted Metal?
Sandblasted metal refers to a type of metal surface treatment that involves blasting the metal surface with a high-pressure stream of abrasive material, typically sand, to create a textured or frosted appearance. The abrasive particles remove a fine layer of material from the surface, leaving behind a rougher texture that can be used for decorative or functional purposes. Sandblasting can be used on a variety of metals, including steel, aluminum, copper, brass, and others. The process can be controlled to create different textures, ranging from a fine sand-like texture to a more aggressive, pitted surface. Sandblasting can be used to create a uniform finish across an entire surface, or it can be used to selectively remove material to create patterns or designs.
Sandblasted metal can be used in a variety of applications, including architectural design, industrial machinery, automotive parts, and more. The textured surface can be useful for providing a better grip or reducing glare, and can also be used to hide scratches or other imperfections in the metal surface.
Does Sandblasting Remove Rust?
Yes, sandblasting is an effective method for removing rust from metal surfaces. When rust forms on a metal surface, it creates a layer of oxide that is weaker than the underlying metal. Sandblasting can remove this layer of oxide and any loose or flaking rust, leaving behind a clean and smooth surface.
To remove rust with sandblasting, an abrasive material, such as sand or grit, is propelled at high speed onto the rusted surface using compressed air or a blasting machine. The abrasive particles work to chip away the rust, leaving behind a clean surface that is free of rust and other contaminants.
However, it is important to note that sandblasting can also remove a thin layer of the metal surface along with the rust. This can be problematic if the metal is already thin or weak. Additionally, sandblasting can create small pits or scratches on the surface, which can lead to future rust formation. Therefore, it is important to consider the condition of the metal before sandblasting and to take appropriate measures to prevent rust formation after sandblasting.
Does Sand Blast Use Sand?
Although sandblasting was originally named for the use of sand as the abrasive material, many modern sandblasting methods do not use actual sand. The reason for this is that sand contains silica, which can be harmful if inhaled, potentially causing lung damage and other health issues. Now, sandblasting uses a variety of different abrasive materials, depending on the desired surface finish and the material being treated. Some common abrasive materials include steel grit, aluminum oxide, glass beads, crushed walnut shells, and plastic beads. These materials are safer to use than sand and can provide similar or even better results.
In addition to the type of abrasive material used, other factors such as the pressure of the air or water used to propel the abrasive particles and the size and shape of the nozzle used can also affect the effectiveness of sandblasting and the resulting surface finish.
Alternatives to Sandblasting Steel
There are several alternatives to sandblasting, depending on the specific application and the material being treated. Here are some common alternatives to sandblasting:
– Soda blasting: This method uses sodium bicarbonate (baking soda) as the abrasive material. It is a gentler method than sandblasting and is often used to clean delicate surfaces, such as those made of glass or wood.
– Water blasting: Also known as pressure washing, this method uses a high-pressure stream of water to remove contaminants from a surface. It can be effective for removing dirt, grime, and some types of coatings, but may not be as effective as sandblasting for removing heavy rust or paint.
– Abrasive blasting with other materials: As mentioned earlier, there are several types of abrasive materials that can be used for blasting, such as steel grit, aluminum oxide, glass beads, crushed walnut shells, and plastic beads. Each of these materials has different properties that can make them more or less effective for a particular application.
– Chemical stripping: This method uses chemicals to dissolve or soften the coating on a surface, allowing it to be removed more easily. It is often used for removing paint or other coatings from metal surfaces.
– Mechanical methods: In some cases, mechanical methods such as grinding or sanding may be effective for removing surface contaminants or coatings. These methods are often slower and more labor-intensive than blasting methods but can be useful for certain applications.
What Does Sandblasting Do?
Sandblasting is a surface treatment process where a stream of abrasive material—usually sand, glass beads, or other fine particles—is propelled at high speed against a surface using compressed air or water. The main purposes and effects of sandblasting are:
Surface Cleaning: Removes rust, scale, old paint, grease, and other contaminants from metal, wood, or concrete surfaces.
Surface Preparation: Creates a slightly roughened texture, improving adhesion for paints, coatings, or adhesives.
Deburring & Smoothing: Eliminates sharp edges, burrs, or irregularities on metal castings, machined parts, or molded components.
Surface Finishing & Decoration: Can give a matte, satin, or textured finish for aesthetic purposes on metal, glass, or stone.
Restoration & Maintenance: Used in cleaning old machinery, monuments, or buildings to restore surfaces to their original state.
Sandblasting Steel Applications
Sandblasting is widely used in steel processing and fabrication to clean, prepare, and finish steel surfaces:
Surface Cleaning: Removes rust, scale, oxidation, oil, grease, and old paint from steel surfaces before coating or painting.
Surface Preparation: Creates a uniform rough texture (profile) on steel, improving adhesion for paints, primers, and protective coatings.
Deburring & Edge Treatment: Smooths out sharp edges or burrs on fabricated or machined steel parts.
Surface Finishing & Texturing: Produces decorative finishes like matte, satin, or uniform textures on stainless steel or architectural steel components.
Maintenance & Restoration: Cleans structural steel, pipelines, bridges, or industrial equipment to extend service life and prevent corrosion.
Coating Removal: Efficiently removes old coatings, scale, or welding slag from steel before repainting or recoating.
Sand Types Used in Sandblasting
| Abrasive Type | Characteristics | Typical Use |
|---|---|---|
| Silica Sand | Natural sand; sharp and hard | Traditional steel cleaning, but restricted in many regions due to health risks (silicosis) |
| Aluminum Oxide | Very hard, reusable, sharp edges | Heavy-duty cleaning, rust removal, and profiling steel for coatings |
| Glass Beads | Smooth, round; less aggressive | Polishing, finishing, and peening steel without damaging the surface |
| Steel Grit / Shot | Hard, angular (grit) or spherical (shot) | Aggressive cleaning, rust removal, surface texturing, and peening for fatigue resistance |
| Garnet | Hard, sharp, and environmentally friendly | Industrial steel cleaning, abrasive blasting, and surface preparation |
| Plastic or Walnut Shell | Softer, non-metallic | Finishing, deburring, or cleaning delicate steel surfaces without scratching |
What is Sandblasting Price?
Sandblasting typically costs around £75 per hour. Dry ice blasting is significantly more expensive, around £300 per hour, because it’s a specialized, non-abrasive cleaning method that leaves no residue. Sandblasting is more traditional, abrasive, and suitable for cleaning or preparing surfaces like metal, wood, or masonry.
Advantages of Sandblasting Metal
Thorough Cleaning: Effectively removes rust, scale, paint, grease, and other contaminants, leaving a clean surface for further processing.
Improved Coating Adhesion: Creates a uniform rough texture (surface profile) that enhances the bonding of paints, primers, powder coatings, and other finishes.
Deburring and Edge Smoothing: Eliminates sharp edges, burrs, and minor imperfections from castings, machined parts, and metal sheets.
Surface Finishing and Aesthetics: Provides a consistent matte, satin, or decorative finish for both functional and decorative applications.
Corrosion Prevention: By removing rust and old coatings, it prevents further corrosion and extends the lifespan of metal components.
Versatility: Works on a wide range of metals, including steel, stainless steel, aluminum, brass, and copper.
Efficiency and Speed: Cleans large or complex metal surfaces much faster than manual methods like wire brushing or sanding.
Surface Restoration: Restores old or weathered metal surfaces to near-original condition, useful for maintenance, restoration, or refurbishment projects.