Gentle Power: Delicate Sand Blasting

Delicate sandblasting is a process that uses compressed air to propel abrasive materials at a surface to smooth or roughen it. It is often used to clean and prepare surfaces, remove paint, or create decorative effects. While the name suggests the use of sand, other materials such as glass beads, walnut shells, and baking soda are more commonly used today due to health and environmental concerns associated with sand. Delicate sandblasting is particularly effective on delicate surfaces like wood, as it can remove dirt, grease, and paint without damaging the underlying substrate. This process is also known as abrasive blasting and has been used for decades in various applications, from art to industrial cleaning.

Sandblasting equipment

Delicate sandblasting requires the right equipment to achieve the desired results without causing damage. Here is a guide to the different types of sandblasting equipment available:

Sandblasting, or abrasive blasting, is a process that uses abrasive materials to remove paint, rust, corrosion, and other surface contaminants. It is used in various industries, including automotive, construction, and manufacturing, for tasks like cleaning, surface preparation, and removing old coatings.

Types of Sandblasting Equipment

Portable Sandblasting Equipment:

• Abrasive Blaster Pots: Pressurized tanks that allow blasting grit into the main blasting line. They are effective for small jobs or restricted spaces and can be used in wet blasting by mixing the abrasive with water or another liquid.
• Blast Machines: Similar to blaster pots but larger, allowing for use on bigger projects. The operator controls the abrasive flow with a handle, and the equipment is portable for easier maneuverability.

Cabinet Sandblasting:

• Zero Blast Cabinets: Closed-loop systems that recycle abrasive material and contain dust. They consist of a cabinet, abrasive blasting system, recycling system, and dust collection system. Gloves attached to the cabinet protect the operator.
• Siphon Blast System: Creates a vacuum with compressed air, pulling the abrasive into the blast gun and nozzle.
• Pressure Blast System: Pressurizes a vessel containing the abrasive, which is attached to the blast hose and nozzle.
• Wet Blast Cabinet: Injects the abrasive slurry into a gas stream to reduce heat generated during dry blasting.

Specialized Sandblasting Equipment:

• Empire Equipment: Offers batch processing machines, in-line blast systems, and continuous processing machines for various sandblasting needs.
• Special Application Equipment: Designed to work with other sandblasting equipment, including wet-blast attachments and suction guns.

Choosing the Right Sandblasting Equipment

The choice of sandblasting equipment depends on the specific application, the material being worked on, and the desired finish. For delicate sandblasting, bead blasting is often used, as it employs less abrasive glass beads, resulting in a smoother, satin-like finish. It is suitable for cleaning delicate parts and creating a uniform matte finish.

Additionally, the PSI (Pounds per Square Inch) setting is crucial for achieving the desired results without causing damage. Delicate work may require lower PSI settings, while heavy-duty tasks can utilize higher PSI. It is essential to refer to the manufacturer's guidelines and consider factors such as abrasive material, surface nature, and safety precautions when determining the optimal PSI.

Sandblasting nozzles

Nozzles are a key component of sandblasting equipment. The mixture of sand and air travels through a hand-held nozzle to direct the particles toward the surface or workpiece. Nozzles come in a variety of shapes, sizes, and materials. Boron carbide is a popular material for nozzles because it resists abrasive wear well.

When using a blast nozzle, it is important to ensure that the tip rotates at high speed. This allows the material to be forced out of the machine's hose and onto the desired surface.

There are several types of nozzles available, including:

• Straight nozzles: Used for rough or heavy blasting.
• Tapered nozzles: Used for smooth, dull, or final blasting.
• Diamond nozzles: For high performance and efficiency.
• Fluted nozzles: For low-pressure and gentle cleaning of soft materials like wood and cloth.
• Reinforced flutes: For heavy-duty applications such as removing paint from concrete walls.

Additionally, the BlastOne website offers a range of heavy-duty sand and abrasive blast nozzles, including:

• SnakeBite XP Blast Nozzle: A high-performance nozzle with advanced modelling that results in very fast cleaning speed.
• SnakeBite XQ Blast Nozzle: The world's quietest blast nozzle, offering up to 16dBA noise reduction and up to 45% less fatigue compared to standard blast nozzles.
• SnakeBite Flex Blast Nozzle: A compact and lightweight version of the SnakeBite nozzle, offering the same noise reduction and fatigue improvement features.
• SnakeBite Strike #10 Blast Nozzle & Silencer Assembly: The highest productivity handheld blast nozzle available, offering double the productivity of a #8 high-performance blast nozzle with less operator fatigue.

When selecting a sandblasting nozzle, it is important to consider factors such as the volume of air your air compressor can supply per minute (CFM) and the desired nozzle pressure (PSI) for productive blasting, typically maintained at 100 PSI. The greater the compressed air supply, the larger the blast hose and nozzle that can be used.

Sandblasting applications

Sandblasting has a wide range of applications, from industrial cleaning to art. Here are some of the most common uses:

Removing Rust and Corrosion

One of the most common applications of sandblasting is to remove rust and corrosion from metal surfaces, especially ferrous metals like iron and steel. This process uses a pressure blaster with a heavier cutting medium, such as aluminium oxide.

Cleaning Smaller Tools and Machinery

Sandblasting is also useful for cleaning smaller items, such as hand tools, household hardware, and automobile and metal tools. It can quickly remove rust from tools and machinery clogged with oil, dirt, and grease, helping to prevent breakdowns and wear and tear.

Smoothing and Polishing

Sandblasting can be used to smooth and polish metal and plastic surfaces, removing burrs, tags, and excess material to ensure productive assembly. It can also be used to soften sharp edges. For this application, a gentler medium such as walnut shells or crushed glass is often used.

Creating Art and Designs

Sandblasting is a well-known technique for creating art and designs on various surfaces, including wood, metal, glass, and other materials. Artisans use this method to carve intricate patterns and create lasting, custom appearances. It is often used for etching glass and creating ornamental designs in glass, plastic, and metal.

Cleaning Concrete and Brick Surfaces

Sandblasting is an effective method for cleaning concrete, brick, and stone surfaces, such as streets, walkways, and pavements. It can quickly and efficiently remove dirt, grease, and other contaminants without wasting water. This process can also be used to restore the authentic look of bricks and stones by removing paint, mortar, and other substances.

Surface Preparation

Sandblasting is commonly used to prepare surfaces for painting, coating, or bonding. It helps create a smooth surface for better adhesion and can be used on various materials, including metal, wood, and concrete. This process ensures that the final coating will last longer and have a better appearance.

Mold and Mildew Removal

Sandblasting is an effective method for removing mold and mildew from structures. A gentler medium, such as soda or baking soda, is used for this application to avoid damaging the surface. This technique is often used in homes and landscaping to eliminate health issues caused by mold, such as itchy eyes, coughing, and asthma attacks.

Removing Oil Stains

Sandblasting can be used to remove oil stains from driveways and concrete floors. Wet blasting is typically used for this application, as it combines hot water, soap, and a blasting agent to break down and remove tough stains.

Fire Damage Clean-Up

Sandblasting is often used for fire damage restoration to remove soot and stains. It can be applied to both soft materials like wood and masonry. This process helps to restore surfaces affected by fire and smoke damage.

Restoring Vintage Hardware

Sandblasting is ideal for restoring old hardware, such as screws, bolts, and nuts, to their original condition. It removes dirt, paint, rust, and grease, preparing the hardware for further restoration processes.

Sandblasting techniques

Delicate sandblasting techniques are used for cleaning and restoring surfaces without causing damage. Here are some of the key methods used for more intricate and precise applications:

Wet Sandblasting

Wet sandblasting involves mixing water with the abrasive material before propelling it onto the target surface. This method is effective in minimising airborne particles and is often used in sensitive environments. It is particularly suitable for delicate surfaces, such as historical artefacts or soft stones, where minimising damage is crucial. The water also helps to control dust, lubricate the surface, and enhance the efficiency of the abrasive material, reducing overall consumption.

Bead Blasting

Bead blasting uses small glass beads as the abrasive material. This technique is known for providing a smooth finish without damaging the underlying surface. The glass beads are spherical and less abrasive than traditional sand, making it a preferred choice for cleaning and peening surfaces in applications such as automotive body work and pool tile cleaning.

Soda Blasting

Soda blasting utilises sodium bicarbonate (baking soda) as the abrasive material. This gentle yet effective method is suitable for various applications, especially when working with sensitive materials. It is commonly used for cleaning and de-painting surfaces like wood, fibreglass, and certain metals. Its environmentally friendly nature, due to the non-toxic and water-soluble properties of baking soda, makes it a preferred choice for projects concerned with environmental impact.

Vapor Blasting

Vapor blasting, also known as wet blasting or liquid honing, is a technique that involves using a slurry mixture of water, abrasive media, and compressed air. The addition of water controls dust, cools the abrasive particles, and enhances overall efficiency. This method is renowned for its gentle approach, making it suitable for delicate surfaces while still achieving effective cleaning. Vapor blasting provides a consistent and uniform surface finish and is applicable across a wide range of materials and industries.

Micro-abrasive Blasting

Micro-abrasive blasting is a dry abrasive blasting process that uses small nozzles to deliver a fine stream of abrasive material to a small area with high precision. This technique is accurate enough for intricate tasks such as writing on glass or cutting patterns in eggshells. It is commonly used for light etching of metal surfaces and surface finishing on plaster and concrete.

Vacuum Blasting

Vacuum blasting, also known as dustless blasting or closed-circuit blasting, combines abrasive blasting with a powerful vacuum system. This method effectively captures and contains the abrasive media and removed contaminants, preventing their dispersion. It ensures a dust-free operation, making it suitable for sensitive environments and enclosed spaces. Vacuum blasting is applicable to a range of materials, including metals, concrete, and wood, and is often used in construction, restoration, and shipbuilding projects.

Dry Ice Blasting

Dry ice blasting, or CO2 blasting, involves propelling small pellets of dry ice at high speeds to clean and prepare surfaces. The dry ice pellets are extremely cold, harnessing both thermal and kinetic energy to remove contaminants. This non-abrasive and non-conductive process is safe for delicate surfaces and electrical components. It is environmentally friendly, as the dry ice sublimates upon contact, leaving no residue or secondary waste. Dry ice blasting is commonly used in industrial equipment cleaning, restoration projects, and the food and beverage industry.

Sandblasting safety

Sandblasting, or abrasive blasting, is a potentially dangerous process that requires extensive training and safety protocols to be followed. Here are some key considerations for sandblasting safety:

Secure the Environment

It is important to keep the blasting area free of hazards that could lead to slipping, tripping or falling. Eating, drinking and smoking should be prohibited around the blasting area, and all ventilation, air compressors, power supplies and wash stations should be fully functional.

Check Equipment

All equipment should be regularly checked for cracks and other damage. This includes the blast hose, which should be inspected for leaks. Less toxic abrasives should be used where possible, and blasting equipment should be kept in proper containment structures. It is also vital to test breathing filters and carbon monoxide monitors daily.

Protective Gear

Workers must be provided with protective clothing, including helmets, gloves, safety footwear, earplugs, safety goggles and respirators. Respiratory protection is critical, and respirators must be NIOSH-certified and cover the head, face, neck and shoulders.

Cleanup Procedures

Water-based cleaning methods or HEPA-filtered vacuuming systems should be used to clean the area after sandblasting. Compressed air should be avoided as it will disperse dust.

Training

All workers should be trained on the risks involved with sandblasting and the measures required to stay safe. They should also be made aware of the specific dangers of the materials they are working with, as outlined in safety data sheets.

Noise

Sandblasting is a noisy operation, and hearing protection should be provided to all workers.

Ventilation

Well-maintained ventilation systems are crucial to prevent dust accumulation and to increase visibility and operator safety.

Other Considerations

Other general safety considerations include keeping unauthorised personnel away from blasting areas, scheduling sandblasting for favourable weather conditions and when fewer workers are present, and regularly decontaminating equipment.

Frequently asked questions