Difference Between Sand Blasting & Shot Blasting

Sand blasting and shot blasting are both types of surface preparation methods used to clean and smooth surfaces before painting or coating. Both methods use a high-pressure stream of abrasive particles to remove dirt, rust, old paint, and other unwanted materials from the surface. However, there are some key differences between the two methods.

• Sand blasting is a dry abrasive blasting process that uses compressed air to propel a stream of abrasive particles, typically made of silica sand, at high speeds onto a surface. The abrasive particles remove the unwanted materials from the surface through a process of abrasion, or erosion. Sand blasting is commonly used to clean and smooth surfaces such as metal, wood, and concrete, and to remove paint and rust from surfaces.
• Shot blasting, on the other hand, is a wet abrasive blasting process that uses a high-pressure stream of abrasive particles suspended in water to clean and smooth surfaces. The abrasive particles, typically made of steel, aluminum oxide, or other materials, are propelled at high speeds onto the surface by compressed air. The water helps to control the dust generated by the blasting process and also cools the surface. Shot blasting is commonly used to clean and smooth surfaces such as metal, brick, and concrete, and to remove paint and rust from surfaces.
• Sand blasting uses silica sand as the abrasive particle while shot blasting uses a range of abrasive particles including steel, aluminum oxide, and others, this directly affects the surface which is more appropriate for each process. Another key difference is the way the abrasive particles are propelled onto the surface. Sand blasting uses compressed air, while shot blasting uses compressed air in conjunction with water.
• Sand blasting is also a more aggressive method of surface preparation, removing more material from the surface and leaving it with a rougher texture. Because of this, sand blasting is typically used for heavy-duty cleaning and surface preparation, such as removing heavy rust or old paint. Shot blasting, on the other hand, is a gentler method that leaves the surface with a smoother texture, making it more suitable for preparing surfaces for painting or coating.

Abrasives Used in Sand Blasting & Shot Blasting

The abrasives used in sand blasting and shot blasting are different types of materials that are used to remove dirt, rust, old paint, and other unwanted materials from surfaces.

In sand blasting, the abrasive material is typically made of silica sand. Silica sand is a hard, angular, and durable material that is effective at removing paint, rust, and other unwanted materials from surfaces. It is also relatively inexpensive and widely available.

In shot blasting, the abrasive materials can vary. Some common types of abrasive materials used in shot blasting include:

• Steel shot: Steel Shots are made from spherical steel balls and are commonly used for cleaning and smoothing metal surfaces, as well as for removing paint and rust.
• Steel grit: This is made from angular pieces of steel and is commonly used for cleaning and smoothing metal surfaces, as well as for removing paint and rust.
• Aluminum oxide: This is a man-made abrasive that is hard and durable, making it effective for cleaning and smoothing a variety of surfaces.
• Glass beads: These are made from spherical glass beads and are commonly used for cleaning and smoothing a variety of surfaces, as well as for removing paint and rust.
• Plastic abrasives: These are also called urea, melamine, and polyester abrasives, they are made of plastic material and can be used to clean delicate surfaces such as fiberglass, plastic parts, and some metal surfaces.

Types of Sand Blasting Machine

The choice of abrasive material will depend on the type of surface to be cleaned and the level of cleaning required. Each abrasive has its own unique properties, such as hardness and shape, that make it more or less effective for different types of surfaces and cleaning tasks.

There are several types of sand blasting machines that are used for different types of sand blasting applications. Some of the most common types include:

• Portable Sand Blasting Machine: Portable Sand Blasting Machine is a smaller, handheld sand blasting machine that are typically used for small, localized sand blasting tasks. They are designed to be easily transported from one job site to another and are commonly used for small-scale cleaning and surface preparation tasks.
• Sand Blasting Cabinet: These are enclosed sand blasting machines that are designed to contain the blasting process and contain the dust generated. Sand Blasting Cabinet are typically used for larger, more complex sand blasting tasks and are commonly used in industrial settings such as factories and warehouses.
• Pressure Blasting Cabinet: These are sand blasting machines that use a pressurized pot to propel the abrasive media onto the surface. These types of sand blasters are typically used for removing coatings, rust, and other unwanted materials from large surfaces, such as ships and bridges.

• Suction Blasting Cabinet: These are sand blasting machines that use a suction system to draw the abrasive media onto the surface. These types of sand blasters are typically used for removing coatings, rust, and other unwanted materials from large surfaces, such as buildings and structures.
• Automatic Sand Blasting Machine: These are sand blasting machines that are designed to automatically feed the abrasive media onto the surface i.e it is known as Automatic Blasting Machine. These types of sand blasters are typically used in industrial settings where large amounts of sand blasting are required and are commonly used for cleaning and surface preparation tasks in manufacturing and production settings.
• Vapor Sand Blasting Machine: These are sand blasting machines that use a mixture of abrasive and water, creating a slurry that is propelled onto the surface. This type of blasting is less aggressive than dry blasting and is typically used for cleaning delicate surfaces such as electronics and aerospace components.

The choice of sand blasting machine will depend on the type of task and surface to be cleaned, as well as the level of cleaning required. The size, power, and efficiency of the machine will also play a role in determining the best option for a particular job.

Safety Measures for Sand Blasting & Shot Blasting

In terms of safety, sand blasting can be more dangerous because of the potential for silicosis, a lung disease caused by inhaling silica dust. OSHA regulates the exposure limit to silica dust and provides a guideline for the sand blasting operation, Shot blasting is generally considered to be safer because the water helps to control the dust and protect operators from inhaling harmful particles.

In conclusion, both sand blasting and shot blasting are effective methods of surface preparation, but they are best suited to different types of projects. Sand blasting is a more aggressive method that removes more material and is best suited for heavy-duty cleaning and surface preparation. Shot blasting is a gentler method that leaves the surface with a smoother texture and is more suitable for preparing surfaces for painting or coating.