Shot Blasting Process

The Shot Blasting Process

What is shot blasting?

Although the terms shot blasting and sand blasting are often used interchangeably, they’re not the same. The shot blasting process is used in order to remove impurities or a layer from a surface. It achieves this by using abrasive materials that are fired at high speed at the target.

Why is shot blasting used?

As an essential part of a number of treatment processes, shot blasting has many unique uses. It can help shape and remove impurities, such as rust, mill scale and previous coatings from tougher denser metals. It can facilitate peening, the mission-critical cold working process that involves the use of metal shot to create plastic deformation, or ‘strain hardening’. This allows the material to withstand greater stresses without buckling. It can be used in the pre-treatment process to provide a better surface roughness for paint, nickel coating, powder coating and more. It can also provide quick and efficient cleaning of metals and materials, as well as rust-removal.

How do you assess a shot blasting situation?

It is important to fully understand your materials and decide on your end goal, such as aluminium shot blasting. What do you want to achieve through the shot-blasting process. Do you need to peen the material, remove rust, or prepare it for a protective coating? If you are intending to carry out relatively fine work such as cleaning smaller metal objects such as screws and parts, a smaller hand-held device may be most appropriate. If larger items such as chassis, lengths of pipe or building materials are to be blasted, choosing a larger enclosed option might be a better choice.

What is the shot-blasting process?

There are many different options available when it comes to applying shot to your chosen material, they will fall into two key categories:

● Air Blasting Work: This involves the use of compressed air to drive your chosen type of steel abrasive toward its target. This can be accompanied by a range of automated options to help ensure the highest standards of safety, coverage, and quality. This is most often used on specialist or larger items, or field applications.

● Mechanical Blasting Work: This involves the steel shot or grit being driven toward a target through the use of powered turbines. This helps speed the process and provides quick coverage without compromising on quality. This is most often used in industrial settings or for continuous processes.

The basic principle behind both of these shot blasting processes is the same. The particle is accelerated, either by compressed air or wheel speed, and given kinetic energy. It is thrown at the work piece, where some of the kinetic energy is transmitted to the surface. The amount of energy transferred depends on a number of factors, including size and hardness of the particle, as well as type of steel and abrasive quality. This impact removes impurities and a small amount of material from the surface. The abrasive rebounds and hits other parts of the work piece, or is returned to a hopper to be re-used. Smaller abrasive particles and the impurities removed from the work piece are removed as waste. The process is repeated until the desired finish is achieved.

When the cycle of work is complete, the equipment is safely shut down and the material assessed. The number of cycles should always be agreed in advance to save on time and effort but can potentially be ‘eyeballed’ on unique or sensitive pieces. If more work is required, the process is repeated. If the correct amount of abrasion has been applied, the process stops, and the shot and detritus is safely cleared away.

Health and Safety Considerations

As with the use of any kind of high-powered machinery, shot blasting has some health and safety risks. The shot blasting process will have small and fine pieces of material, like metal, being fired at high speeds into a solid piece of machinery to take off the surface level. This means that hazardous materials will be present in the work area, so you will need to take proper protection and wear suitable protective clothing. Eye and ear protection should be worn, as well as a mask to prevent the accidental inhalation of abrasive and dust. Adequate space should be provided to ensure that anyone working nearby isn’t impacted by the process.

How can Ervin help?

Not all shot blasting processes are going to work for all applications. Some abrasive blasting processes are for cleaning and others can be cutting. It is best to speak to a specialist before committing to shot blasting to get the right solution for you. One of the biggest factors to success is choosing the right grade of high quality steel shot or grit, a process which Ervin can help you through. Shot blasting can be extremely difficult to master and our team is on hand to provide the professional guidance and world class quality of service that you need.
Contact our experienced team to discuss how we can help.