What is Shot Blasting?
Shot blasting is a mechanical cleaning process that uses spheres made of abrasive material to remove oxides and other debris from the surface of another material. Shot blasting belongs to the same family of abrasive blasting processes in which also sandblasting is categorized; however, there are essential differences between it and sandblasting. Shot blasting uses spherical shot as an abrasive media and a centrifugal wheel for propulsion while sandblasting uses grains of sand and almost exclusively uses compressed air for propulsion. Not to mention that sandblasting is now an illegal method in the UK due to the high risk of silicosis in workers exposed to abrasive blasting with silica, and the hazard is difficult to control.
What Materials Can Be Shot Blasted?
Shot blasting is a cleaning method that can be used on many types of materials, including but not limited to:
- Carbon Steel
- Stainless Steel
- Cast Iron
- Titanium
- Copper
- Other Ceramic Types
There are other materials upon which shot blasting can be used for, enquire now for more details.
How Does Shot Blasting Work?
Shot blasting is a cleaning process in which abrasive materials are propelled at high velocity against a material surface to clean it. The most common way to propel shot-blasting media is through a centrifugal wheel. Once the wheel accelerates to the desired velocity, the shot blast material is expelled from the wheel and into a gun, which directs its flow onto the cleaned surface. Many shot blasting equipment cells also include a recovery system that collects material shot propelled against the cleaned material and returns it to be used again. The Shot blasting recovery is performed through the use of a vacuum alongside the blasting system.
The technique of shot blasting is a much more aggressive abrasive process than sandblasting. Shot blasted materials are often used for large and difficult-to-prepare objects that need a strong application force and denser media material to clean and prepare surfaces. Shotblasting also requires strict containment as the force of the blasted shot could cause collateral damage if the process isn’t confined.
Shot Blasting Equipment
Shot blasting uses wheel blast equipment to propel abrasive media on surfaces being treated for final finishing. The process involves throwing media at a surface rather than blowing it. Standard equipment used in shot blasting systems includes:
- Hanger blast equipment can be fitted with trolleys and hung on manual Y-track monorails for specific shot blasting operations.
- Table blasters are components with direct drive wheels mounted inside the blast cabinet.
- Tumble blasting equipment allows continuous blasting cycles with continual abrasive recycling. Tumble blast machines have built-in rubber belts and steel flight models in different sizes.
- Certain shot-blasting equipment is designed to remove rust and old paint from all forms of metal cylinders.
- Swing table blast wheels are direct drive, allowing them to swing out for loading and unloading abrasive media.
Types of Shot Blasting Media
The type of shot blast media you use depends on the desired result you want to achieve. Blasting media comes in various densities, hardness, shapes, and particle sizes. Depending on the job at hand will depend on the type of media we will use. See below for a list of media we can use to complete the required project.
- Steel
- Copper
- Zinc
- Aluminium
There are other options for which media can be used when it comes to blasting, but this will usually fall out of shot blasting and fall into another category of blasting, which you can find more information about on our abrasive blasting page.
Health & Safety
One advantage of shot blasting over alternative abrasive blasting methods is that shot blasting produces less dust. The dust produced by other abrasive methods, such as sandblasting, can be inhaled unintentionally if safety measures are not in place.
Shot blasting reduces this risk, although some dust will be produced from the cleaned material. In addition to respiratory safety, shot blasting requires safety measures that prevent employees from being impacted by propelled or ricocheted steel shots.
- Shot Blasting Suit – Our team must wear a full-body suit while blasting to prevent particles from getting into their clothing or exposed skin.
- Shot Blasting Respirators – Our staff use a contained breathing apparatus (SCBA) when dry blasting. This device prevents accidental inhalation of any media particles we use. Our respirators are properly fit-tested to ensure respiratory protection is not compromised when we are working.
- Gloves and Boots – Our hands and feet are always protected with the required safety-enhanced boots and gloves.
- Hearing Protection – Again, simple earplugs can work well at keeping out loud noises from shot blasting; we prefer noise-cancelling headsets.
- Face Shields and Helmets – Full head coverage is what we use; yes, standard face shields and goggles can be used, but we prefer to cut no cost when it comes to the health and safety of our team, resulting in us using full head gear.
Health and safety at NEBC is paramount; we take no risks and spare no expense on keeping our staff, clients and the public safe.
Shot Blasting or Sandblasting?
Regarding abrasive blasting, sandblasting is usually the first thing to come to people’s thoughts. Still, sandblasting is now a technique that has since been banned due to NIOSH recommending since 1974 that silica sand (or other substances containing more than 1% crystalline silica) be prohibited as abrasive blasting material. Knowing the differences in the blasting techniques is essential to match your required work to the recommended blasting technique.
So, if you’re looking for key differences between shot blasting and sandblasting, here are a couple; Shot blasting is a suitable method for preparing thick and heavy surfaces like metal hulls, truck hubs and gears. Sandblasting might be too gentle and time-consuming for these tasks, but shot blasting will quickly remove rust and paint from these objects.
Selecting Your Shot Blasting Media
When it comes to selecting the type of media you are going to be using, it’s essential to make sure that the project desired goals are a priority. Because depending on the materials you are blasting, selecting the suitable media is necessary. See below the considerations you should be making when choosing the correct blasting media.
- Shape: For example, round-shaped particles are less abrasive than angular-shaped particles.
- Size: Media particle size is measured in mesh, which refers to a screening determined by the number of holes per square inch where fine media size filters through more holes in a mesh screen than larger particles.
- Hardness: Hard particles, such as steel shot, penetrate deeper into materials than soft media, such as plastic particles. The hardness of the blasting media must be compatible with the surface to avoid damage.
- Density: Dense media particles have more mass per unit volume than lightweight particles. The proper media density is essential to do the job efficiently without compromising the treatment surface.
Mobile Shot Blasting
If your equipment/material/structuring requires shot blasting before coating, we can offer a remote/mobile on-site service, reducing disruption within your business. Our mobile service can optimise turnaround times due to no need for delivery services.
Our Shot blasting techniques, including dustless blasting, make it straightforward for us to come to your site and work within your business and structure. Saving time and resulting in a reduction in costs too. We understand that disruption of business can significantly impact day-to-day proceedings.